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Earth and Moon and Sun of Jet Propulsion Laboratory (JPL)
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Caldera-like depression on G
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The shallow, scalloped depre
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12/16/00
| Date |
12/16/00 |
| Description |
The shallow, scalloped depression in the center of this picture from NASA's Galileo spacecraft is a caldera-like feature 5 to 20 kilometers (3 to 12 miles) wide on Jupiter's largest moon, Ganymede. Calderas are surface depressions formed by collapse above a subsurface concentration of molten material. Some shallow depressions in bright, smooth areas of Ganymede have some overall similarities to calderas on Earth and on Jupiter's moon Io. On Ganymede, caldera-like depressions may serve as sources of bright, volcanic flows of liquid water and slush, an idea supported by a Ganymede photo obtained by Galileo during its seventh orbit and available at http://photojournal.jpl.nasa.gov/cgi- bin/PIAGenCatalogPage.pl?PIA01614 . In the more recent image here, from Galileo's 28th orbit, a tall scarp marks the western boundary of a caldera-like feature. The western scarp is aligned similarly to older tectonic grooves visible in the image, suggesting the feature has collapsed along older lines of weakness. The interior is mottled in appearance, yet smooth compared to most of Ganymede's bright terrain seen at high resolution. The eastern boundary of the caldera-like feature is cut by younger, grooved terrain. Small impact craters pepper the scene, but the lack of a raised rim argues against an impact origin for the caldera-like feature itself. Instead, water-rich icy lava may have once flowed out of it toward the east. If so, later tectonism could have erased any telltale evidence of volcanic flow fronts. Direct evidence for icy volcanism on Ganymede continues to be elusive. North is to the top of the picture and the Sun illuminates the surface from the left. The image, centered at -24 degrees latitude and 318 degrees longitude, covers an area approximately 162 by 119 kilometers (101 by 74 miles). The resolution is 43 meters (141 feet) per picture element. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by Brown University, Providence, R.I., http://www.planetary.brown.edu/ . # # # # # |
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A More Spectacular Sombrero
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| Title |
A More Spectacular Sombrero (Widescreen Version) |
| Description |
This movie shifts from the well-known visible-light picture of Messier 104 taken by the Hubble Space Telescope to infrared views from NASA's Spitzer Space Telescope. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." Viewed from Earth, the spiral galaxy is seen nearly edge-on, just six degrees away from its equatorial plane. 50,000 light-years across, the Sombrero galaxy is considered one of the most massive objects at the southern edge of the Virgo cluster of galaxies. It is located 28 million light-years away, hosts a rich system of nearly 2,000 globular clusters and may harbor a super-massive black hole. In Hubble's visible light image, only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, pierced through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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Spitzer Spies Spectacular So
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| Title |
Spitzer Spies Spectacular Sombrero |
| Description |
NASA's Spitzer and Hubble Space Telescopes joined forces to create this striking composite image of one of the most popular sights in the universe. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." In Hubble's visible light image (lower left panel), only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera (lower right panel) uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, piercing through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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Spitzer Spies Spectacular So
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| Title |
Spitzer Spies Spectacular Sombrero |
| Description |
NASA's Spitzer and Hubble Space Telescopes joined forces to create this striking composite image of one of the most popular sights in the universe. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." In Hubble's visible light image (lower left panel), only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera (lower right panel) uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, piercing through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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Spitzer Spies Spectacular So
…
| Title |
Spitzer Spies Spectacular Sombrero |
| Description |
NASA's Spitzer and Hubble Space Telescopes joined forces to create this striking composite image of one of the most popular sights in the universe. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." In Hubble's visible light image (lower left panel), only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera (lower right panel) uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, piercing through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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Spitzer Spies Spectacular So
…
| Title |
Spitzer Spies Spectacular Sombrero |
| Description |
NASA's Spitzer and Hubble Space Telescopes joined forces to create this striking composite image of one of the most popular sights in the universe. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." In Hubble's visible light image (lower left panel), only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera (lower right panel) uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, piercing through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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A More Spectacular Sombrero
| Title |
A More Spectacular Sombrero |
| Description |
This movie shifts from the well-known visible-light picture of Messier 104 taken by the Hubble Space Telescope to infrared views from NASA's Spitzer Space Telescope. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer's striking infrared view, the galaxy looks more like a "bull's eye." Viewed from Earth, the spiral galaxy is seen nearly edge-on, just six degrees away from its equatorial plane. 50,000 light-years across, the Sombrero galaxy is considered one of the most massive objects at the southern edge of the Virgo cluster of galaxies. It is located 28 million light-years away, hosts a rich system of nearly 2,000 globular clusters and may harbor a super-massive black hole. In Hubble's visible light image, only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer's infrared array camera uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer's infrared view of the starlight, pierced through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. The Spitzer picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. The Hubble Heritage Team took these observations in May-June 2003 with the space telescope's Advanced Camera for Surveys. Images were taken in three filters (red, green, and blue) to yield a natural-color image. The team took six pictures of the galaxy and then stitched them together to create the final composite image. This magnificent galaxy has a diameter that is nearly one-fifth the diameter of the full Moon. |
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Fire and Ice Planet (without
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| Title |
Fire and Ice Planet (without data plot) |
| Description |
This artist's animation shows a blistering world revolving around its nearby "sun." NASA's infrared Spitzer Space Telescope observed a planetary system like this one, as the planet's sunlit and dark hemispheres swung alternately into the telescope's view. Based on the rise and fall of the planet's infrared light, or heat, Spitzer was able to measure the difference in temperature between the two sides of the planet -- about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to the astronomers, this means that the sunlit side of the planet is always as hot as fire, while the dark side is potentially as cold as ice. The movie illustrates what the system might looks like to infrared eyes. It begins by showing an overhead view of the star Upsilon Andromedae and its planet Upsilon Andromedae b, the closest of three planets orbiting the star and the object of the Spitzer study. This planet whips around its star in 4.6 days. The animation then shifts to show Spitzer's view of the system. The planet is shown with winds that circulate quickly around the surface, though astronomers believe the planet is "tidally locked." Our moon is similarly locked to Earth, always showing us the same face. Spitzer measured the infrared light,coming from both the star and the planet at five points during the planet's orbit. The temperature levels went and up and down depending on which face of the planet, sunlit or dark, was in Spitzer's line of sight. This allowed astronomers to determine the temperature difference between the two hemispheres of the planet. These results indicate that, even if strong winds blow across this planet, its sun-baked atmosphere would cool off before reaching the planet's dark side. |
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Exotic World Blisters Under
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| Title |
Exotic World Blisters Under the Sun |
| Description |
This artist's concept shows a Jupiter-like planet soaking up the scorching rays of its nearby "sun." NASA's Spitzer Space Telescope used its heat-seeking infrared eyes to figure out that a gas-giant planet like the one depicted here is two-faced, with one side perpetually in the cold dark, and the other forever blistering under the heat of its star. The illustration portrays how the planet would appear to infrared eyes, showing temperature variations across its surface. The planet, called Upsilon Andromedae b, was first discovered in 1996 around the star Upsilon Andromedae, located 40 light-years away in the constellation Andromeda. This star also has two other planets orbiting farther out. Upsilon Andromedae b is what's known as a "hot-Jupiter" planet, because it is made of gas like our Jovian giant, and it is hot, due to its tight, 4.6-day-long jaunt around its star. The toasty planet orbits at one-sixth the distance of Mercury from our own sun. It travels in a plane that is seen neither edge- nor face-on from our solar system, but somewhere in between. Scientists do not know how fast Upsilon Andromedae b is spinning on its axis, but they believe that it is tidally locked to its star, just as our locked moon forever hides its "dark side" from Earth's view. Spitzer observed Upsilon Andromedae b at five points during the planet's trip around its star. The planet's light levels went up or down, as detected by Spitzer, depending on whether the planet's sunlit or dark side was pointed toward Earth. These data indicate that the temperature difference between the two hemispheres of the planet is about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to astronomers, this means that the side of the planet that faces the star is always as hot as lava, while the other side could potentially be as cold as ice. Specifically, the hot side of the planet ranges from about 1,400 to 1,650 degrees Celsius (2,550 to 3,000 degrees Fahrenheit), and the cold side from about minus 20 to 230 degrees Celsius (minus 4 to 450 degrees Fahrenheit). How can one side always be hot? The atmosphere of the planet must be absorbing and reradiating light fast enough that any heated gas circulating around the planet is cooled off before it reaches the dark side. |
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Fire and Ice Planet
| Title |
Fire and Ice Planet |
| Description |
This artist's animation shows a blistering world revolving around its nearby "sun." NASA's infrared Spitzer Space Telescope observed a planetary system like this one, as the planet's sunlit and dark hemispheres swung alternately into the telescope's view. Based on the rise and fall of the planet's infrared light, or heat, Spitzer was able to measure the difference in temperature between the two sides of the planet -- about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to the astronomers, this means that the sunlit side of the planet is always as hot as fire, while the dark side is potentially as cold as ice. The movie illustrates what the system might looks like to infrared eyes. It begins by showing an overhead view of the star Upsilon Andromedae and its planet Upsilon Andromedae b, the closest of three planets orbiting the star and the object of the Spitzer study. This planet whips around its star in 4.6 days. The animation then shifts to show Spitzer's view of the system. The planet is shown with winds that circulate quickly around the surface, though astronomers believe the planet is "tidally locked." Our moon is similarly locked to Earth, always showing us the same face. Spitzer measured the infrared light,coming from both the star and the planet at five points during the planet's orbit. The temperature levels went and up and down depending on which face of the planet, sunlit or dark, was in Spitzer's line of sight. The actual data collected by Spitzer are displayed over the animation. The difference between the peak and trough of the green curve represents the difference in temperature across the surface of the planet. These results indicate that, even if strong winds blow across this planet, its sun-baked atmosphere will cool off before reaching the planet's dark side. |
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First Map of Alien World
| Title |
First Map of Alien World |
| Description |
This is the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Hotter temperatures are represented in brighter colors. HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon, or sun-facing, point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it (see animation). By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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First Map of Alien World
| Title |
First Map of Alien World |
| Description |
This is the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Hotter temperatures are represented in brighter colors. HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon, or sun-facing, point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it (see animation). By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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Mapping Exotic Worlds (Wides
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| Title |
Mapping Exotic Worlds (Widescreen Version) |
| Description |
This animation shows the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Everything else shown, for example the star and the lines, are artistic illustrations. The movie begins by showing a two-dimensional view of the map. Hotter temperatures are represented in brighter colors. The map is then shown over the three-dimensional surface of the planet, and the movie spins around, revealing the planet's star. A line projecting from the star to the planet highlights where the planet is directly hit by starlight -- a point known as "high noon." HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at about 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it. By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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Blacker than Black
| Title |
Blacker than Black |
| Description |
This artist's animation illustrates the hottest planet yet observed in the universe. The scorching ball of gas, a "hot Jupiter" called HD 149026b, is a sweltering 3,700 degrees Fahrenheit (2,040 degrees Celsius) -- about three times hotter than the rocky surface of Venus, the hottest planet in our solar system. The planet is so hot that astronomers believe it is absorbing almost all of the heat from its star, and reflecting very little to no light. Objects that reflect no sunlight are black. Consequently, HD 149026b might be the blackest known planet in the universe, in addition to the hottest. The temperature of this dark and balmy planet was taken with NASA's Spitzer Space Telescope. While the planet reflects no visible light, its heat causes it to radiate a little visible and a lot of infrared light. Spitzer, an infrared observatory, was able to measure this infrared light through a technique called secondary eclipse. HD 149026b is what is known as a transiting planet, which means that it crosses in front of and passes behind its star -- the secondary eclipse -- when viewed from Earth. By determining the drop in total infrared light that occurs when the planet disappears, astronomers can figure out how much infrared light is coming from the planet alone. The Spitzer observations of HD 149026b also suggest a hot spot in the middle of the side of the planet that always faces its star. Even though the planet is black, the spot would glow like a black lump of charcoal. HD 149026b is thought to be tidally locked, just as our moon is to Earth, such that one side of the planet is perpetually baked under the heat of its sun. Astronomers think that HD 149026b is probably blazing hot on its sunlit side, and much cooler on its dark side. A similar phenomenon was observed previously by Spitzer for the planet Upsilon Andromedae b. In the case of both planets, heat is not being evenly distributed across their surfaces. This is the opposite of what happens on Jupiter, where temperature differences are minimal all around. HD 149026b is located 256 light-years away in the constellation Hercules. It is the smallest known transiting planet, with a size similar to Saturn's and a suspected dense core 70 to 90 times the mass of Earth. It speeds around its star every 2.9 days. |
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Blacker than Black (Widescre
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| Title |
Blacker than Black (Widescreen Version) |
| Description |
This artist's animation illustrates the hottest planet yet observed in the universe. The scorching ball of gas, a "hot Jupiter" called HD 149026b, is a sweltering 3,700 degrees Fahrenheit (2,040 degrees Celsius) -- about three times hotter than the rocky surface of Venus, the hottest planet in our solar system. The planet is so hot that astronomers believe it is absorbing almost all of the heat from its star, and reflecting very little to no light. Objects that reflect no sunlight are black. Consequently, HD 149026b might be the blackest known planet in the universe, in addition to the hottest. The temperature of this dark and balmy planet was taken with NASA's Spitzer Space Telescope. While the planet reflects no visible light, its heat causes it to radiate a little visible and a lot of infrared light. Spitzer, an infrared observatory, was able to measure this infrared light through a technique called secondary eclipse. HD 149026b is what is known as a transiting planet, which means that it crosses in front of and passes behind its star -- the secondary eclipse -- when viewed from Earth. By determining the drop in total infrared light that occurs when the planet disappears, astronomers can figure out how much infrared light is coming from the planet alone. The Spitzer observations of HD 149026b also suggest a hot spot in the middle of the side of the planet that always faces its star. Even though the planet is black, the spot would glow like a black lump of charcoal. HD 149026b is thought to be tidally locked, just as our moon is to Earth, such that one side of the planet is perpetually baked under the heat of its sun. Astronomers think that HD 149026b is probably blazing hot on its sunlit side, and much cooler on its dark side. A similar phenomenon was observed previously by Spitzer for the planet Upsilon Andromedae b. In the case of both planets, heat is not being evenly distributed across their surfaces. This is the opposite of what happens on Jupiter, where temperature differences are minimal all around. HD 149026b is located 256 light-years away in the constellation Hercules. It is the smallest known transiting planet, with a size similar to Saturn's and a suspected dense core 70 to 90 times the mass of Earth. It speeds around its star every 2.9 days. |
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Artist's Conception of Sedna
| Title |
Artist's Conception of Sedna |
| Description |
In this artist's visualization, the newly discovered planet-like object, dubbed "Sedna," is shown where it resides at the outer edges of the known solar system. The object is so far away that the Sun appears as an extremely bright star instead of the large, warm disc observed from Earth. All that is known about Sedna's appearance is that it has a reddish hue, almost as red and reflective as the planet Mars. In the distance is a hypothetical small moon, which scientists believe may be orbiting this distant body. |
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Mapping Exotic Worlds
| Title |
Mapping Exotic Worlds |
| Description |
This animation shows the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map, which shows temperature variations across the cloudy tops of a gas giant called HD 189733b, is made up of infrared data taken by NASA's Spitzer Space Telescope. Everything else shown, for example the star and the lines, are artistic illustrations. The movie begins by showing a two-dimensional view of the map. Hotter temperatures are represented in brighter colors. The map is then shown over the three-dimensional surface of the planet, and the movie spins around, revealing the planet's star. A line projecting from the star to the planet highlights where the planet is directly hit by starlight -- a point known as "high noon." HD 189733b is what is known as a hot-Jupiter planet. These sizzling, gas planets practically hug their stars, orbiting at distances that are much closer than Mercury is to our sun. They whip around their stars quickly, for example, HD 189733b completes one orbit in just 2.2 days. Hot Jupiters are also thought to be tidally locked to their stars, just as our moon is to Earth. This means that one side of a hot Jupiter always faces its star. As predicted, the map reveals that HD 189733b has a warm spot on its "sunlit" side, which is always pointed toward the star. But the map also shows that this spot is offset from the high-noon point by 30 degrees. According to scientists, ferocious winds traveling up to 6,000 miles per hour (nearly 9,700 kilometers per hour) are probably pushing the hot spot to the east. In addition to the warm spot, the map tells astronomers that temperatures on HD 189733b are fairly even all around. While the dark side is about 1,200 degrees Fahrenheit (650 degrees Celsius), the sunlit side is just a bit hotter at about 1,700 degrees Fahrenheit (930 degrees Celsius). This mild temperature variation is more evidence for strong winds, since winds would help spread the heat from the hot, sunlit side over to the dark side. These data were collected by Spitzer's infrared array camera as the planet, a so-called transiting planet, passed in front of its star, then swung around and disappeared behind it. By observing the planet for half of its 2.2-day long orbit, Spitzer was able to measure the infrared light, or heat, coming from its entire surface. The infrared measurements, about a quarter of a million individual data points, were then assembled by scientists into pole-to-pole strips, and ultimately into the complete map shown here. |
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Blacker than Black
| Title |
Blacker than Black |
| Description |
This artist's concept illustrates the hottest planet yet observed in the universe. The scorching ball of gas, a "hot Jupiter" called HD 149026b, is a sweltering 3,700 degrees Fahrenheit (2,040 degrees Celsius) -- about 3 times hotter than the rocky surface of Venus, the hottest planet in our solar system. The planet is so hot that astronomers believe it is absorbing almost all of the heat from its star, and reflecting very little to no light. Objects that reflect no sunlight are black. Consequently, HD 149026b might be the blackest known planet in the universe, in addition to the hottest. The temperature of this dark and balmy planet was taken with NASA's Spitzer Space Telescope. While the planet reflects no visible light, its heat causes it to radiate a little visible and a lot of infrared light. Spitzer, an infrared observatory, was able to measure this infrared light through a technique called secondary eclipse. HD 149026b is what is known as a transiting planet, which means that it crosses in front of and passes behind its star -- the secondary eclipse -- when viewed from Earth. By determining the drop in total infrared light that occurs when the planet disappears, astronomers can figure out how much infrared light is coming from the planet alone. The Spitzer observations of HD 149026b also suggest a hot spot in the middle of the side of the planet that always faces its star. Even though the planet is black, the spot would glow like a black lump of charcoal. HD 149026b is thought to be tidally locked, just as our moon is to Earth, such that one side of the planet is perpetually baked under the heat of its sun. Astronomers think that HD 149026b is probably blazing hot on its sunlit side, and much cooler on its dark side. A similar phenomenon was observed previously by Spitzer for the planet Upsilon Andromedae b. In the case of both planets, heat is not being evenly distributed across their surfaces. This is the opposite of what happens on Jupiter, where temperature differences are minimal all around. HD 149026b is located 256 light-years away in the constellation Hercules. It is the smallest known transiting planet, with a size similar to Saturn's and a suspected dense core 70 to 90 times the mass of Earth. It speeds around its star every 2.9 days. |
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A Real Shiner
| Description |
A Real Shiner |
| Full Description |
Saturn's moon Rhea shows off the moon equivalent of a black eye -- a bright, rayed crater near its eastern limb. Rhea is about half the size of Earth's moon. At 1,528 kilometers (949 miles) across, it is the second-largest moon orbiting Saturn. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Oct. 24, 2004, at a distance of about 1.7 million kilometers (1 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 40 degrees. The image scale is approximately 10 kilometers (6 miles) per pixel. Cassini will image this hemisphere of Rhea again in mid-January 2005, just after the Huygens probe landing on Titan - with approximately 1-kilometer (0.6-mile) resolution. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . *Image Credit:* NASA/JPL/Space Science Institute |
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The Veils of Titan
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The veils of Saturn's most mysterious moon have begun to lift in Cassini's eagerly awaited first glimpse of the surface of Titan, a world where scientists believe organic matter rains from hazy skies and seas of liquid hydrocarbons dot a frigid surface. Surface features previously observed only from Earth-based telescopes are now visible in images of Titan taken in mid-April by Cassini through one of the narrow angle camera's spectral filters specifically designed to penetrate the thick atmosphere. The image scale is 230 kilometers (143 miles) per pixel, and it rivals the best Earth-based images. The two images displayed here show Titan from a vantage point 17 degrees below its equator, yielding a view from 50 degrees north latitude all the way to its south pole. The image on the left was taken four days after the image on the right. Titan rotated 90 degrees in that time. The two images combined cover a region extending halfway around the moon. The observed brightness variations suggest a diverse surface, with variations in average reflectivity on scales of a couple hundred kilometers. The images were taken through a narrow filter centered at 938 nanometers, a spectral region in which the only obstacle to light is the carbon-based, organic haze. Despite the rather long 38-second exposure times, there is no noticeable smear due to spacecraft motion. The images have been magnified 10 times and enhanced in contrast to bring out details. No further processing to remove the effects of the overlying atmosphere has been performed. The superimposed grid over the images illustrates the orientation of Titan -- north is up and rotated 25 degrees to the left -- as well as the geographical regions of the satellite that are illuminated and visible. The yellow curve marks the position of the boundary between day and night on Titan. The enhanced image contrast makes the region within 20 degrees of this day and night division darker than usual. The Sun illuminates Titan from the right at a phase angle of 66 degrees. Because the Sun is in the southern hemisphere as seen from Titan, the north pole is canted relative to the boundary between day and night by 25 degrees. Also shown here is a map of relative surface brightness variations on Titan as measured in images taken in the 1080-nanometer spectral region in 1997 and 1998 by the Near Infrared Camera and Multi-Object Spectrometer on NASA¿s Hubble Space Telescope. These images have scales of 300 kilometers (186 miles) per pixel. The map colors indicate different surface reflectivities. From darkest to brightest, the color progression is: deep blue (darkest), light blue, green, yellow, red and deep red (brightest). The large, continent-sized, red feature extending from 60 degrees to 150 degrees west longitude is called Xanadu. It is unclear whether Xanadu is a mountain range, giant basin, smooth plain, or a combination of all three. It may be dotted with hydrocarbon lakes but that is also unknown. All that, is presently known is that in Earth-based images, it is the brightest region on Titan. A comparison between the Cassini images and the Hubble map indicates that Xanadu is visible as a bright region in the Cassini image on the right. The dark blue northwest-southeast trending feature from 210 degrees to 250 degrees west longitude, and the bright yellow/green region to the east (right) and southeast of it at minus 50 degrees latitude and 180 to 230 degrees west longitude on the Hubble map, can both be seen in the image on the left. It is noteworthy that the surface is visible to Cassini from its present approach viewing geometry, which is not the most favourable for surface viewing. These early Cassini observations are promising for upcoming imaging sequences of Titan in which the resolution improves by a factor of five over the next two months. These results are encouraging for future, in-orbit observations of Titan that will be acquired from lower, more favorable phase angles. The first opportunity to view small-scale features (2 kilometers or 1.2 miles) on the surface comes during a 350,000 kilometer (217,500 mile) flyby over Titan's south pole on July 2, 2004, only 30 hours after Cassini's insertion into orbit around the ringed planet. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute |
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August 2006: View of the Pla
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| Description |
August 2006: View of the Planets |
| Full Description |
Just before the eastern sky brightens with sunrise, three planets and the waning crescent moon join the starry twilight tapestry. Then, as the bright stars of Gemini and Orion fade with oncoming dawn, the planets rise and shine. About 45 minutes before sunrise on Aug. 20 to 22 the planets Venus, Mercury and Saturn dance on the ecliptic -- the plane of Earth's orbit and the imaginary line tracing it in the sky. The sun, moon and planets appear to move along this line. Venus, rising an hour and a half before sunrise, is the easiest to see in the morning sky. Two hundred forty-one million kilometers (150 million miles) distant, Venus is Earth-sized. Mercury, at a distance of 183 million kilometers (114 million miles), is the fastest and smallest of the inner planets and appears brighter than the more distant Saturn. Saturn, 1,517 million kilometers (943 million miles) distant, was at conjunction with the sun just two weeks ago and now rises nearly an hour before sunrise. On Aug. 26 and 27, Saturn pairs with much brighter Venus at dawn. What other planets can we see in late August? Mars sets 45 minutes after sunset by month's end but is lost from view in the twilight, while brilliant Jupiter remains prominent as the only planet visible for a few hours during the late August evenings. Credit: NASA/JPL |
| Date |
August 18, 2006 |
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Pale Blue Orb (1)
| Description |
Pale Blue Orb |
| Full Description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus, for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is 129 kilometers (80 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov ., The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
September 19, 2006 |
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In Saturn's Shadow (Color-ex
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| Description |
In Saturn's Shadow (Color-exagerated view) |
| Full Description |
+ Original version + Image with labels With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the, images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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Moons in the Night
| Description |
Moons in the Night |
| Full Description |
Sunlight makes visible the faint band called the E ring as two moons meet in the sky. Enceladus (505 kilometers, or 314 miles across) and Tethys (1,071 kilometers, or 665 miles across) appear close together in the sky in this image, but in reality, Tethys was more than 260,000 kilometers (162,000 miles) farther from the Cassini spacecraft -- greater than half the distance from Earth to the Moon. Enceladus is easy to identify by the brilliant plume of ice erupting from its south pole. Although this perspective views the night sides of both moons, the Sun is not the only source of illumination in the Saturn system. Tethys is at a fuller phase with respect to Saturn, and thus its "night side" is more fully lit than that of Enceladus. The view was acquired from a Sun-Enceladus-spacecraft, or phase, angle of 163 degrees, a viewing geometry in which the microscopic ice particles in its plume brighten substantially. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 6, 2006 at a distance of approximately 3.9 million kilometers (2.4 million miles) from Enceladus and 4.2 million kilometers (2.6 million miles) from Tethys. Image scale is 23 kilometers (14 miles) per pixel on Enceladus and 25 kilometers (16 miles) on Tethys. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
April 16, 2007 |
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Cat's eye rings and peek-a-b
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| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line crossing obliquely behind the A ring is, caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the University of Arizona, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
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Cat's eye rings and peek-a-b
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| Description |
On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. |
| Full Description |
See also the non-annotated version. Astronomers have long known that Saturn's rings reflect sunlight most strongly when Earth is located directly between Saturn and the sun. Flat, shiny surfaces (like a mirror or a pond) can appear particularly bright when light reflects off them in a certain direction. Scientists call this "specular reflection," from the Latin word for mirror. However, even rough surfaces, like those of Earth's moon or Saturn's rings, can appear bright when the source of light is directly behind the observer's head, no matter what the orientation of the surface is. This latter phenomenon is known as the "opposition effect." Spectacular examples include the eyes of a cat, which seem to glow brightly when they are illuminated by a flashlight, or highway signs and reflectors that "light up" when they are caught in a car's headlights. On Aug. 16, 2006, as the Cassini orbiter flew directly between the sun and Saturn, its Visual and Infrared Mapping Spectrometer captured a sequence of images that vividly show this opposition brightening. Combined here into a mosaic, the images show -- from left to right -- a small, bright spot moving from the outermost B ring across the Cassini Division and all the way across the A ring. In each image, this spot is centered on the point in the rings directly opposite the sun. Theoretical models for the opposition effect suggest that it can be explained by light being scattered several times within the surfaces of individual, transparent, icy ring particles on scales of about 40 micrometers, or 1/500th of an inch. Similar effects are seen in laboratory studies of bright, finely-textured material such as snow or sugar crystals. In this mosaic, blue colors highlight the icy rings (2.35 microns), green represents sunlight reflected by the clouds of Saturn (2.86 microns) and red depicts thermal emission from the planet's interior (5.02 microns). The rings were observed while they were in front of the planet, producing a complex interplay of sunlight reflected from the rings and the shadows cast by the rings on the cloud tops of Saturn. The yellow-green sunlit clouds of Saturn are seen in the upper right corner of the mosaic beyond the outer edge of the A ring, and also through the 4,000-kilometer-wide (2,400 mile) Cassini Division in the left third of the mosaic. (Yellow indicates a mixture of reflected sunlight and thermal emission.) The shadowed regions of the planet, on the other hand, appear deep red because only thermal emission produced deep inside Saturn itself is visible. At exact opposition, the shadows of the rings are hidden behind the rings themselves, but away from this point shadows can be seen peeking out from behind the edges of the A and B rings into the Cassini Division, as well as beyond the outer edge of the A ring. If one looks closely, one can even trace the A ring's shadow behind the partly transparent A ring, as a faint purple band. Within this band, a thin blue-green line, crossing obliquely behind the A ring is caused by sunlight passing through the narrow Encke Gap in the outer A ring. The Cassini spacecraft was at a distance of 254,000 kilometers (157,800 miles) from the center of Saturn when these images were taken, while the opening angle of the rings to the sun was 16.3 degrees. The image scale at the rings is approximately 70 kilometers (40 miles) per pixel. All nine images were taken over a period of 27 minutes, and the vertical dimension of the mosaic is 1.8 degrees. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the University of Arizona, where this image was produced. For more information about the Cassini-Huygens mission, visit: http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping spectrometer team home page is at: http://wwwvims.lpl.arizona.edu . Credit: NASA/JPL/University of Arizona |
| Date |
June 26, 2007 |
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Rhea in Saturnshine
| Description |
Rhea in Saturnshine |
| Full Description |
The night side of Rhea shines softly in reflected light from Saturn. A similar effect, called Earthshine, can often be seen dimly illuminating the dark side Earth's moon. Background stars make short, dim trails across the black sky. The sunlit terrain on Rhea is so much brighter than the part lit by Saturn that the former is completely overexposed in this view, which took more than 30 seconds to acquire. This view looks toward the leading hemisphere on Rhea (1,528 kilometers, or 949 miles across). North is up and rotated 28 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 11, 2007. The view was obtained at a distance of approximately 364,000 kilometers (226,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 154 degrees. Image scale is 4 kilometers (3 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
July 18, 2007 |
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Bands of Clouds and Lace
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
As Cassini nears its rendezvous with Saturn, new detail in the banded clouds of the planet's atmosphere are becoming visible. Cassini began the journey to the ringed world of Saturn nearly seven years ago and is now less than two months away from orbit insertion on June 30. Cassini¿s narrow-angle camera took this image on April 16, 2004, when the spacecraft was 38.5 million kilometers (23.9 million miles) from Saturn. Dark regions are generally areas free of high clouds, and bright areas are places with high, thick clouds which shield the view of the darker areas below. A dark spot is visible at the south pole, which is remarkable to scientists because it is so small and centered. The spot could be affected by Saturn's magnetic field, which is nearly aligned with the planet's rotation axis, unlike the magnetic fields of Jupiter and Earth. From south to north, other notable features are the two white spots just above the dark spot toward the right, and the large dark oblong-shaped feature that extends across the middle. The darker band beneath the oblong-shaped feature has begun to show a lacy pattern of lighter-colored, high altitude clouds, indicative of turbulent atmospheric conditions. The cloud bands move at different speeds, and their irregularities may be due to either the different motions between them or to disturbances below the visible cloud layer. Such disturbances might be powered by the planet's internal heat, Saturn radiates more energy than it receives from the Sun. The moon Mimas (396 kilometers, 245 miles across) is visible to the left of the south pole. Saturn currently has 31 known moons. Since launch, 13 new moons have been discovered by ground-based telescopes. Cassini will get a closer look and may discover new moons, perhaps embedded within the planet¿s magnificent rings. This image was taken using a filter sensitive to light near 727 nanometers, one of the near-infrared absorption bands of methane gas, which is one of the ingredients in Saturn's atmosphere. The image scale is approximately 231 kilometers (144 miles) per pixel. Contrast has been enhanced to aid visibility of features in the atmosphere. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. *Image Note: * * Credit: NASA/JPL/Southwest Research Institute For higher resolution, click here. |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Jupiter's Magnetosphere Made Visible February 27, 2002 The vast magnetosphere of charged particles whirling around Jupiter, normally invisible, can be imaged by a new type of instrument aboard NASA's Cassini spacecraft and is seen here. Three features are sketched in for context: a black circle showing the size of Jupiter, lines of Jupiter's magnetic field, and a cross-section of the Io torus, a doughnut-shaped ring of charged particles that originate from volcanic eruptions on Jupiter's moon Io and circle Jupiter at about the orbit of Io. Jupiter's magnetosphere is the largest object in the solar system. If it glowed in wavelengths visible to the eye, it would appear two to three times the size of the Sun or Moon to viewers on Earth. Cassini's ion and neutral camera detects neutral atoms expelled from the magnetosphere, deriving information about their source. This image was taken shortly after Cassini's closest approach to Jupiter, about 10 million kilometers (6 million miles) from the planet on Dec. 30, 2000. For more information about the Saturn-bound spacecraft and its observations of Jupiter, see the Cassini home page, http://saturn.jpl.nasa.gov. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. Credit: NASA/JPL/Johns Hopkins University Applied Physics Laboratory More information about the Cassini and Galileo joint observations of the Jupiter system is available online at: http://www.jpl.nasa.gov/jupiterflyby. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Cassini missions for NASA's Office of Space Science, Washington, D.C. For higher resolution, click here. |
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Rhea's Memory
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Saturn's icy moon Rhea |
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The story of the solar system is written upon the faces of its many worlds, such as Saturn's icy moon Rhea, seen here in an image from Cassini. The moon's many impact craters attest to its violent beginnings and more than four billion years of subsequent history. Rhea is 1,528 kilometers (949 miles) across. Most moons in the outer solar system are icy, in contrast to the rocky inner planets and Earth's moon. When the planets and their moons first formed around our Sun, conditions were cold enough at Saturn's distance that ices could condense to form solid bodies like Rhea. Since its formation, Rhea has been battered by the leftover debris of planet building, although at a much lower rate for the past 3.8 billion years or so. North on Rhea is up and rotated about 20 degrees to the left. This view shows principally the leading hemisphere on Rhea. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 5, 2005, at a distance of approximately 1.4 million kilometers (900,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 78 degrees. The image scale is 9 kilometers (6 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
June 23, 2005 |
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Rings At Opposition
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Rings At Opposition |
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When Cassini gazes down at Saturn's rings with the Sun directly behind the spacecraft, an unusual phenomenon called the "opposition effect" can be seen. The effect is visible here as a bright region, near right, toward the inner edge of the A ring. The precise nature of the effect at Saturn is still under scrutiny by imaging scientists. However the effect in Saturn's rings can be witnessed from Earth, when the viewing conditions are right. It can also be seen in photographs of the lunar surface taken by the Apollo astronauts. To understand the effect, imagine an observer standing on a dry, sandy beach. When the Sun is directly behind the observer, the shadows cast by the grains in the field of view in front of the observer will fall directly behind the grains and will not be visible. When the Sun is at any other angle relative to the observer, the shadows cast by the grains will be visible to the observer. These shadows in the field of view make the scene a bit darker. This effect would cause a centrally bright spot to appear on the sandy surface in the first case, but not in the second. For Cassini, the opposition effect is seen when the angle between the Sun, the rings and the spacecraft is extremely close to zero. For the sequence of images during which this view was obtained, Cassini maintained this viewing angle and the bright spot appeared to move across the rings with the spacecraft's motion. The moon Janus (181 kilometers, or 113 miles, across) is seen here at lower left. The image was taken in visible light with the Cassini spacecraft wide-angle camera on June 7, 2005, at a distance of approximately 738,000 kilometers (458,000 miles) from Saturn. The image scale is 40 kilometers (25 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org. Credit: NASA/JPL/Space Science Institute |
| Date |
July 15, 2005 |
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Enceladus Temperature Map
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Enceladus Temperature Map |
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This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is, http://cirs.gsfc.nasa.gov/ . Credit: NASA/JPL/GSFC |
| Date |
July 29, 2005 |
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Phoebe Temperature Maps
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Phoebe Temperature Maps |
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A montage of maps of Saturn's moon Phoebe shows surface temperatures at various times of day as determined by the composite infrared spectrometer onboard Cassini during the June 11, 2004, Phoebe flyby. The asterisk on each map shows the location of the subsolar point, where the Sun is directly overhead. This point moves across the surface as Phoebe rotates. It is morning in regions to the left of the subsolar point, and afternoon in regions to the right. Like a newspaper weather map, different colors indicate different temperatures, though Phoebe's temperatures are distinctly cooler than even the coldest January day on Earth. Equatorial temperatures peak in the early afternoon near 112 Kelvin (-257 Fahrenheit), plunging to 78 Kelvin (-319 Fahrenheit) before dawn, and are even colder at higher latitudes. The large day/night temperature contrasts imply that Phoebe's surface is covered in loose dust or ice particles that store little heat and thus cool off rapidly at night. Regions of Phoebe's surface that were not observed are shown in black. Most of the maps show the effect on surface temperatures of the large crater-like depression seen in Cassini's visible-wavelength images of Phoebe, which is located just left of center in these maps. Crater walls that are shadowed and cold in the early morning in the first map are sunlit and warm in the late afternoon in the final map. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini composite infrared spectrometer home page at http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/Goddard Space Flight Center |
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Faint Southern Clouds
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Faint Southern Clouds |
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This clear-filter view of Saturn's moon Titan reveals a region of cloud activity at high southern latitudes. Titan is 5,150 kilometers (3,200 miles) across. Cassini observations have generally been consistent with Earth-based observations that indicate the south-polar fields of clouds that had been observed frequently in 2004 haven't been present in 2005. This image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 31, 2005, at a distance of approximately 3.3 million kilometers (2 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 70 degrees. The image scale is 20 kilometers (12 miles) per pixel. North on Titan is up and rotated about 20 degrees to the left. The view has been mildly enhanced to make the cloud feature more easily visible. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
September 29, 2005 |
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3D Movie of Saturn's Rings D
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Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
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This 3D movie was made from a sequence of images taken by NASA's Cassini spacecraft as it crossed the plane of Saturn's main rings. The main rings are nearly as broad from edge to edge as the distance from the Earth to the moon but are only a few tens of meters thick -- like a piece of paper the size of Golden Gate Park. Scientists have struggled for centuries to measure their thickness from Earth, without success. The ring particles are centimeters to meters in size, and their gentle collisions keep the rings so strongly flattened. Note the dramatic change in the appearance of the rings as the ring plane is crossed. Regions containing many particles are opaque (the B ring), so are bright on the sunlit side and dark on the side facing away from the sun. Regions containing only a few particles (the C ring and Cassini Division) appear bright from both the lit and unlit sides. Credit: Scott Sandford, Astrophysics Branch, NASA-Ames Research Center |
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Mimas...and Titan Beyond
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Mimas...and Titan Beyond |
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Titan, Saturn's largest moon, and Mimas, closer but much smaller on the right, are seen together in this view from Cassini. Titan's gravity is weaker than Earth's, so the moon's atmosphere is quite extended -- a quality hinted at in this view. Part of Mimas' dark side is illuminated by reflected light from nearby Saturn. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2005, at a distance of approximately 3.6 million kilometers (2.2 million miles) from Titan (5,150 kilometers, or 3,200 miles across) and 2.5 million kilometers (1.6 million miles) from Mimas (397 kilometers, or 247 miles across). Both moons are seen at a Sun-moon-spacecraft angle, or phase angle, of 110 degrees. The image scale is 22 kilometers (14 miles) per pixel on Titan and 15 kilometers (9 miles) per pixel on Mimas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
January 3, 2006 |
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In Saturn's Shadow (with lab
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In Saturn's Shadow (with labels) |
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+ Original version + Color-exagerated version With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when, the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
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Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Cassini mission for NASA's Office of Space Science, Washington, D.C. Credit: NASA/JPL/University of Arizona (PIA02826) For higher resolution, click here., These two images, taken by NASA's Cassini spacecraft, show Jupiter in a near-infrared wavelength, and catch Europa, one of Jupiter's largest moons, at different phases. Cassini's narrow-angle camera took both images, the upper one from a distance of 69.9 million kilometers (43.4 million miles) on Oct. 17, 2000, and the lower one from a distance of 65.1 million kilometers (40.4 million miles) on Oct. 22, 2000. Both were taken at a wavelength of 727 nanometers, which is in the near-infrared region of the electromagnetic spectrum. The camera's 727-nanometer filter accepts only a narrow spectral range centered on a relatively strong absorption feature due to methane gas. In this spectral region, the amount of light reflected by Jupiter's clouds is only half that reflected in a nearby spectral region outside the methane band. The features that are brightest in these images are the highest and thickest clouds, such as the Great Red Spot and the band of clouds girding the equator, as these scatter sunlight back to space before it has a chance to be absorbed by the methane gas in the atmosphere. This stratigraphic effect can be seen even more prominently in an image released on Oct. 23, 2000, taken in the stronger methane band at 889 nanometers, in which the only bright features are the highest hazes over the equator, the poles and the Great Red Spot. By comparing images taken in the 727 nanometer filter with others taken at 889 nanometers and at a weaker methane band at 619 nanometers, researchers will probe the heights and thickness of clouds in Jupiter's atmosphere. Europa, a satellite of Jupiter about the size of Earth's Moon, is visible to the left of Jupiter in the upper image, and in front of the planet in the lower image. Another of Jupiter's Galilean satellites, Ganymede, which is larger than the planet Mercury, is to the right in the upper image, with brightness variations visible across its surface. In the upper image, Europa is caught entering Jupiter's shadow, and hence appears as a bright crescent, in the lower image, it is seen about one-and-a-half orbits later, in transit across the face of the planet. Because there is neither methane nor any strong absorber in this spectral region on the surface of Europa, it appears strikingly white and bright compared to Jupiter. Imaging observations of the moons Europa, Io and Ganymede entering and passing through Jupiter's shadow are planned for the two-week period surrounding Cassini's closest approach on Dec. 30, 2000. The purpose of these eclipse observations is to detect and measure the variability of emissions that arise from the interaction of the satellites' tenuous atmospheres with the charged particles trapped in Jupiter's magnetic field. At the times these images were taken, Cassini was about 3.3 degrees above Jupiter's equatorial plane, and the Sun-Jupiter-spacecraft angle was about 20 degrees. Cassini is a cooperative project of NASA, the European Space Agency and the Italian |
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Influence of Mimas
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Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
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Mimas, seen here beyond Saturn's rings, is a major sculptor of Saturn's rings. The 398-kilometer-wide (247-mile-wide) moon not only maintains the Cassini Division (not seen here), a gap wide enough to be visible from Earth through a small telescope, but it is also responsible for two of the thin, bright bands visible in this image near the rings' center, interior to the dark Encke Gap. Knots in the thin, twisted F ring also are easily visible here. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Sept. 7, 2004, at a distance of 8.8 million kilometers (5.5 million miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 84 degrees. The image scale is 53 kilometers (33 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . *Image Credit:* NASA/JPL/Space Science Institute |
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10,000 Galaxies
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10,000 Galaxies |
| date |
01.16.2004 |
| description |
Galaxies, galaxies everywhere - as far as NASA's Hubble Space Telescope can see. This view of nearly 10,000 galaxies is the deepest visible-light image of the cosmos. Called the Hubble Ultra Deep Field, this galaxy-studded view represents a "deep" core sample of the universe, cutting across billions of light-years. The snapshot includes galaxies of various ages, sizes, shapes, and colors. The smallest, reddest galaxies, about 100, may be among the most distant known, existing when the universe was just 800 million years old. The nearest galaxies - the larger, brighter, well-defined spirals and ellipticals - thrived about 1 billion years ago, when the cosmos was 13 billion years old. In vibrant contrast to the rich harvest of classic spiral and elliptical galaxies, there is a zoo of oddball galaxies littering the field. Some look like toothpicks, others like links on a bracelet. A few appear to be interacting. These oddball galaxies chronicle a period when the universe was younger and more chaotic. Order and structure were just beginning to emerge. The Ultra Deep Field observations, taken by the Advanced Camera for Surveys, represent a narrow, deep view of the cosmos. Peering into the Ultra Deep Field is like looking through an eight-foot-long soda straw. In ground-based photographs, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full Moon) is largely empty. Located in the constellation Fornax, the region is so empty that only a handful of stars within the Milky Way galaxy can be seen in the image. In this image, blue and green correspond to colors that can be seen by the human eye, such as hot, young, blue stars and the glow of Sun-like stars in the disks of galaxies. Red represents near-infrared light, which is invisible to the human eye, such as the red glow of dust-enshrouded galaxies. The image required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days, taken between Sept. 24, 2003 and Jan. 16, 2004. *Image Credit*: NASA, ESA, S. Beckwith (STScI) and the HUDF Team |
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The Plane of the Ecliptic
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The Plane of the Ecliptic |
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The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury. The ecliptic plane is defined as the imaginary plane containing the Earth's orbit around the Sun. In the course of a year, the Sun's apparent path through the sky lies in this plane. The planetary bodies of our solar system all tend to lie near this plane, since they were formed from the Sun's spinning, flattened, proto-planetary disk. The snapshot above nicely captures a momentary line-up looking out along this fundamental plane of our solar system. *Image Credit*: NASA |
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A Piece of the Asteroid Vest
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A Piece of the Asteroid Vesta |
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This meteorite is a sample of the crust of the asteroid Vesta, which is only the third solar system object beyond Earth where scientists have a laboratory sample (the other extraterrestrial samples are from Mars and the Moon). The meteorite is unique because it is made almost entirely of the mineral pyroxene, common in lava flows. The meteorite's mineral grain structure also indicates it was once molten, and its oxygen isotopes are unlike oxygen isotopes found for all other rocks of the Earth and Moon. The meteorite's chemical identity points to the asteroid Vesta because it has the same unique spectral signature of the mineral pyroxene. The meteorite also has the same pyroxene signature as other small asteroids, recently discovered near Vesta, that are considered "chips" blasted off Vesta's surface. This debris extends all the way to an "escape hatch" region in the asteroid belt called the Kirkwood gap. This region is swept free of asteroids because Jupiter's gravitational pull removes material from the main belt and hurls it onto a new orbit that crosses Earth's path around the Sun. The meteorite probably followed this route to Earth. It was torn off Vesta's surface as part of a larger fragment. Subsequent collisions broke apart the parent fragment and threw pieces toward the Kirkwood gap and onto a collision course toward Earth. The fragment's journey ended in 1960 when it fell in Western Australia. NASA's Hubble Space Telescope observations further confirm this scenario by revealing a giant impact basin on the 325-mile (525 km) diameter asteroid. The ancient impact was so powerful, it tore off a piece of the asteroid's crust, exposing a deeper mantle of rock. Most of the identified meteorites from Vesta are in the care of the Western Australian Museum. This 1.4 pound (631 gm) specimen comes from the New England Meteoritical Services. It is a complete specimen measuring 3.7 inch x 3.1 inch x 3.4 inch (9.6 cm x 8.1 cm x 8.7 cm) showing the fusion crust, evidence of the last stage in its journey to Earth. *Image Credit*: R. Kempton (New England Meteoritical Services) |
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Pale Blue Orb (2)
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Pale Blue Orb (2) |
| date |
09.15.2006 |
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Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image, with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus [ http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276 ], for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is approximately 250 kilometers (155 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For, more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ] . Credit: NASA/JPL/Space Science Institute |
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Charon Discovery Image
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Charon Discovery Image |
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06.22.1978 |
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On 22 June 1978, an astronomer at the U.S. Naval Observatory in Washington, D.C. was making routine measurements of photographic plates taken with the 1.55-meter (61-inch) Kaj Strand Astrometric Reflector at the USNO Flagstaff Station in Arizona. The purpose of these images was to refine the orbit of the far-flung planet Pluto to help compute a better ephemeris for this distant object. Astronomer James W. Christy had noticed that a number of the images of Pluto appeared elongated, but images of background stars on the same plate did not. Other plates showed the planet as a tiny, round dot. Christy examined a number of Pluto images from the USNO archives, and he noticed the elongations again. Furthermore, the elongations appeared to change position with respect to the stars over time. After eliminating the possibility that the elongations were produced by plate defects and background stars, the only plausible explanation was that they were caused by a previously unknown moon orbiting Pluto at a distance of about 19,600 kilometers (12,100 miles) with a period of just over six days. On 7 July 1978, the discovery was formally announced to the astronomical community and the world by the IAU Central Bureau for Astronomical Telegrams via IAU Circular 3241. The discovery received the provisional designation "1978 P 1", Christy proposed the name "Charon", after the mythological ferryman who carried souls across the river Acheron, one of the five mythical rivers that surrounded Pluto's underworld. Over the course of the next several years, another USNO astronomer, the late Robert S. Harrington, calculated that Pluto and its newly-found moon would undergo a series of mutual eclipses and occultations, beginning in early 1985. On 17 February 1985 the first successful observation of one of these transits was made at with the 0.9-meter (36-inch) reflector at the University of Texas McDonald Observatory, within 40 minutes of Harrington's predicted time. The IAU Circular announcing these confirming observations was issued on 22 February 1985. With this confirmation, the new moon was officially named Charon. Pluto was discovered at Lowell Observatory in 1930 by the late Clyde W. Tombaugh, an amateur astronomer from Kansas who was hired by the Observatory specifically to photograph the sky with a special camera and search for the planet predicted by the Observatory's founder, Percival Lowell. Lowell had deduced the existence of a "Planet X" by studying small anomalies in the orbits of Uranus and Neptune. As it turned out, Pluto's discovery was almost entirely serendipitous, Pluto's tiny mass was far too small to account for the anomalies, which were resolved when Voyager 2 determined more precise masses for Uranus and Neptune. The discovery of Charon has led to a much better understanding of just how tiny Pluto is. Its diameter is about 2274 km (1413 miles), and its mass is 0.25% of the mass of the Earth. Charon has a diameter of about 1172 kilometers (728, miles) and a mass of about 22% that of Pluto. The two worlds circle their common center of mass with a period of 6.387 days and are locked in a "super-synchronous" rotation: observers on Pluto's surface would always see Charon in the same part of the sky relative to their local horizon. Normally Pluto is considered the most distant world in the solar system, but during the period from January 1979 until February 1999 it was actually closer to the Sun than Neptune. It has the most eccentric and inclinced orbit of any of the major planets. This orbit won't bring Pluto back to its discovery position until the year 2178! *Image Credit*: U.S. Naval Observatory |
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Clementine Observes the Moon
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Clementine Observes the Moon, Solar Corona, and Venus |
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In 1994, during its flight, the Clementine spacecraft returned images of the Moon. In addition to the geologic mapping cameras, the Clementine spacecraft also carried two Star Tracker cameras for navigation. These lightweight (0.3 kg) cameras kept the spacecraft on track by constantly observing the positions of stars, reminiscent of the age-old seafaring tradition of sextant/star navigation. These navigation cameras were also to take some spectacular wide angle images of the Moon. In this picture the Moon is seen illuminated solely by light reflected from the Earth--Earthshine! The bright glow on the lunar horizon is caused by light from the solar corona, the sun is just behind the lunar limb. Caught in this image is the planet Venus at the top of the frame. *Image Credit*: NASA |
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Pluto and Charon
| title |
Pluto and Charon |
| date |
02.21.1994 |
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This is the clearest view yet of the distant planet Pluto and its moon, Charon, as revealed by NASA's Hubble Space Telescope (HST). The image was taken by the European Space Agency's Faint Object Camera on February 21, 1994 when the planet was 4.4 billion kilometers (2.6 billion miles) from Earth, or nearly 30 times the separation between Earth and the Sun. Hubble's corrected optics show the two objects as clearly separate and sharp disks. This now allows astronomers to measure directly (to within about 1 percent) Pluto's diameter of 1440 miles (2320 kilometers) and Charon's diameter of 790 miles (1270 kilometers). The Hubble observations show that Charon is bluer than Pluto. This means that both worlds have different surface composition and structure. A bright highlight on Pluto suggests it has a smoothly reflecting surface layer. A detailed analysis of the Hubble image also suggests there is a bright area parallel to the equator on Pluto. This result is consistent with surface brightness models based on previous ground-based photometric observations. However, subsequent HST observations will be required to confirm whether the feature is real. Though Pluto was discovered in 1930, Charon wasn't detected until 1978. That is because the moon is so close to Pluto that the two worlds are typically blurred together when viewed through ground-based telescopes. (If our moon were as close to Earth, it would be as big in the night sky as an apple held at arm's length). The new HST image was taken when Charon was near its maximum elongation from Pluto of .9 arc seconds. The two worlds are 12,200 miles apart (19,640 kilometers). Hubble's ability to distinguish Pluto's disk at a distance of 2.6 billion miles (4.4 billion kilometers) is equivalent to seeing a baseball at a distance of 40 miles (64 kilometers). Pluto typically is called the double planet because Charon is half the diameter of Pluto (our Moon is one-quarter the diameter of Earth). *Image Credit*: Dr. R. Albrecht, ESA/ESO Space Telescope European Coordinating Facility, NASA |
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Mercury's South Pole
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Mercury's South Pole |
| date |
09.21.1974 |
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Mercury's south pole was photographed by one of Mariner 10's TV cameras as the spacecraft made its second close flyby of the planet September 21. The pole is located inside the large crater (180 kilometers, 110 miles) on Mercury's limb (lower center). The crater floor is shadowed and its far rim, illuminated by the sun, appears to de disconnected from the edge of the planet. Just above and to the right of the South Pole is a double ring basin about 100 kilometers (125 miles) in diameter. A bright ray system, splashed out of a 50 kilometer (30 mile) crater is seen at upper right. The stripe across the top is an artifact introduced during computer processing. The picture (FDS 166902) was taken from a distance of 85,800 kilometers (53,200 miles) less than two hours after Mariner 10 reached its closest point to the planet. The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon. *Image Credit*: NASA/JPL/Northwestern University |
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Change of Seasons on Saturn
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Change of Seasons on Saturn |
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Looming like a giant flying saucer in our outer solar system, Saturn puts on a show as the planet and its magnificent ring system nod majestically over the course of its 29-year journey around the Sun. A series of Hubble Space Telescope images, captured from 1996 to 2000, show Saturn's rings open up from just past edge-on to nearly fully open as it moves from autumn towards winter in its Northern Hemisphere. Saturn's equator is tilted relative to its orbit by 27 degrees, very similar to the 23-degree tilt of the Earth. As Saturn moves along its orbit, first one hemisphere, then the other is tilted towards the Sun. This cyclical change causes seasons on Saturn, just as the changing orientation of Earth's tilt causes seasons on our planet. Saturn's rings are incredibly thin, with a thickness of only about 30 feet (10 meters). The rings are made of dusty water ice, in the form of boulder-sized and smaller chunks that gently collide with each other as they orbit around Saturn. Saturn's gravitational field constantly disrupts these ice chunks, keeping them spread out and preventing them from combining to form a moon. The rings, as shown here, have a slight pale reddish color due to the presence of organic material mixed with the water ice. Saturn is about 75,000 miles (120,000 km) across, and is flattened at the poles because of its very rapid rotation. A day is only 10 hours long on Saturn. Strong winds account for the horizontal bands in the atmosphere of this giant gas planet. The delicate color variations in the clouds are due to smog in the upper atmosphere, produced when ultraviolet radiation from the Sun shines on methane gas. Deeper in the atmosphere, the visible clouds and gases merge gradually into hotter and denser gases, with no solid surface for visiting spacecraft to land on. *Image Credit*: NASA and The Hubble Heritage Team (STScI/AURA). Acknowledgment: R.G. French (Wellesley College), J. Cuzzi (NASA/Ames), L. Dones (SwRI), and J. Lissauer (NASA/Ames) |
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Distant Saturn
| title |
Distant Saturn |
| date |
10.21.2002 |
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Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. *Image Credit*: NASA/JPL/Southwest Research Institute |
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