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Earth and Jupiter of Jet Propulsion Laboratory (JPL)
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Stardust Trajectory
Stardust, a spacecraft desig
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11/22/95
| Date |
11/22/95 |
| Description |
Stardust, a spacecraft designed to gather samples of dust spewed from a comet and return the dust to Earth for detailed analysis, has been selected to become the fourth flight mission in NASA's Discovery program. The spacecraft, to be launched in February 1999, will also gather and return samples of interstellar dust encountered during its trip through the solar system to fly by Comet Wild-2 in January 2004. Comet Wild-2 is a "fresh comet" because its orbit was deflected from much farther out in the solar system by the gravitational attraction of Jupiter in 1974. Stardust will approach as close as 100 kilometers (62 miles) to the comet's nucleus, capturing cometary samples with an unusual material called aerogel. A return capsule carrying the captured dust samples would parachute to Earth in a landing on a dry Utah lake bed in January 2006. Stardust will also carry an optical camera that should return cometary images with 10 times the clarity of those taken of Halley's Comet by previous space missions. A mass spectrometer provided by Germany also will perform compositional analysis of the samples while in-flight. The Stardust mission team will be led by Principal Investigator Dr. Donald Brownlee of the University of Washington in Seattle, with Lockheed-Martin Astronautics, Denver, as the contractor building the spacecraft. NASA's Jet Propulsion Laboratory, Pasadena, CA, will manage the project for NASA's Office of Space Science, Washington, D.C. ##### |
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The Saturn-bound Cassini spa
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8/16/99
| Date |
8/16/99 |
| Description |
The Saturn-bound Cassini spacecraft will fly past the Earth Tuesday, August 17, at 8:28 p.m. Pacific Daylight Time (August 18 at 03:28 Universal Time). Launched in October 1997, Cassini will gain a boost in speed during its Earth flyby, which occurs at an altitude of 1,166 kilometers (725 miles) over the eastern South Pacific at -23.5 degrees latitude and 231.5 degrees longitude. Two successful flybys of Venus, next week's flyby of Earth, and a flyby of Jupiter in December 2000 all give Cassini the additional speed it needs to reach Saturn in 2004. Cassini is a joint endeavor of NASA, the European Space Agency and the Italian Space Agency, and is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory (JPL). JPL is a division of the California Institute of Technology, Pasadena, Calif. [Image for NASA-JPL was created by John Aiello of JPL.] |
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GLL/EM15
This mosaic picture of the M
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12/22/92
| Date |
12/22/92 |
| Description |
This mosaic picture of the Moon was compiled from 18 images taken with a green filter by Galileo's imaging system during the spacecraft's flyby on December 7, 1992, some 11 hours before its Earth flyby at 1509 UTC (7:09 a.m. Pacific Standard Time) December 8. The north polar region is near the top part of the mosaic, which also shows Mare Imbrium, the dark area on the left, Mare Serenitatis at center, and Mare Crisium, the circular dark area to the right. Bright crater rim and ray deposits are from Copernicus, an impact crater 96 kilometers (60 miles) in diameter. Computer processing has exaggerated the brightness of poorly illuminated features near the day/night terminator in the polar regions, giving a false impression of high reflectivity there. The digital image processing was done by DLR the German aerospace research establishment near Munich, an international collaborator in the Galileo mission. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory. ##### |
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GLL/EM16
This view looking down on th
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| Description |
This view looking down on the north pole of the Moon was assembled from 18 images taken with a green filter by Galileo's imaging system as the spacecraft flew by the Moon on December 7, 1992. The part of the moon visible from Earth is toward the left and includes the dark, lava-filled Imbrium basin, upper left, Mare Serenitatis, middle left, Mare Tranquillitatis, lower left, and Crisium, the dark circular feature toward the bottom of the mosaic. Also visible in this view are the dark lava plains of the Marginis and Smythii basins, lower right. The Humboldtianum Basin, a 650-kilometer (400-mile) impact structure partly filled with dark volcanic deposits, is visible in the middle of the image. The Moon's north pole is located just inside the shadow zone about a third of the way from the top left of the lighted region. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory. ##### |
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GLL/EM17
This false-color mosaic was
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12/22/92
| Date |
12/22/92 |
| Description |
This false-color mosaic was constructed from a series of 53 images taken through three spectral filters by Galileo's imaging system as the spacecraft flew over the northern regions of the Moon on December 7, 1992. The part of the Moon vlsible from Earth is on the left side in this view. The color mosaic shows compositional variations in parts of the Moon's northern hemisphere. Bright pinkish areas are highlands materials, such as those surrounding the oval lava-filled Crisium impact basin toward the bottom of the picture. B1ue to orange shades indicate volcanic lava flows. To the left of Crisium, the dark blue Mare Tranquillitatis is richer in titanium than the green and orange maria above it. Thin mineral-rich soils associated with relatively recent impacts are represented by light blue colors, the youngest craters have prominent blue rays extending from them. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory. ##### |
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GALILEO
This image is the most detai
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6/22/94
| Date |
6/22/94 |
| Description |
This image is the most detailed picture of the recently discovered natural satellite of asteroid 243 Ida taken by the Galileo Solid-State Imaging camera during its encounter with the asteroid on August 28, 1993. Shuttered through the camera's broadband clear filter as part of a 30-frame mosaic designed to image the asteroid itself, this frame fortuitously captured the previously unknown moon at a range of about 3,900 kilometers (2,400 miles), just over 4 minutes before the spacecraft's closest approach to Ida. Each picture element spans about 39 meters (125 feet) on the surface of the moon. More than a dozen craters larger than 80 meters (250 feet) in diameter are clearly evident, indicating that the moon has suffered numerous collisions from smaller Solar System debris during its history. The larger crater on the terminator is about 300 meters (1,000 feet) across. The satellite is approximately egg-shaped, measuring about 1.2 x 1.4 x 1.6 kilometers (0.75 x 0.87 x 1 mile). At the time this image was shuttered, Ida was about 90 kilometers (56 miles) away from the moon, outside this frame to the left and slightly below center. This image was relayed to Earth from Galileo on June 8, 1994. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory. ##### |
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Jupiter Night-Side Auroras,
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Oval-shaped auroras glow in
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2/5/01
| Date |
2/5/01 |
| Description |
Oval-shaped auroras glow in night-side areas near Jupiter's north and south poles in these images taken by NASA's Cassini spacecraft on Jan. 13, 2001. The lower frame is the first to capture the southern aurora on the planet's night side. Blue lines of longitude and latitude have been added in each frame to indicate position of the glows. Jupiter's auroral ovals are similar to Earth's auroras, often called the northern lights or southern lights, although fluctuations in solar activity play a more important role in the auroras at Earth than at Jupiter. Energetic particles are constantly streaming towards Jupiter on magnetic field lines that intersect the planet's atmosphere on a ring around the magnetic pole. Where the energetic particles hit the upper atmosphere, they cause emission of light, similar to the glow in a fluorescent bulb. In the north (upper image), the magnetic pole is offset from the rotational pole, which is where the blue longitude lines converge, just to the left of the imaged area. The auroral oval appears like a draped necklace that is carried around by the rotation of the planet. In the south (lower image), the magnetic and rotational poles are nearly coincident, so no significant offset is visible. Cassini had passed its closest to Jupiter about two weeks before taking these pictures, so it was in position to see the night side of the planet. It was about 16.5 million kilometers (10.3 million miles) from the planet and about 2.5 degrees below the plane of Jupiter's equator. The smallest features visible are about 100 kilometers (about 60 miles) across. The images were taken by Cassini's narrow-band camera through a filter centered on a light-wave frequency at which hydrogen emits light when it is excited. They have been processed to remove scattered light from the overexposed sunlit crescent of the planet. Hydrogen is a major ingredient of Jupiter's atmosphere. It is not understood why the auroral oval rings are so thin. Cassini images will help scientists figure out what brings about the narrow nature and other features of the auroras, such as the break in the northern oval visible in the upper image. 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/University of Arizona # # # # # |
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Mini Solar System in the Mak
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| Title |
Mini Solar System in the Making |
| Description |
This artist's concept shows a brown dwarf surrounded by a swirling disk of planet-building dust. NASA's Spitzer Space Telescope spotted such a disk around a surprisingly low-mass brown dwarf, or "failed star."Ê The brown dwarf, called OTS 44, is only 15 times the size of Jupiter, making it the smallest brown dwarf known to host a planet-forming, or protoplanetary disk. Astronomers believe that this unusual system will eventually spawn planets. If so, they speculate that OTS 44's disk has enough mass to make one small gas giant and a few Earth-sized rocky planets. OTS 44 is about 2 million years old. At this relatively young age, brown dwarfs are warm and appear reddish in color. With age, they grow cooler and darker. |
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Riding a Trail of Debris
| Title |
Riding a Trail of Debris |
| Description |
This image taken by NASA's Spitzer Space Telescope shows the comet Encke riding along its pebbly trail of debris (long diagonal line) between the orbits of Mars and Jupiter. This material actually encircles the solar system, following the path of Encke's orbit. Twin jets of material can also be seen shooting away from the comet in the short, fan-shaped emission, spreading horizontally from the comet. Encke, which orbits the Sun every 3.3 years, is well traveled. Having exhausted its supply of fine particles, it now leaves a long trail of larger more gravel-like debris, about one millimeter in size or greater. Every October, Earth passes through Encke's wake, resulting in the well-known Taurid meteor shower. This image was captured by Spitzer's multiband imaging photometer when Encke was 2.6 times farther away than Earth is from the Sun. It is the best yet mid-infrared view of the comet at this great distance. The data are helping astronomers understand how rotating comets eject particles as they circle the Sun. |
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'Mini-Me' Solar System
| Title |
'Mini-Me' Solar System |
| Description |
This artist's conception shows the relative size of a hypothetical brown dwarf-planetary system (below) compared to our own solar system. A brown dwarf is a cool or "failed" star, which lacks the mass to ignite and shine like our Sun. NASA's Spitzer Space Telescope set its infrared eyes on an extraordinarily low-mass brown dwarf called OTS 44 and found a swirling disk of planet-building dust. At only 15 times the mass of Jupiter, OTS 44 is the smallest known brown dwarf to host a planet-forming, or protoplanetary, disk. Astronomers believe that this unusual system will eventually spawn planets. If so, they speculate that OTS 44's disk has enough mass to make one small gas giant and a few Earth-sized rocky planets. Examples of these possible planets are depicted at the bottom of this picture, circling a low-mass brown dwarf. Above, the bodies of our own solar system have been drawn to the same scale. In each system, the terrestrial planets have been enlarged and the distances between the planets and their parent bodies have been scaled down for easier viewing. |
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Jupiter-Family Comets
| Title |
Jupiter-Family Comets |
| Description |
These images of the Jupiter-family comets Johnson (top) and Shoemaker-Levy 3 (bottom) were both taken with Spitzer's multiband imaging photometer (MIPS) at a wavelength of 24 microns. The fan-shaped region that stretches upward from Johnson's nucleus (yellow ball in the middle) represents the dust "tail" of the comet. Dust tails are created when small particles from a comet are swept backward by the Sun's radiation pressure. The image of Shoemaker-Levy 3 (bottom) does not show a dust tail. In both images the long thin trail of emission that precisely follows the orbit of the comet is believed to be a debris trail of solid material, ranging from millimeters to centimeters in size. Such particles, called meteoroids, are the same size as those that appear in meteor showers when they enter the Earth's atmosphere. Because any trace of water would evaporate in the Sun's heat, astronomers do not believe that debris trails contain ice. These meteoroids have evaded detection in previous comet images because they are relatively faint in visible light. At mid-infrared wavelengths, meteoroids give off infrared radiation. Any object with an internal temperature higher than absolute zero (-273.5 degrees Celsius or zero Kelvin) produces thermal radiation, objects in the inner solar system give off radiation at mid-infrared wavelengths. Consequently, MIPS allows astronomers to study the production of meteoroids by comets whose orbits do not cross the Earth's path. Spitzer images have also shown that there is more mass in the debris trails of comets than in their dust tails and gases. The results of Spitzer's observations are consistent with those obtained by space probes that encountered comet Halley in 1986. In Halley's case, large particles produced by the comet were not only detected, but caused significant damage to the probes. |
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Birth of an Unusual Planetar
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| Title |
Birth of an Unusual Planetary System |
| Description |
This artist's animation shows a brown dwarf surrounded by a swirling disk of planet-building dust. NASA's Spitzer Space Telescope spotted such a disc around a surprisingly low-mass brown dwarf, or "failed star." The brown dwarf, called OTS 44, is only 15 times the size of Jupiter, making it the smallest brown dwarf known to host a planet-forming, or protoplanetary disk. Astronomers believe that this unusual system will eventually spawn planets. If so, they speculate that OTS 44's disk has enough mass to make one small gas giant and a few Earth-sized rocky planets. OTS 44 is about 2 million years old. At this relatively young age, brown dwarfs are warm and appear reddish in color. With age, they grow cooler and darker. |
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Belt of Dust
| Title |
Belt of Dust |
| Description |
This artist's concept depicts a distant hypothetical solar system, similar to the one recently discovered with the Spitzer Space Telescope [ http://www.spitzer.caltech.edu/Media/happenings/20051214/index.shtml ]. In this artist's rendering, a narrow asteroid belt filled with rocks and dusty debris, orbits a star similar to our own Sun when it was approximately 30 million years old (about the time Earth formed). Within the belt a hypothetical planet also circles the star. Using the Spitzer's heat-seeking infrared eyes, astronomers have recently discovered a similar debris belt surrounding a distant star. While no planets were detected directly by Spitzer, the narrow size of the newly discovered belt hints at the possibility of a planetary system. Just as small moons shepherd ice grains orbiting Saturn into discrete rings, and just as Jupiter tends the outer edge of our solar system's asteroid belt, astronomers suspect one or more planets may be confining the debris within this narrow ring around the star. |
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Comet 'Bites the Dust' Aroun
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| Title |
Comet 'Bites the Dust' Around Dead Star |
| Description |
This artist's concept illustrates a comet being torn to shreds around a dead star, or white dwarf, called G29-38. NASA's Spitzer Space Telescope observed a cloud of dust around this white dwarf that may have been generated from this type of comet disruption. The findings suggest that a host of other comet survivors may still orbit in this long-dead solar system. The white dwarf G29-38 began life as a star that was about three times as massive as our sun. Its death involved the same steps that the sun will ultimately undergo billions of years from now. According to theory, the G29-38 star became brighter and brighter as it aged, until it bloated up into a dying star called a red giant. This red giant was large enough to engulf and evaporate any terrestrial planets like Earth that happened to be in its way. Later, the red giant shed its outer atmosphere, leaving behind a shrunken skeleton of star, called a white dwarf. If the star did host a planetary system, outer planets akin to Jupiter and Neptune and a remote ring of icy comets would remain. The Spitzer observations provide observational evidence for this orbiting outpost of comet survivors. Astronomers speculate that one such comet was knocked into the inner regions of G29-38, possibly by an outer planet. As the comet approached very close to the white dwarf, it may have been torn apart by the star's tidal forces. Eventually, all that would be left of the comet is a disk of dust. This illustration shows a comet in the process of being pulverized: part of it still exists as a chain of small clumps, while the rest has already spread out into a dusty disk. Comet Shoemaker-Levy 9 broke apart in a similar fashion when it plunged into Jupiter in 1994. |
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Itsy Bitsy Solar System
| Title |
Itsy Bitsy Solar System |
| Description |
This artist's conception compares a hypothetical solar system centered around a tiny "sun" (top) to a known solar system centered around a star, called 55 Cancri, which is about the same size as our sun. NASA's Spitzer Space Telescope, in combination with other ground-based and orbiting telescopes, discovered the beginnings of such a miniature solar system 500 light-years away in the Chamaeleon constellation. The tiny system consists of an unusually small "failed" star, or brown dwarf, called Cha 110913-773444, and a surrounding disk of gas and dust that might one day form planets. At a mass of only eight times that of Jupiter, the brown dwarf is actually smaller than several known extrasolar planets. The largest planet in the 55 Cancri system is about four Jupiter masses. Astronomers speculate that the disk around Cha 110913-773444 might have enough mass to make a small gas giant and a few Earth-sized rocky planets, as depicted here around the little brown dwarf. |
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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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Comet Schwassmann-Wachmann 1
| Title |
Comet Schwassmann-Wachmann 1 |
| Description |
NASA's new Spitzer Space Telescope has captured an image of an unusual comet that experiences frequent outbursts, which produce abrupt changes in brightness. Periodic comet Schwassmann-Wachmann I (P/SW-1) has a nearly circular orbit just outside that of Jupiter, with an orbital period of 14.9 years. It is thought that the outbursts arise from the build-up of internal gas pressure as the heat of the Sun slowly evaporates frozen carbon dioxide and carbon monoxide beneath the blackened crust of the comet nucleus. When the internal pressure exceeds the strength of the overlying crust, a rupture occurs, and a burst of gas and dust fragments is ejected into space at speeds of 450 miles per hour (200 meters per second). This 24-micron image of P/SW-1 was obtained with Spitzer's multiband imaging photometer. The image shows thermal infrared emission from the dusty coma and tail of the comet. The nucleus of the comet is about 18 miles (30 kilometers) in diameter and is too small to be resolved by Spitzer. The micron-sized dust grains in the coma and tail stream out away from the Sun. The dust and gas comprising the comet's nucleus is part of the same primordial materials from which the Sun and planets were formed billions of years ago. The complex carbon-rich molecules they contain may have provided some of the raw materials from which life originated on Earth. Schwassmann-Wachmann 1 is thought to be a member of a relatively new class of objects called "Centaurs," of which 45 objects are known. These are small icy bodies with orbits between those of Jupiter and Neptune. Astronomers believe that Centaurs are recent escapees from the Kuiper Belt, a zone of small bodies orbiting in a cloud at the distant reaches of the solar system. Two asteroids, 1996 GM36 (left) and 5238 Naozane (right) were serendipitously captured in the comet image. Because they are closer to us than the comet and have faster orbital velocities, they appear to move relative to the comet and background stars, thereby producing a slight elongated appearance. The Spitzer data have allowed astronomers to use thermal measurements, which reduce the uncertainties of visible-light albedo (reflectivity) measurements, to determine their size. With radii of 1.4 and 3.0 kilometers, these are the smallest main-belt asteroids yet measured by infrared means. |
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Comet Schwassmann-Wachmann 1
| Title |
Comet Schwassmann-Wachmann 1 |
| Description |
NASA's new Spitzer Space Telescope has captured an image of an unusual comet that experiences frequent outbursts, which produce abrupt changes in brightness. Periodic comet Schwassmann-Wachmann I (P/SW-1) has a nearly circular orbit just outside that of Jupiter, with an orbital period of 14.9 years. It is thought that the outbursts arise from the build-up of internal gas pressure as the heat of the Sun slowly evaporates frozen carbon dioxide and carbon monoxide beneath the blackened crust of the comet nucleus. When the internal pressure exceeds the strength of the overlying crust, a rupture occurs, and a burst of gas and dust fragments is ejected into space at speeds of 450 miles per hour (200 meters per second). This 24-micron image of P/SW-1 was obtained with Spitzer's multiband imaging photometer. The image shows thermal infrared emission from the dusty coma and tail of the comet. The nucleus of the comet is about 18 miles (30 kilometers) in diameter and is too small to be resolved by Spitzer. The micron-sized dust grains in the coma and tail stream out away from the Sun. The dust and gas comprising the comet's nucleus is part of the same primordial materials from which the Sun and planets were formed billions of years ago. The complex carbon-rich molecules they contain may have provided some of the raw materials from which life originated on Earth. Schwassmann-Wachmann 1 is thought to be a member of a relatively new class of objects called "Centaurs," of which 45 objects are known. These are small icy bodies with orbits between those of Jupiter and Neptune. Astronomers believe that Centaurs are recent escapees from the Kuiper Belt, a zone of small bodies orbiting in a cloud at the distant reaches of the solar system. Two asteroids, 1996 GM36 (left) and 5238 Naozane (right) were serendipitously captured in the comet image. Because they are closer to us than the comet and have faster orbital velocities, they appear to move relative to the comet and background stars, thereby producing a slight elongated appearance. The Spitzer data have allowed astronomers to use thermal measurements, which reduce the uncertainties of visible-light albedo (reflectivity) measurements, to determine their size. With radii of 1.4 and 3.0 kilometers, these are the smallest main-belt asteroids yet measured by infrared means. |
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Gas Giants Form Quickly
| Title |
Gas Giants Form Quickly |
| Description |
This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas. Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years. The scientists came to this conclusion after searching for traces of gas around 15 different sun-like stars, most with ages ranging from 3 million to 30 million years. With the help of Spitzer's Infrared Spectrometer instrument, they were able to search for relatively warm gas in the inner regions of these star systems, an area comparable to the zone between Earth and Jupiter in our own solar system. They also used ground-based radio telescopes to search for cooler gas in the outer regions of these systems, an area comparable to the zone around Saturn and beyond. |
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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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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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Where Planets Take Up Reside
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| Title |
Where Planets Take Up Residence |
| Description |
This diagram illustrates that mature planetary systems like our own might be more common around twin, or binary, stars that are either really close together, or really far apart. NASA's Spitzer Space Telescope observed that debris disks, which are signposts of mature planetary systems, are more abundant around the tightest and widest of binary stars it studied. Specifically, the infrared telescope found significantly more debris disks around binary stars that are 0 to 3 astronomical units apart (top panel) and 50 to 500 astronomical units apart (bottom panel) than binary stars that are 3 to 50 astronomical units apart (middle panel). An astronomical unit is the distance between Earth and the sun. In other words, if two stars are as far apart from each other as the sun is from Jupiter (5 astronomical units) or Pluto (40 astronomical units), they would be unlikely to host a family of planetary bodies. The Spitzer data also revealed that debris disks circle all the way around both members of a close-knit binary (top panel), but only a single member of a wide duo (bottom panel). This could explain why the intermediately spaced binary systems (middle panel) can be inhospitable to planetary disks: they are too far apart to support one big disk around both stars, and they are too close together to have enough room for a disk around just one star. |
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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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Saturn's Magnetosphere
| Description |
Saturn's Magnetosphere |
| Full Description |
The magnetosphere is an area of space, around a planet, that is controlled by that planet's magnetic field. Saturn is surrounded by a giant magnetic field, lined up with the rotation axis of the planet. This cannot be explained by current theories. Cassini may explain how the puzzling magnetic field of Saturn is generated. This magnetic field may also cause strange features in the rings called 'spokes'. These markings fall across the rings like spokes in a wheel and may be caused by electrically charged particles caught up in the magnetic field, but there are as yet no detailed theories about them. The brief reconnaissance encounters of the Pioneer 11 and the two Voyager spacecraft have provided most of our current information about the structure and dynamics of Saturn's magnetosphere. Here are some things that we do know: * Saturn's 'bow shock', the region point where the solar wind and the planet's magnetic field meet, much like the bow wave of a ship, is between 20 and 35 times Saturn's radius out into space. * The thickness of the bow shock is about 2000 kilometres. * Saturn's internal magnetic field is closely aligned with the planet's axis of rotation (within 1 degree). Saturn's magnetosphere appears to be intermediate in nature to those of Earth and Jupiter. As with Jupiter's magnetosphere, the dayside inner magnetosphere is mostly driven by the fast planetary rotation. However at night, it is expected that the nightside and outer magnetosphere is primarily driven by the solar wind, as is the case on Earth. * There is an electrical current (the 'equatorial ring current') flowing with about 10 000 000 Amps around 600 000 kilometres above Saturn. * Saturn Kilometric Radiation (SKR) is the principal radio emission from Saturn. SKR is believed to be linked to the way electrons in the solar wind interact with the magnetic field at Saturn's poles. Click here for a high resolution version. *Credit:* ESA |
| Date |
June 2, 2004 |
|
Saturn's Magnetosphere
| Description |
Saturn's Magnetosphere |
| Full Description |
The magnetosphere is an area of space, around a planet, that is controlled by that planet's magnetic field. Saturn is surrounded by a giant magnetic field, lined up with the rotation axis of the planet. This cannot be explained by current theories. Cassini may explain how the puzzling magnetic field of Saturn is generated. This magnetic field may also cause strange features in the rings called 'spokes'. These markings fall across the rings like spokes in a wheel and may be caused by electrically charged particles caught up in the magnetic field, but there are as yet no detailed theories about them. The brief reconnaissance encounters of the Pioneer 11 and the two Voyager spacecraft have provided most of our current information about the structure and dynamics of Saturn's magnetosphere. Here are some things that we do know: * Saturn's 'bow shock', the region point where the solar wind and the planet's magnetic field meet, much like the bow wave of a ship, is between 20 and 35 times Saturn's radius out into space. * The thickness of the bow shock is about 2000 kilometres. * Saturn's internal magnetic field is closely aligned with the planet's axis of rotation (within 1 degree). Saturn's magnetosphere appears to be intermediate in nature to those of Earth and Jupiter. As with Jupiter's magnetosphere, the dayside inner magnetosphere is mostly driven by the fast planetary rotation. However at night, it is expected that the nightside and outer magnetosphere is primarily driven by the solar wind, as is the case on Earth. * There is an electrical current (the 'equatorial ring current') flowing with about 10 000 000 Amps around 600 000 kilometres above Saturn. * Saturn Kilometric Radiation (SKR) is the principal radio emission from Saturn. SKR is believed to be linked to the way electrons in the solar wind interact with the magnetic field at Saturn's poles. Click here for a high resolution version. *Credit:* ESA |
| Date |
June 2, 2004 |
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Dwarfed by Storms
| Description |
Dwarfed by Storms |
| Full Description |
Tiny Mimas is dwarfed by a huge white storm and dark waves on the edge of a cloud band in Saturn's atmosphere. Although the east-west winds on Saturn are stronger than on Earth or even Jupiter, the contrast in appearance between these zones is more muted, and the departures of the wind speeds from east to west are lower. The image was taken with the Cassini spacecraft narrow angle camera on Sept. 25, 2004, at a distance of 7.8 million kilometers (4.8 million miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 727 nanometers. The image scale is 46 kilometers (29 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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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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Huygens Landing Site Revisit
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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 |
January 13, 2006 This is an animated artist interpretation of the area surrounding the Huygens landing site, based on images and data returned Jan. 14, 2005. On January 14, 2005, the European Space Agency's (ESA) Huygens probe reached the upper layer of Titan's atmosphere and landed on the surface after a parachute descent 2 hours and 28 minutes later. As part of the joint NASA/ESA/ASI mission to Saturn and its moons, the Huygens probe was sent from the Cassini spacecraft to explore Titan, Saturn's largest moon. Titan's organic chemistry may be like that of the primitive Earth around 4000 million years ago, and it may hold clues about how life began on our planet. + Read the Feature |
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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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Lightning Sounds from Saturn
| 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 |
This audio clip was created from radio signals received by the radio and plasma wave science instrument on the Cassini spacecraft. The bursty radio emissions were generated by lightning flashes on Saturn and are similar to the crackles and pops one hears on an AM radio during a thunderstorm on Earth. This storm on Saturn occurred on January 23 and 24, 2006. The clip compresses two hours of observations into about 28 seconds. Therefore, every second of the audio clip corresponds to about 4 minutes, 18 seconds. 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 radio and plasma wave science team is based at the University of Iowa, Iowa City. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the instrument team's home page, http://www-pw.physics.uiowa.edu/cassini/ . Credit: NASA/JPL/University of Iowa |
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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 |
Cassini's high-gain antenna is able to operate at S, X, Ka, and Ku-band frequencies. In addition to communications (X-band between Earth and orbiter, and S-band from probe to orbiter), radio science measurements are also possible for probing Saturn and satellite gravity fields, rings, atmospheres and surfaces. This artist's conception illustrates the capacity of the Cassini radar to map the haze-enshrouded surface of Titan using the Ku-band frequency. Radar images of the surface are taken at a typical resolution of about 500 meters. Altimetry and passive radiometry measurements are also made. Approximately 1% of Titan's surface can be mapped by the high-resolution Cassini radar during a Titan flyby. Full mapping coverage of Titan will be accomplished by combining the high-resolution radar mapping with lower-resolution passive radiometry. (P-46225AC) |
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Titan Flyby Animation
| Description |
Titan Flyby Animation |
| Full Description |
This computer animation shows the planned observations by Cassini spanning roughly a two-day period surrounding its first very close approach to Titan on Tuesday, Oct. 26, at 8:30 a.m. Pacific Daylight Time, at Saturn, or 9:50 PDT, Earth-received time. The animation extends from Oct. 25, 10:20 a.m. PDT, to Oct. 26, 7:20 p.m. PDT. Red indicates observations to be taken in infrared, white in visible light, and purple in utlraviolet. Green indicates radar observations. The name of the instrument team that has designed the observation - imaging science subsystem, visual and infrared spectrometer, composite infrared spectrometer, ultraviolet imaging spectrograph, radar -- is shown. The globe of Titan is covered with the map of imaging data shown in PIA 06116. 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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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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T-17 Flyby -- Raw Image N000
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| Description |
T-17 Flyby -- Raw Image N00065334 |
| Full Description |
+ See T-17 Flyby Page N00065334.jpg was taken Sept. 8, 2006 and received on Earth Sept. 8, 2006. The camera was pointing toward TITAN at approximately 137,854 kilometers away, and the image was taken using the CL1 and CB3 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2007. For more information on raw images check out our frequently asked questions section. *Image Credit:* NASA/JPL |
| Date |
September 11, 2006 |
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Revealing Titan's Surface
| 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 |
These three pictures were created from a sequence of images acquired by Cassini's imaging science subsystem on Oct. 25, 2004, 38 hours before its closest approach to Titan. They illustrate how the details of Titan's surface can be revealed through image processing techniques. The picture on the left is a single image that has undergone only basic cleaning of corrupted pixels and imperfections in the camera's charge coupled device, a light-sensitive detector similar to those found in digital cameras. In the middle frame, multiple images were used to enhance the contrast detected from Titan's surface and to reduce the blurring effect of atmospheric haze. The picture on the right has been further processed to sharpen the edges of features. The processed images reveal sharp boundaries between dark and light regions on the surface, there are no shadows produced by topography in these images. The bright area on the center right is Xanadu, a region that has been observed previously from Earth and by Cassini. To the west of Xanadu lies an area of dark material that completely surrounds brighter features in some places. Narrow linear features, both dark and bright, can also be seen. It is not clear what geologic processes created these features, although it seems clear that the surface is being shaped by more than impact craters alone. The very bright features near Titan's south pole are clouds similar to those observed during the distant Cassini flyby on July 2, 2004. The region on the left side of these images will be targeted by higher-resolution observations as Cassini passes close to Titan on Oct. 26, 2004. All of these images were acquired by Cassini on Oct. 25, 2004, at an altitude of 702,000 kilometers (436,000 miles) and a pixel scale of 4.2 kilometers (2.6 miles). The Sun was illuminating Titan from nearly behind the spacecraft. 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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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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Shorefront Property, Anyone?
| Description |
Shorefront Property, Anyone? |
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This lake is part of a larger image taken by the Cassini radar instrument during a flyby of Saturn's moon Titan on Sept. 23, 2006. It shows clear shorelines that are reminiscent of terrestrial lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water. Centered near 74 degrees north, 65 degrees west longitude, this lake is roughly 20 kilometers by 25 kilometers (12 to 16 miles) across. It features several narrow or angular bays, including a broad peninsula that on Earth would be evidence that the surrounding terrain is higher and confines the liquid. Broader bays, such as the one seen at right, might result when the terrain is gentler, as for example on a beach. 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 . Credit: NASA/JPL |
| Date |
September 26, 2006 |
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In Saturn's Shadow (Color-ex
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In Saturn's Shadow (Color-exagerated view) |
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+ 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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Long-lived Vortices
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Long-lived Vortices |
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With no solid land to obstruct their progress, dark vortices often roll through Saturn's atmosphere for months or years, before merging with other vortices. On Earth, the continents usually halt the progress of large storms, like hurricanes. Vortices like these are part of the general circulation pattern of east-west flowing cloud bands, called jets, on Saturn. The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 939 nanometers. The image was obtained with the Cassini spacecraft wide-angle camera on Aug. 16, 2006 at a distance of approximately 259,000 kilometers (161,000 miles) from Saturn. Image scale is 12 kilometers (7 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 |
September 26, 2006 |
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Topography on Titan
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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 graph, produced using preliminary altimetry data from Cassini's radar instrument, shows relative surface heights on Titan. The data were acquired on Oct. 26, 2004, during Cassini's first close encounter with Titan, at distances ranging from 5,000 to 10,000 kilometers (3,100 to 6,200 miles). The location observed is near latitude 25 degrees north, longitude 5 degrees west. The data show a variation in height of only about 150 meters (490 feet) over the 400-kilometer-long (250-mile-long) track, indicating that in this region Titan is remarkably flat. Fine details in the data are likely to be noise, and not surface features. The area marked "downlink data dropout" was lost during transmission from the spacecraft to Earth but will be recovered by a later data replay. 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 instrument team is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. For the latest news about the Cassini-Huygens mission visit http://www.nasa.gov/cassini . For more information about the mission visit http://saturn.jpl.nasa.gov . Image Credit: NASA/JPL |
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Titan's |
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This Cassini radar image shows two lakes "kissing" each other on the surface of Saturn's moon Titan. The image from a flyby on Sept. 23, 2006, covers an area about 60 kilometers (37 miles) wide by 40 kilometers (25 miles) high. This pass was primarily dedicated to the ion and neutral mass spectrometer instrument, so although, the volume of radar data was small, scientists were amazed to see Earth-like lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lakes likely contain a combination of methane and ethane, not water. In this image, near 73 degrees north latitude, 46 degrees west longitude, two lakes are seen, each 20 to 25 kilometers (12 to 16 miles) across. They are joined by a relatively narrow channel. The lake on the right has lighter patches within it, indicating that it may be slowly drying out as the northern summer approaches. 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 . Credit: NASA/JPL |
| Date |
September 26, 2006 |
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Titan Flyby -- Oct. 9, 2006
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Titan Flyby -- Oct. 9, 2006 -- (Raw Image) |
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N00067472.jpg was taken on Oct. 10, 2006 and received on Earth Oct. 10, 2006. The camera was pointing toward TITAN at approximately 189,368 kilometers away, and the image was taken using the CL1 and CB3 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2007. For more information on raw images check out our frequently asked questions section. *Image Credit:* NASA/JPL/Space Science Institute |
| Date |
October 10, 2006 |
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Nope, Not Jupiter!
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Nope, Not Jupiter! |
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Saturn, more bland in appearance than Jupiter to the naked eye, puts on a dramatic display in this contrast-enhanced image taken with the Cassini spacecraft. This view shows a giant oval in the ringed planet's southern hemisphere that is somewhat smaller than, but resembles in appearance, Jupiter's long-lived Great Red Spot. On Jupiter such southern-hemisphere features usually exhibit counterclockwise - or anti-cyclonic - rotation, like high pressure systems on Earth. Imaging scientists will be interested to watch the evolution of this and similar storms, to see if it is longer-lived than is typical for Saturnian storms. Also seen in the image at higher southern latitudes are the common dark belts and bright zones, usually associated with alternating eastward and westward jets. These jets often produce boundary turbulence (like that seen toward the bottom right) due to wind shear and density differences between adjacent bands. The image was taken with the Cassini spacecraft narrow angle camera on Dec. 6, 2004, at a distance of approximately 3.3 million kilometers (2.1 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 58 degrees. The filter used is centered at 727 nanometers - an area of the electromagnetic spectrum where methane gas is strongly absorbing. The image scale is 38 kilometers (24 miles) per pixel. This image has been slightly contrast-enhanced to aid visibility. 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 and the Cassini imaging team home page, http://ciclops.org. *Credit*: NASA/JPL/Space Science Institute |
| Date |
December 24, 2004 |
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Titan Flyby - Oct. 25, 2006
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Titan Flyby - Oct. 25, 2006 |
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*Cassini to Find Out What Titan's Dunes Are Made Of * During a flyby of Saturn's moon Titan on Wed., Oct. 25, the Cassini spacecraft will obtain the first detailed maps of the composition of this moon's Earth-like features, including dunes, rocky plains, steep highlands and possible volcanoes and lakes. + View Flyby Page |
| Date |
October 23, 2006 |
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Saturn's Surprisingly Stormy
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Saturn's Surprisingly Stormy South |
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These images of Saturn's south pole, taken by two different instruments on Cassini, show the hurricane-like storm swirling there and features in the clouds at various depths surrounding the pole. Different wavelengths reveal the height of the clouds, which span tens of kilometers in altitude. The four monochrome images displayed here were acquired by the imaging science subsystem, the blue and red images in the bottom row were taken by the visual and infrared mapping spectrometer. The images are arranged in order of increasing wavelength in nanometers as follows: (top row) 460 nm, 752 nm, 728 nm, (bottom row) 890 nm, 2,800 nm, 5,000 nm. At the center of the cauldron of storms spinning around the south pole is the south pole itself, which literally appears to be the eye of this vast polar storm system. As in a hurricane on Earth, the south polar "eye" is relatively clear of clouds and is surrounded by a wall of towering clouds that cast shadows into the center. However, while morphologically similar, it is not clear if this vortex operates in the same fashion as a terrestrial hurricane. In most of the images, the center of the polar storm is quite dark, indicating an unusually cloud-free atmosphere in the upper skies, which are otherwise typically inhabited by bright ammonia clouds. This polar hole in the ammonia cloud layer represents the eye of the hurricane-like storm. Unusually dark clouds likely exist at the bottom of this deep hole, enhancing the murkiness there. The first image in this montage (at upper left) shows a muted eye, due to the enhanced scattering of light from the atmosphere itself at this blue wavelength (460 nanometers), just as in the blue skies of Earth. In the last image at bottom right, the eye appears relatively bright. This image is taken at a wavelength of 5,000 nanometers, where the dominant source of light is the thermal glow of the planet itself. The bright thermal glow seen in this polar hole again shows that the eye is relatively cloud-free to unusual depths. In the imaging science subsystem images, the eye looks dark at wavelengths where methane gas absorbs the light (728 nanometers and 890 nanometers, at upper right and lower left) and only the highest clouds are visible, confirming that the clouds within the eye are deeper than their surroundings. This effect is also seen in visual and infrared mapping spectrometer images that show gas absorption. In the visual and infrared mapping spectrometer image taken at 2,800 nanometers, four times the wavelength of light visible to the human eye, this cloud clearing appears dark, which is consistent with the idea that the atmosphere above any distinct clouds is unusually deep there. The eye is some 1,500 kilometers (930 miles) across, and is surrounded by a distinct ring of clouds some 300 kilometers (185 miles) across. The images also indicate the prevalence of smaller but vertically well-developed storms across the entire south polar region, indicating the, extent to which convection characterizes the area. Literally hundreds of storm clouds encircle the pole, appearing as dark spots in the infrared spectrometer thermal image (red image) and as both bright and dark spots in images taken in sunlight (blue image). Each of these spots represents a storm. These pictures reveal that Saturn's south pole is a cauldron of storm activity, unlike anything ever seen on any planet. The individual storms surrounding the pole are seen as dark "leopard spots" in the thermal image (red) taken at a wavelength of 5,000 nanometers, some seven times the wavelength of light visible to the human eye. Here, these spots are blocking the thermal light, or heat, from the interior of Saturn. The storm clouds are thus seen in silhouette against Saturn's thermal glow. The effectiveness of these clouds in blocking Saturn's interior thermal glow indicates that the storm clouds are unusually thick, extending deep down into Saturn's atmosphere, and are comprised of relatively large cloud particles, likely condensates formed in upwelling air currents. The large number of dark, circular leopard spots at the south pole seen at 5,000 nanometer wavelength, and their correlation with the features seen in sunlight at 2,800 nanometer wavelength, indicates that convective activity extending over dozens of kilometers in altitude is surprisingly rampant in the south polar region. Why such unusual dynamics exist there is perhaps linked to Saturn's southern summer, which is the season Saturn is in now. Observations taken over the next few years, as the south pole season changes from summer to fall, will help scientists understand the role seasons play in driving the dramatic meteorology at the south pole of Saturn. The images in this montage were acquired on Oct. 11, 2006, when Cassini was approximately 340,000 kilometers (210,000 miles) from Saturn. The original imaging science subsystem images have a scale of about 17 kilometers (11 miles) per pixel. The visual and infrared spectrometer images have a scale of about 174 kilometers (108 miles) per pixel. The images have been resized to approximately the same scale for presentation here. 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. 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. The Cassini imaging team homepage is at http://ciclops.org. The visual and infrared mapping spectrometer team homepage is at, http://wwwvims.lpl.arizona.edu. *Credit:* NASA/JPL/Space Science Institute/University of Arizona |
| Date |
November 9, 2006 |
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Looking Saturn in the Eye
| Description |
Looking Saturn in the Eye |
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+ View Movie Cassini stares deep into the swirling hurricane-like vortex at Saturn's south pole, where the vertical structure of the clouds is highlighted by shadows. Such a storm, with a well-developed eye ringed by towering clouds, is a phenomenon never before seen on another planet. This 14-frame movie shows a swirling cloud mass centered on the south pole, around which winds blow at 550 kilometers (350 miles) per hour. The frames have been aligned to make the planet appear stationary, while the sun appears to revolve about the pole in a counterclockwise direction. The clouds inside the dark, inner circle are lower than the surrounding clouds, which cast a shadow that follows the sun. At the beginning of the movie, the sun illuminates directly from the top, and by the end it illuminates from the left. The width of the shadow and the height of the sun above the local horizon yield a crude estimate of the height of the surrounding clouds relative to the clouds in the center. The shadow-casting clouds tower 30 to 75 kilometers (20 to 45 miles) above those in the center. This is two to five times greater than the tallest terrestrial thunderstorms and two to five times the height of clouds surrounding the eye of a terrestrial hurricane. Such a height difference arises because Saturn's hydrogen-helium atmosphere is less dense at comparable pressures than Earth's atmosphere, and is therefore more distended in the vertical dimension. The south polar storm, which displays two spiral arms of clouds extending from the central ring and spans the dark area inside a thick, brighter ring of clouds, is approximately 8,000 kilometers (5,000 miles) across, which is considerably larger than a terrestrial hurricane. Eye-wall clouds are a distinguishing feature of hurricanes on Earth. They form where moist air flows inward across the ocean's surface, rising vertically and releasing a load of precipitation around an interior circular region of descending air, which is the eye itself. Though it is uncertain whether moist convection is driving this storm, as is the case with Earthly hurricanes, the dark 'eye' at the pole, the eye-wall clouds and the spiral arms together indicate a hurricane-like system. The distinctive eye-wall clouds especially have not been seen on any planet beyond Earth. Even Jupiter's Great Red Spot, much larger than Saturn's polar storm, has no eye, no eye-wall, and is relatively calm at the center. This giant Saturnian storm is apparently different from hurricanes on Earth because it is locked to the pole, does not drift around like terrestrial hurricanes and because it does not form over liquid water oceans. The images were acquired over a period of three hours on Oct. 11, 2006, when Cassini was approximately 340,000 kilometers (210,000 miles) from Saturn. Image scale is about 17 kilometers (11 miles) per pixel. The images were taken with the wide-angle camera using a spectral filter sensitive to wavelengths of infrared light, centered at 752 nanometers. All frames have been contrast enhanced using digital image processing techniques. The unprocessed images show an oblique view toward the pole, and have been reprojected to show the planet from a perspective directly over the south pole. 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 |
November 9, 2006 |
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