|
|
Saturn's Blue Cranium
| Description |
Saturn's Blue Cranium |
| Full Description |
Saturn's northern hemisphere is presently a serene blue, more befitting of Uranus or Neptune, as seen in this natural color image from Cassini. Light rays here travel a much longer path through the relatively cloud-free upper atmosphere. Along this path, shorter wavelength blue light rays are scattered effectively by gases in the atmosphere, and it is this scattered light that gives the region its blue appearance. Why the upper atmosphere in the northern hemisphere is so cloud-free is not known, but may be related to colder temperatures brought on by the ring shadows cast there. Shadows cast by the rings surround the pole, looking almost like dark atmospheric bands. The ring shadows at higher latitudes correspond to locations on the ringplane that are farther from the planet -- in other words, the northernmost ring shadow in this view is made by the outer edge of the A ring. Spots of bright clouds also are visible throughout the region. This view is similar to an infrared image obtained by Cassini at nearly the same time (see http://photojournal.jpl.nasa.gov/catalog/PIA06567). The infrared view shows a great deal more detail in the planet's atmosphere, however. Images obtained using red, green and blue spectral filters were combined to create this color view. The images were taken with the Cassini spacecraft wide angle camera on Dec. 14, 2004, at a distance of 719,200 kilometers (446,900 miles) from Saturn. The image scale is about 39 kilometers (24 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . For images visit the Cassini imaging team home page http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
February 8, 2005 |
|
Old and New Again
| Description |
Old and New Again |
| Full Description |
Miranda, an icy moon of Uranus (see PIA 00141). Miranda is 470-kilometers-wide (290 miles), nearly as large as Enceladus (504 kilometers, or 313 miles wide). The similarities in size and tectonic history on these objects may suggest that remarkably similar physical processes have controlled the separate geological evolutions of these bodies. The images that comprise this mosaic were obtained during Cassini's closest approach to Enceladus on March 9, 2005. The images was taken in visible green light with the Cassini spacecraft narrow-angle camera at a distance of approximately 29,000 kilometers (18,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 46 degrees. Resolution in the original images is about 170 meters (560 feet) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . For additional images visit the Cassini imaging team homepage http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute, This false-color Cassini mosaic of Saturn's moon Enceladus captures in a single view, much of the frigid moon's diverse geology. Cratered terrain dominates most of the scene. The relatively dense accumulation of impact craters implies that this terrain is among the oldest on the moon's surface. Near the bottom of the picture is a crater 20 kilometers wide (12-mile) with a prominent dome-shaped structure in its center. The entire area is transected by a complex web of fractures and faults, some are as narrow as a few hundred meters, others as wide as 5 kilometers (3 miles). The rims and interiors of many craters seem to be sliced by a pervasive system of narrow, parallel grooves into slabs or lanes that typically are a kilometer (about a half-mile) in width. The widely varied appearances of fractures in this region attest to the fact that the surface of Enceladus has been shaped by a long history of intense tectonic activity. The oldest fractures are characterized by a soft, muted appearance and are overprinted by numerous, superimposed impact craters. More recent fractures exhibit topographic relief that is relatively "crisp" in appearance, and they appear to slice through pre-existing impact craters and older fractures. On the right side of the image is a conspicuous and twisted network of ridges and troughs forming a distinct tectonic region on Enceladus. The paucity of craters and the sharp appearance of the topography in this area indicate that this is a relatively young terrain on Enceladus. This view is a composite of images taken using filters sensitive to ultraviolet (centered at 338 nanometers), green (centered at 568 nanometers), and near-infrared (centered at 930 nanometers) light, and has been processed to accentuate subtle color differences. The uppermost surface of these terrains has a relatively uniform grayish color in this picture, suggesting that it is covered with materials of homogeneous composition and grain size. However, many of the fractures reveal a distinctly different color (represented by pale-bluish tones in this false-color image) than the typical surface materials. These "colored" fractures seem to penetrate down to a material that is texturally or compositionally different than most of the material at the surface. One possibility is that the walls of the fractures expose outcrops of solid ice, or ice with different grain-sizes compared to powdery surface materials that blanket flat-lying surfaces. It is also possible that the color identifies some compositional difference between buried ice and ice at the surface. The distinct coloration of "youthful" fracture walls are nearly absent in the oldest fractures. This is consistent with the possibility that the older fractures are covered with a drape of particulate material which mantles nearly all the oldest features on the satellite. In the early 1980's, NASA's Voyager mission to the outer planets revealed a strikingly similar arrangement of terrains on |
| Date |
March 16, 2005 |
|
Find the Moon
| title |
Find the Moon |
| date |
10.01.2003 |
| description |
New Satellites of Uranus Discovered in 2003 Discovery images of one of the newly found Uranus satellites S/2003 U3 showing its motion relative to background stars and galaxies. Scott S. Sheppard and David Jewitt at the University of Hawaii have discovered 2 new outer satellites of Uranus designated S/2001 U2 and S/2003 U3. The discovery images were obtained from the Subaru 8.3m telescope atop Mauna Kea in Hawaii on August 29, 2003. Further observations by the Hawaii team using the Gemini 8.2m telescope allowed Brian Marsden at the Minor Planet Center to link the satellites to independent discovery observations obtained in 2001 by a group lead by Matt Holman and JJ Kavelaars. The 2001 observations were not enough to determine if the objects were satellites of Uranus and no reliable orbits were found. They were than lost until discovery in 2003 by the Hawaii team. The new Uranus satellite S/2001 U2 was announced by the International Astronomical Union on October 1 ( IAU Circular 8213 ) and S/2003 U3 on October 9 ( IAU Circular 8217 ). The new satellites are about 12 and 11 kilometers in diameter respectively. S/2001 U2 has an orbital period of about 8 years and is in a retrograde orbit. S/2003 U3 has an orbital period of just over 4 years and is the first prograde irregular satellite discovered around Uranus. All the giant planets now have known prograde and retrograde irregular satellites. Uranus now has 27 known satellites of which 9 have irregular orbits. See http://www.ifa.hawaii.edu/~sheppard/satellites/uranus2003.html for more information. |
|
A New Look at Uranus
| title |
A New Look at Uranus |
| description |
Japan's Subaru Telescope captured this near-infrared image of Uranus and moons Miranda (top center) and Ariel (bottom left). The image, created with three different filters, shows methane, the dominant component of Uranus's atmosphere, as blue. *Image Credit/Copyright*: National Astronomical Observatory of Japan |
|
Gas Giant Interiors
| title |
Gas Giant Interiors |
| description |
*Jupiter* Jupiter's composition is mainly hydrogen and helium. In contrast to planetary bodies covered with a hard surface crust (the Earth, for example), the jovian surface is gaseous-liquid, rendering the boundary between the atmosphere and the planet itself almost indistinguishable. Below the roughly 1000-kilometer-thick atmosphere, a layer of liquid hydrogen extends to a depth of 20,000 kilometers. Even deeper, it is believed that there is a layer of liquid metallic hydrogen at a pressure of 3 million bars. The planet core is believed to comprise iron-nickel alloy, rock, etc., at a temperature estimated to exceed 20,000C. *Saturn* As with Jupiter, Saturn is mainly composed of hydrogen and helium and is observed to be of extremely low density. In fact, Saturn's mean density is only about two-thirds that of water. The Saturn atmosphere comprises, in descending order of altitude, a layer of ammonia, a layer of ammonium hydrogen sulfide, and a layer of ice. Below this, the saturnian surface is a stratum of liquid hydrogen (as in the case of Jupiter) underlain with a layer of liquid metallic hydrogen. It is believed that the liquid hydrogen layer of Saturn is thicker than that of Jupiter, while the liquid metallic hydrogen layer may be thinner. The planet's core is estimated to be composed of rock and ice. *Uranus* Uranus is gaseous in composition, mainly comprising hydrogen and helium as in the case of Jupiter and Saturn. The planet atmosphere is mostly hydrogen but also includes helium and methane. The planet core is estimated to be rock and ice encompassed by an outer layer of ice comprised of water, ammonium, and methane. *Neptune * The atmosphere of Neptune consists of mainly hydrogen, methane and helium, similar to Uranus. Below it is a liquid hydrogen layer including helium and methane. The lower layer is made up of the liquid hydrogen compounds oxygen and nitrogen. It is believed that the planet core comprises rock and ice. Neptune's average density, as well as the greatest proportion of core per planet size, is the greatest among all the gaseous planets. *Image Credit:* Lunar and Planetary Institute |
|
Planet Temperatures
| title |
Planet Temperatures |
| description |
In general, the surface temperature of the planets decreases with increasing distance from the Sun. Venus is an exception because its dense atmosphere acts as a greenhouse and heats the surface to above the melting point of lead (3280C). Mercury rotates slowly and has a thin atmosphere, and consequently, the nightside temperature can be more than 5000C lower than the dayside temperature shown on the diagram. Temperatures for the gas giants (Jupiter, Saturn, Uranus, and Neptune) are shown at a level in the atmosphere equal in pressure to sea level on Earth. Temperatures are in both Fahrenheit and Celsius, and the planets are not shown to scale. *Image Credit*: Lunar and Planetary Institute |
|
Gas Planet Sizes
| title |
Gas Planet Sizes |
| description |
Jupiter, Saturn, Uranus, and Neptune are known as the jovian (Jupiter-like) planets because they are all gigantic compared with Earth, and they have a gaseous nature like Jupiter's. The jovian planets are also referred to as the gas giants, although some or all of them might have small solid cores. This diagram shows the approximate relative sizes of the jovian planets. *Image Credit*: Lunar and Planetary Institute |
|
Voyager 2 Launch
| title |
Voyager 2 Launch |
| date |
08.20.1977 |
| description |
Voyager 2 was launched August 20, 1977, sixteen days before Voyager 1 aboard a Titan-Centaur rocket. Their different flight trajectories caused Voyager 2 to arrive at Jupiter four months later than Voyager 1, thus explaining their numbering. The initial mission plan for Voyager 2 specified visits only to Jupiter and Saturn. The plan was augmented in 1981 to include a visit to Uranus, and again in 1985 to include a flyby of Neptune. After completing the tour of the outer planets in 1989, the Voyager spacecraft began exploring interstellar space. The Voyager mission has been managed by NASA's Office of Space Science and the Jet Propulsion Laboratory. *Image Credit*: NASA |
|
Solar System Family Portrait
| title |
Solar System Family Portrait |
| description |
These six narrow-angle color images were made from the first ever 'portrait' of the solar system taken by Voyager 1, which was more than 4 billion miles from Earth and about 32 degrees above the ecliptic. The spacecraft acquired a total of 60 frames for a mosaic of the solar system which shows six of the planets. Mercury is too close to the sun to be seen. Mars was not detectable by the Voyager cameras due to scattered sunlight in the optics, and Pluto was not included in the mosaic because of its small size and distance from the sun. These blown-up images, left to right and top to bottom are Venus, Earth, Jupiter, and Saturn, Uranus, Neptune. The background features in the images are artifacts resulting from the magnification. The images were taken through three color filters -- violet, blue and green -- and recombined to produce the color images. Jupiter and Saturn were resolved by the camera but Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposure times. Earth appears to be in a band of light because it coincidentally lies right in the center of the scattered light rays resulting from taking the image so close to the sun. Earth was a crescent only 0.12 pixels in size. Venus was 0.11 pixel in diameter. The planetary images were taken with the narrow-angle camera (1500 mm focal length). *Image Note*: This 'Portrait' contains 18 frames taken through the Narrow Angle camera using the Violet, Blue, and Green Filters. The label information describes only 3 of these frames. *Image Credit*: NASA |
|
Hubble Captures Full View of
…
| title |
Hubble Captures Full View of Uranus's Rings on Edge |
| date |
08.14.2007 |
| description |
NASA's Hubble Space Telescope captures a rare view of the entire ring system of the planet Uranus, tilted edge-on to Earth. The rings were photographed with Hubble's Wide Field Planetary Camera 2 on August 14, 2007. The edge-on rings appear as spikes above and below the planet. The rings cannot be seen running fully across the face of the planet because the bright glare of the planet has been blocked out in the HST photo (a small amount of residual glare appears as a fan-shaped image artifact, along with an edge between the exposure for the inner and outer rings). A much shorter color exposure of the planet has been photo-composited to show its size and position relative to the ring plane. Earthbound astronomers only see the rings' edge every 42 years as the planet follows a leisurely 84-year orbit about the Sun. However, the last time the rings were tilted edge-on to Earth astronomers didn't even know they existed. The fainter outer rings appear in the 2003 Hubble Space Telescope images, but were not noticed there until they were seen in the 2005 images and the previous ones were analyzed more carefully. Uranus has a total of 13 dusty rings. Credit: NASA [ http://www.nasa.gov/ ], ESA [ http://www.spacetelescope.org/ ], and M. Showalter (SETI Institute) |
|
Charon Discovery Image
| title |
Charon Discovery Image |
| date |
06.22.1978 |
| description |
On 22 June 1978, an astronomer at the U.S. Naval Observatory in Washington, D.C. was making routine measurements of photographic plates taken with the 1.55-meter (61-inch) Kaj Strand Astrometric Reflector at the USNO Flagstaff Station in Arizona. The purpose of these images was to refine the orbit of the far-flung planet Pluto to help compute a better ephemeris for this distant object. Astronomer James W. Christy had noticed that a number of the images of Pluto appeared elongated, but images of background stars on the same plate did not. Other plates showed the planet as a tiny, round dot. Christy examined a number of Pluto images from the USNO archives, and he noticed the elongations again. Furthermore, the elongations appeared to change position with respect to the stars over time. After eliminating the possibility that the elongations were produced by plate defects and background stars, the only plausible explanation was that they were caused by a previously unknown moon orbiting Pluto at a distance of about 19,600 kilometers (12,100 miles) with a period of just over six days. On 7 July 1978, the discovery was formally announced to the astronomical community and the world by the IAU Central Bureau for Astronomical Telegrams via IAU Circular 3241. The discovery received the provisional designation "1978 P 1", Christy proposed the name "Charon", after the mythological ferryman who carried souls across the river Acheron, one of the five mythical rivers that surrounded Pluto's underworld. Over the course of the next several years, another USNO astronomer, the late Robert S. Harrington, calculated that Pluto and its newly-found moon would undergo a series of mutual eclipses and occultations, beginning in early 1985. On 17 February 1985 the first successful observation of one of these transits was made at with the 0.9-meter (36-inch) reflector at the University of Texas McDonald Observatory, within 40 minutes of Harrington's predicted time. The IAU Circular announcing these confirming observations was issued on 22 February 1985. With this confirmation, the new moon was officially named Charon. Pluto was discovered at Lowell Observatory in 1930 by the late Clyde W. Tombaugh, an amateur astronomer from Kansas who was hired by the Observatory specifically to photograph the sky with a special camera and search for the planet predicted by the Observatory's founder, Percival Lowell. Lowell had deduced the existence of a "Planet X" by studying small anomalies in the orbits of Uranus and Neptune. As it turned out, Pluto's discovery was almost entirely serendipitous, Pluto's tiny mass was far too small to account for the anomalies, which were resolved when Voyager 2 determined more precise masses for Uranus and Neptune. The discovery of Charon has led to a much better understanding of just how tiny Pluto is. Its diameter is about 2274 km (1413 miles), and its mass is 0.25% of the mass of the Earth. Charon has a diameter of about 1172 kilometers (728, miles) and a mass of about 22% that of Pluto. The two worlds circle their common center of mass with a period of 6.387 days and are locked in a "super-synchronous" rotation: observers on Pluto's surface would always see Charon in the same part of the sky relative to their local horizon. Normally Pluto is considered the most distant world in the solar system, but during the period from January 1979 until February 1999 it was actually closer to the Sun than Neptune. It has the most eccentric and inclinced orbit of any of the major planets. This orbit won't bring Pluto back to its discovery position until the year 2178! *Image Credit*: U.S. Naval Observatory |
|
Uranus' innermost satellite
…
| title |
Uranus' innermost satellite Miranda |
| date |
01.24.1986 |
| description |
Miranda, innermost of Uranus' large satellites, is seen at close range in this Voyager 2 image, taken Jan. 24, 1986, as part of a high-resolution mosaicing sequence. Voyager was some 36,000 kilometers (22,000 miles) away from Miranda. This clear-filter, narrow-angle image shows an area about 250 km (150 mi) across, at a resolution of about 800 meters (2,600 feet). Two distinct terrain types are visible: a rugged, higher-elevation terrain (right) and a lower, striated terrain. Numerous craters on the rugged, higher terrain indicate that it is older than the lower terrain. Several scarps, probably faults, cut the different terrains. The impact crater in the lower part of this image is about 25 km (15 mi) across. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. *Image Credit*: NASA |
|
Uranus
| title |
Uranus |
| description |
This is a view of Uranus taken by Voyager 2. This image was taken through three color filters and recombined to produce the color image. JPL manages and controls the Voyager project for NASA's Office of Space Science. *Image Credit*: NASA |
|
Uranus Ring System
| title |
Uranus Ring System |
| description |
This dramatic Voyager 2 picture reveals a continuous distribution of small particles throughout the Uranus ring system. Voyager took this image while in the shadow of Uranus, at a distance of 236,000 kilometers (142,000 miles and a resolution of about 33 km (20 ml). This unique geometry -- the highest phase angle at which Voyager imaged the rings -- allows us to see lanes of fine dust particles not visible from other viewing angles. All the previously known rings are visible here, however, some of the brightest features in the image are bright dust lanes not previously seen. The combination of this unique geometry and a long, 96 second exposure allowed this spectacular observation, acquired through the clear filter of Voyager's wide-angle camera. The long exposure produced a noticeable, non-uniform smear as well as streaks due to trailed stars. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. *Image Credit*: JPL |
|
Hubble Captures Detailed Ima
…
| title |
Hubble Captures Detailed Image of Uranus' Atmosphere |
| date |
07.03.1995 |
| description |
Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere. Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail. The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere. Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal. This false color picture was assembled from several exposures taken July 3, 1995 by the Wide Field Planetary Camera-2. The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science. This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu *Image Credit*: Erich Karkoschka (University of Arizona Lunar & Planetary Lab) and NASA |
|
Hubble Spots Northern Hemisp
…
| title |
Hubble Spots Northern Hemispheric Clouds on Uranus |
| date |
07.31.1997 |
| description |
Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time. Uranus is sometimes called the "sideways" planet, because its rotation axis tipped more than 90 degrees from the planet's orbit around the Sun. The "year" on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness). Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds. Two images are shown here. The "aqua" image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb (rightmost edge). The "red" image (on the right) is taken at 6,190 Angstroms, and is sensitive to absorption by methane molecules in the planet's atmosphere. The banded structure of Uranus is evident, and the small cloud near the northern limb is now visible. Scientists are expecting that the discrete clouds and banded structure may become even more pronounced as Uranus continues in its slow pace around the Sun. "Some parts of Uranus haven't seen the Sun in decades," says Dr. Hammel, "and historical records suggest that we may see the development of more banded structure and patchy clouds as the planet's year progresses." Some scientists have speculated that the winds of Uranus are not symmetric around the planet's equator, but no clouds were visible to test those theories. The new data will provide the opportunity to measure the northern winds. Hammel and colleagues expect to have results soon. The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by, the Goddard Spaced Flight Center for NASA's Office of Space Science. This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu *Image Credit*: Heidi Hammel (Massachusetts Institute of Technology), NASA |
|
Uranian Moons
| title |
Uranian Moons |
| date |
01.26.1986 |
| description |
This "family portrait" of Uranus' five largest moons was compiled from images sent back Jan. 20, 1986, by the Voyager 2 spacecraft. The pictures were taken through a clear filter from distances of 5.0 million to 6.1 million kilometers (3.1 million to 3.8 million miles). In this comparison, we see the relative sizes and relativities of the satellites. From left, in order of increasing distance from the planet, they are Miranda, Ariel, Umbriel, Titania and Oberon. The two largest, Oberon and Titania, are about half the size of Earth's Moon, or roughly, 1,600 kilometers (1,000 miles) in diameter. Miranda, smallest of the five, has about one-quarter to one-third the diameter. Even in these distant views, the satellites exhibit distinct differences in appearance. On average, Oberon and Titania reflect about 20 percent of the sunlight, Umbriel about 12 percent, Ariel and Miranda about 30 percent. Ariel shows the largest contrast on its surface, with the brightest areas about 25 percent. All five satellites show only slight color variations on their surfaces, with their average color being very nearly gray. The best views of the satellites will be obtained Jan. 24, the day of closest approach. *Image Credit*: NASA |
|
All Planet Sizes
| title |
All Planet Sizes |
| description |
This illustration shows the approximate sizes of the planets relative to each other. Outward from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Jupiter's diameter is about 11 times that of the Earth's and the Sun's diameter is about 10 times Jupiter's. Pluto's diameter is slightly less than one-fifth of Earth's. The planets are not shown at the appropriate distance from the Sun. *Image Credit*: Lunar and Planetary Laboratory |
|
Anniversary Rings
| title |
Anniversary Rings |
| description |
Until the discovery of Uranus' rings 25 years ago, astronomers believed Saturn was the only ringed planet. It is now known that all four of our Solar System's gas giants have rings. |
|
Near-Infrared Uranus and Moo
…
| title |
Near-Infrared Uranus and Moons (Unlabeled) |
| date |
11.19.2002 |
| description |
This photo shows a near-infrared view of the giant planet Uranus with rings and some of its moons, obtained on November 19, 2002, with the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile). From top to bottom, the moons are Titania, Umbriel, Portia, Miranda, Puck and Ariel. The unidentified, round object to the left is a background star. *Image Credit*: ESO |
|
Hubble Tracks Clouds on Uran
…
| title |
Hubble Tracks Clouds on Uranus |
| date |
07.28.1997 |
| description |
Taking its first peek at Uranus, NASA Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) has detected six distinct clouds in images taken July 28,1997. The image on the right, taken 90 minutes after the left-hand image, shows the planet's rotation. Each image is a composite of three near-infrared images. They are called false-color images because the human eye cannot detect infrared light. Therefore, colors corresponding to visible light were assigned to the images. (The wavelengths for the "blue,""green," and "red" exposures are 1.1, 1.6, and 1.9 micrometers, respectively.) At visible and near-infrared light, sunlight is reflected from hazes and clouds in the atmosphere of Uranus. However, at near-infrared light, absorption by gases in the Uranian atmosphere limits the view to different altitudes, causing intense contrasts and colors. In these images, the blue exposure probes the deepest atmospheric levels. A blue color indicates clear atmospheric conditions, prevalent at mid-latitudes near the center of the disk. The green exposure is sensitive to absorption by methane gas, indicating a clear atmosphere, but in hazy atmospheric regions, the green color is seen because sunlight is reflected back before it is absorbed. The green color around the south pole (marked by "+") shows a strong local haze. The red exposure reveals absorption by hydrogen, the most abundant gas in the atmosphere of Uranus. Most sunlight shows patches of haze high in the atmosphere. A red color near the limb (edge) of the disk indicates the presence of a high-altitude haze. The purple color to the right of the equator also suggests haze high in the atmosphere with a clear atmosphere below. The five clouds visible near the right limb rotated counterclockwise during the time between both images. They reach high into the atmosphere, as indicated by their red color. Features of such high contrast have never been seen before on Uranus. The clouds are almost as large as continents on Earth, such as Europe. Another cloud (which barely can be seen) rotated along the path shown by the black arrow. It is located at lower altitudes, as indicated by its green color. The rings of Uranus are extremely faint in visible light but quite prominent in the near infrared. The brightest ring, the epsilon ring, has a variable width around its circumference. Its widest and thus brightest part is at the top in this image. Two fainter, inner rings are visible next to the epsilon ring. Eight of the 10 small Uranian satellites, discovered by Voyager 2, can be seen in both images. Their sizes range from about 25 miles (40 kilometers) for Bianca to 100 miles (150 kilometers) for Puck. The smallest of these satellites have not been detected since the departure of Voyager 2 from Uranus in 1986. These eight satellites revolve around Uranus in less than a day. The inner ones are faster than the outer ones. Their motion in the 90 minutes between both images is, marked in the right panel. The area outside the rings was slightly enhanced in brightness to improve the visibility of these faint satellites. The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science. This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/ *Image Credit*: NASA |
|
Uranus and Moons (Labeled)
| title |
Uranus and Moons (Labeled) |
| date |
11.19.2002 |
| description |
This European Southern Observatoryimage show Uranus and several of its moons in near-infrared. From top to bottom, the moons are Titania, Umbriel, Portia, Miranda, Puck and Ariel. The unidentified, round object to the left is a background star. The image scale in indicated by the bar. *Image Credit*: European Southern Observatory |
|
Neptune's Interior
| title |
Neptune's Interior |
| description |
The atmosphere of Neptune, similar to Uranus, consists of mainly hydrogen, methane, and helium. Below it is a liquid hydrogen layer including helium and methane. The lower layer is liquid hydrogen compounds, oxygen, and nitrogen. It is believed that the planet core comprises rock and ice. Average density, as well as the greatest proportion of core per planet size, is the greatest among the gaseous planets. *Image Credit*: Lunar and Planetary Institute |
|
Sharper Vision
| title |
Sharper Vision |
| date |
07.09.2004 |
| description |
The power of the Keck telescope's adaptive optics system is clear in this image of Uranus, its rings and the moon Miranda. The two sets of exposures compare Keck AO system off (left) to Keck AO system on (right). Upper: Uranus, its rings and moon Miranda at near infrared wavelengths of 2.2 microns. Lower: Uranus and its atmospheric details as seen in near infrared wavelengths of 1.6 microns. The image has been doubled in size. Date is Universal Time. *Image Credit*:Heidi Hammel, Space Science Institute, Boulder, CO/Imke de Pater, University of California, Berkeley/ W. M. Keck Observatory |
|
Uranus from Earth
| title |
Uranus from Earth |
| date |
07.11.2004 |
| description |
An infrared composite image of the two hemispheres of Uranus obtained with Keck adaptive optics. The component colors of blue, green, and red were obtained from images made at near infrared wavelengths of 1.26, 1.62, and 2.1 microns respectively. The images were obtained on July 11 and 12, 2004. The representative balance of these infrared images which were selected to display the vertical structure of atmospheric features gives a reddish tint to the rings, an artifact of the process. The North pole is at 4 o'clock. *Image Credit*: Lawrence Sromovsky, University of Wisconsin-Madison/ W. M. Keck Observatory |
|
Miranda as seen by Voyager 2
| Title |
Miranda as seen by Voyager 2 |
| Full Description |
Flying by in early 1986, Voyager 2 captured this picture of Miranda, which enabled scientists to study this moon of Uranus in much greater detail than ever before. Discovered in 1948 by Gerard Peter Kuiper, Miranda is named for the daughter of the wily Prospero in Shakespeare's "The Tempest." It is the eleventh known satellite of Uranus and the innermost large moon of Uranus It was necessary that Voyager 2 passed by Miranda, not for scientific reasons, but simply for the gravity assist it needed to go on to Neptune. Due to the position of the entire Solar System, Miranda provided the energy to throw Voyager 2 to Neptune. Before Voyager, Miranda was largely ignored as it is not the largest moon and did not seem to have any other outstanding qualities. Fortunately, however, Voyager passed close enough to Miranda to provide scientists with fascinating photographs that captivated astronomers. About half ice and half rock, Miranda's surface has terraced layers that indicate both older and new surfaces coexisting. Since the mixing of ancient and recent surfaces is rare in planetary geology, scientists have postulated two explanations for the different ages of the numerous valleys and cliffs on Miranda. One theory is that Miranda could have shattered as many as five times and was then reassembled. Another hypothesis is that partly melted ice upwells forced new surfaces to emerge. |
| Date |
01/25/1986 |
| NASA Center |
Jet Propulsion Laboratory |
|
Pioneer 10 Trajectory
| Title |
Pioneer 10 Trajectory |
| Full Description |
This image, drawn in 1970, is an artist's rendering of the Pioneer 10 spacecraft trajectory, with the planets labeled and a list of the instruments that were intended to be flown. Before the use of computer animation, artists were hired by JPL and NASA to depict a spacecraft in flight, for use as a visual aid to promote the project during development. Pioneer 10 was managed by NASA Ames Research Center in Moffett Field, California. The Pioneer F spacecraft, as it was known before launch, was designed and built by TRW Systems Group, Inc. JPL developed three instruments that flew on the spacecraft: Magnetic Fields, S-Band Occultation, and Celestial Mechanics, as well as running the Deep Space Network which provided tracking and data system support. Caltech was responsible for the Jovian Infrared Thermal Structure experiment. Pioneer was very successful, crossing the orbit of Mars and the asteroid belt beyond it, encountering, studying, and photographing Jupiter, then crossing the orbits of Saturn, Uranus, and Neptune. It left the solar system in 1983 and has been contacted several times in the past few years. As of July 2001, the spacecraft was still able to send a return signal to Earth. At Jupiter, the experiments of Pioneer were used to examine the environmental and atmospheric characteristics of the giant planet. Pioneer was also the vital precursor to all future flights to the outer solar system. It determined that a spacecraft could safely fly through the asteroid belt. It also measured the intensity of Jupiter's radiation belt so that NASA could design future Jupiter (and other outer planets) orbiters. |
| Date |
03/07/1972 |
| NASA Center |
Jet Propulsion Laboratory |
|
Solar System Montage
| Title |
Solar System Montage |
| Full Description |
This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus and Neptune. The spacecraft responsible for these images are as follows: the Mercury image was taken by Mariner 10, the Venus image by Magellan, the Earth image by Galileo, the Mars image by Viking, and the Jupiter, Saturn, Uranus and Neptune images by Voyager. Pluto is not shown as no spacecraft has yet visited it. The inner planets (Mercury, Venus, Earth, Moon, and Mars) are roughly to scale to each other, the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other. Actual diameters are given below: Sun 1,390,000 km Mercury 4,879 km Venus 12,104 km Earth 12,756 km Moon 3,475 km Mars 6,794 km Jupiter 142.984 km Saturn 120,536 km Uranus 51,118 km Neptune 49,528 km Pluto 2,390 km |
| Date |
04/09/1999 |
| NASA Center |
Jet Propulsion Laboratory |
|
Solar System Montage of Voya
…
| Title |
Solar System Montage of Voyager Images |
| Full Description |
This montage of images taken by the Voyager spacecraft of the planets and four of Jupiter's moons is set against a false-color Rosette Nebula with Earth's moon in the foreground. Studying and mapping Jupiter, Saturn, Uranus, Neptune, and many of their moons, Voyager provided scientists with better images and data than they had ever had before or expected from the program. Although launched sixteen days after Voyager 2, Voyager 1's trajectory was a faster path, arriving at Jupiter in March 1979. Voyager 2 arrived about four months later in July 1979. Both spacecraft were then directed to Saturn with Voyager 1 arriving in November 1980 and Voyager 2 in August 1981. Voyager 2 was then diverted to the remaining gas giants, Uranus in January 1986 and Neptune in August 1989. Data collection continues by both Voyager 1 and 2 as the renamed Voyager Interstellar Mission searches for the edge of the solar wind influence (the heliopause) and exits the Solar System. A shortened list of the discoveries of Voyager 1 and 2 include:the discovery of the Uranian and Neptunian magnetospheres (magnetic environments caused by various types of planet cores), the discovery of twenty-two new satellites including three at Jupiter, three at Saturn, ten at Uranus, and six at Neptune, Io was found to have active volcanism (the only other Solar System body than Earth to be confirmed), Triton was found to have active geyser-like structures and an atmosphere, Auroral Zones (where gases become excited after being hit by solar particles) were discovered at Jupiter, Saturn, and Neptune, Jupiter was found to have rings, Neptune, originally thought to be too cold to support such atmospheric disturbances, had large-scale storms. |
| Date |
UNKNOWN |
| NASA Center |
Jet Propulsion Laboratory |
|
Uranus
| Title |
Uranus |
| Full Description |
This computer enhancement of a Voyager 2 image, emphasizes the high-level haze in Uranus' upper atmosphere. Clouds are obscured by the overlying atmosphere. JPL manages and controls the Voyager project for NASA's Office of Space Science, Washington, DC. |
| Date |
01/01/1986 |
| NASA Center |
Jet Propulsion Laboratory |
|
Voyager 2 Launch
| Title |
Voyager 2 Launch |
| Full Description |
Voyager 2 was launched August 20, 1977, sixteen days before Voyager 1 aboard a Titan-Centaur rocket. Their different flight trajectories caused Voyager 2 to arrive at Jupiter four months later than Voyager 1, thus explaining their numbering. The initial mission plan for Voyager 2 specified visits only to Jupiter and Saturn. The plan was augmented in 1981 to include a visit to Uranus, and again in 1985 to include a flyby of Neptune. After completing the tour of the outer planets in 1989, the Voyager spacecraft began exploring interstellar space. The Voyager mission has been managed by NASA's Office of Space Science and the Jet Propulsion Laboratory. |
| Date |
08/20/1977 |
| NASA Center |
Kennedy Space Center |
|
Voyager Spacecraft During Vi
…
| Title |
Voyager Spacecraft During Vibration Testing |
| Full Description |
Two Voyager spacecraft were launched in 1977 to explore the outer planets and some of their satellites. A prototype Voyager spacecraft is shown at NASA's Jet Propulsion Laboratory in Pasadena, California, as it successfully passed vibration tests which simulated the expected launch environment. The large parabolic antenna at the top is 3.7 meters in diameter and was used at both S-band and X-band radio frequencies for communicating with Earth over the great distances from the outer planets. The spacecraft received electrical power from three nuclear power sources (lower left). The shiny cylinder on the left side under the antenna contained a folded boom, which extended after launch to hold a magnetometer instrument thirteen meters away from the body of the spacecraft. The truss-like structure on the right side is the stowed instrument boom which supported three science instruments and a scan platform. The scan platform allowed the accurate pointing of two cameras and three other science instruments at Jupiter, Saturn, the rings of Saturn, Jupiter's moons, Saturn's moons, Uranus, moons of Uranus, and Neptune. |
| Date |
03/25/1977 |
| NASA Center |
Jet Propulsion Laboratory |
|
Voyager Tour Montage
| Title |
Voyager Tour Montage |
| Full Description |
This montage of images of the planets visited by Voyager 2 was prepared from an assemblage of images taken by the Voyager 2 spacecraft. The Voyager Project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, California. |
| Date |
08/01/1989 |
| NASA Center |
Jet Propulsion Laboratory |
|
Ariel at Voyager Closest App
…
| Title |
Ariel at Voyager Closest Approach |
| Description |
This picture is part of the highest-resolution Voyager 2 imaging sequence of Ariel, a moon of Uranus about 1,300 kilometers (800 miles) in diameter. The clear-filter, narrow-angle image was taken Jan. 24, 1986, from a distance of 130,000 km (80,000 mi). The complexity of Ariel's surface indicates that a variety of geologic processes have occurred. The numerous craters, for example, are indications of an old surface bombarded by meteoroids over a long period. Also conspicuous at this resolution, about 2.4 km (1.5 mi), are linear grooves (evidence of tectonic activity that has broken up the surface) and smooth patches (indicative of deposition of material). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.26.1986 |
|
Ariel's Densely Pitted Surfa
…
| Title |
Ariel's Densely Pitted Surface |
| Description |
This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on Jan. 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 km (750 mi) in diameter, the resolution here is 2.4 km (1.5 mi). Much of Ariel's surface is densely pitted with craters 5 to 10 km (3 to 6 mi) across. These craters are close to the threshold of detection in this picture. Numerous valleys and fault scarps crisscross the highly pitted terrain. Voyager scientists believe the valleys have formed over down-dropped fault blocks (graben), apparently, extensive faulting has occurred as a result of expansion and stretching of Ariel's crust. The largest fault valleys, near the terminator at right, as well as a smooth region near the center of this image, have been partly filled with deposits that are younger and less heavily cratered than the pitted terrain. Narrow, somewhat sinuous scarps and valleys have been formed, in turn, in these young deposits. It is not yet clear whether these sinuous features have been formed by faulting or by the flow of fluids. JPL manages the Voyager project for NASA's Office of Space Science. |
| Date |
01.27.1986 |
|
Neptune's rings
| Title |
Neptune's rings |
| Description |
This wide-angle Voyager 2 image, taken through the camera's clear filter, is the first to show Neptune's rings in detail. The two main rings, about 53,000 km (33,000 miles) and 63,000 km (39,000 miles) from Neptune, are 5 to 10 times brighter than in earlier images. The difference is due to lighting and viewing geometry. In approach images, the rings were seen in light scattered backward toward the spacecraft at a 15-degree phase angle. However, this image was taken at a 135-degree phase angle as Voyager left the planet. That geometry is ideal for detecting microscopic particles that forward-scatter light preferentially. The fact that Neptune's rings are so much brighter at that angle means the particle-size distribution is quite different from most of Uranus' and Saturn's rings, which contain fewer dust-size grains. However, a few components of the Saturnian and Uranian ring systems exhibit forward-scattering behavior: The F ring and the Encke Gap ringlet at Saturn, and 1986U1R at Uranus. They are also narrow, clumpy ringlets with kinks, and are associated with nearby moonlets too small to detect directly. In this image, the main clumpy arc, composed of three features each about 6 to 8 degrees long, is clearly seen. This image was obtained when Voyager was 1.1 million km (683,000 miles) from Neptune. Exposure time was 111seconds. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. |
| Date |
08.26.1989 |
|
Oberon at Voyager Closest Ap
…
| Title |
Oberon at Voyager Closest Approach |
| Description |
This Voyager 2 picture of Oberon is the best the spacecraft acquired of Uranus' outermost moon. The picture was taken shortly after 3:30 a.m. PST on Jan. 24, 1986, from a distance of 660,000 kilometers (410,000 miles). The color was reconstructed from images taken through the narrow-angle camera's violet, clear and green filters. The picture shows features as small as 12 km (7 mi) on the moon's surface. Clearly visible are several large impact craters in Oberon's icy surface surrounded by bright rays similar to those seen on Jupiter's moon Callisto. Quite prominent near the center of Oberon's disk is a large crater with a bright central peak and a floor partially covered with very dark material. This may be icy, carbon-rich material erupted onto the crater floor sometime after the crater formed. Another striking topographic feature is a large mountain, about 6 km (4 mi) high, peeking out on the lower left limb. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.25.1986 |
|
Bright patches on Ariel
| Title |
Bright patches on Ariel |
| Description |
Distinct bright patches are visible on Ariel, the brightest of Uranus' five largest satellites. Voyager 2 obtained this image Jan. 22, 1986, from a distance of 2.52 million kilometers (1.56 million miles). The clear-filter image, obtained with the narrow-angle camera, shows a resolution of 47 km (29 miles). Ariel is about 1,300 km (800 mi) in diameter. This image shows several distinct bright areas that reflect nearly 45 percent of the incident sunlight, on average, the satellite displays a reflectivity of about 25-30 percent. The bright areas are probably fresh water ice, perhaps excavated by impacts. The south pole of Ariel is slightly off center of the disk in this view. Voyager 2 will obtain its best views of the satellite on Jan. 24, at a closest-approach distance of 127,000 km (79,000 mi). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.23.1986 |
|
Outer part of the Uranian ri
…
| Title |
Outer part of the Uranian ring system |
| Description |
Voyager 2's wide-angle camera captured this view of the outer part of the Uranian ring system the morning of Jan. 24, 1986, just 11 minutes before passing through the ring plane. The spacecraft was 125,000 kilometers (78,000 miles) away when it obtained this clear-filter view, the resolution is slightly better than 9 km (6 mi). The brightest, outermost ring is known as epsilon. Interior to epsilon lie (from top) the newly discovered 1Oth ring of Uranus -- designated 1986UR1 and barely visible here -- and then the delta, gamma and eta rings. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.26.1986 |
|
Color Voyager 2 Image Showin
…
| Title |
Color Voyager 2 Image Showing Crescent Uranus |
| Description |
This image shows a crescent Uranus, a view that Earthlings never witnessed until Voyager 2 flew near and then beyond Uranus on January 24, 1986. This planet's natural blue-green color is due to the absorption of redder wavelengths in the atmosphere by traces of methane gas. Uranus' diameter is 32,500 miles, a little over four times that of Earth. The hazy blue-green atmosphere probably extends to a depth of around 5,400 miles, where it rests above what is believed to be an icy or liquid mixture (an 'ocean') of water, ammonia, methane, and other volatiles, which in turn surrounds a rocky core perhaps a little smaller than Earth. |
| Date |
06.01.1990 |
|
Rings of Uranus
| Title |
Rings of Uranus |
| Description |
This silhouetted image of the rings of Uranus was taken by the Voyager 2 spacecraft on Jan. 24, 1986, just 27 minutes before its closest approach to the planet. A half-second exposure was made with the wide-angle camera at a distance of 63,300 kilometers (39,300 miles). This image shows the nine originally known rings appearing as dark lines against the brighter clouds of the planet. The most prominent ring, called epsilon, appears at the right, barely visible at the left are the three rings known simply as 4, 5 and 6. The Uranian rings are extremely dark. The unique geometry of this view --with the rings against a bright background -- was chosen to ensure that an image could be obtained with a relatively fast exposure. The relative widths and spacing of the rings appear slightly different from other views because of the effects of foreshortening and ring inclinations. The resolution of the image is about 9 km (5 miles). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
02.21.1986 |
|
Rings of Uranus
| Title |
Rings of Uranus |
| Description |
This Voyager 2 image of the Uranian rings delta, gamma, eta, beta and alpha (from top) was taken Jan. 23, 1986. The spacecraft was 1.12 million kilometers (690,000 miles) away when its narrow-angle camera obtained this clear-filter view. This image illustrates the broad outer component and narrow inner component of the eta ring, which orbits Uranus at a radius of some 47,000 km (29,000 mi). The broad component is considerably more transparent than the dense, narrow inner eta component, as well as the other narrow rings shown. Resolution here is about 10 km (6 mi). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.25.1986 |
|
Rings of Uranus at 1.44 kilo
…
| Title |
Rings of Uranus at 1.44 kilometers |
| Description |
The outer rings of Uranus are visible in this Voyager 2 image, obtained Jan. 23, 1986, from a distance of 1.44 million kilometers (890,000 miles). The outermost and brightest ring, called epsilon, is visible along with the fainter and narrower delta and gamma rings (from left). This clear-filter, 15-second exposure was shuttered by Voyager's narrow-angle camera. The resolution of this image is about 15 km (9 mi). The epsilon ring is resolved into two bright components separated by a darker lane of material. Voyager scientists believe this is caused by a thinning of the ring material away from the edges of the ring. This image was part of a sequence of pictures designed to search for moons orbiting within the rings and responsible for their narrow appearance. One of two such "shepherd" moons discovered by Voyager -- found Jan. 20 and designated 1986U7 -- is visible as the elongated bright feature midway between the epsilon and delta rings. The moon appears elongated because its orbital motion smeared its image during the long exposure. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.24.1986 |
|
Solar System Montage
| Title |
Solar System Montage |
| Description |
This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus and Neptune. The spacecraft responsible for these images are as follows: the Mercury image was taken by Mariner 10, the Venus image by Magellan, the Earth image by Galileo, the Mars image by Viking, and the Jupiter, Saturn, Uranus and Neptune images by Voyager. |
| Date |
02.01.1996 |
|
Solar System Portrait - 60 F
…
| Title |
Solar System Portrait - 60 Frame Mosaic |
| Description |
The cameras of Voyager 1 on Feb. 14, 1990, pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever "portrait" of our solar system as seen from the outside. In the course of taking this mosaic consisting of a total of 60 frames, Voyager 1 made several images of the inner solar system from a distance of approximately 4 billion miles and about 32 degrees above the ecliptic plane. Thirty-nine wide angle frames link together six of the planets of our solar system in this mosaic. Outermost Neptune is 30 times further from the sun than Earth. Our sun is seen as the bright object in the center of the circle of frames. The wide-angle image of the sun was taken with the camera's darkest filter (a methane absorption band) and the shortest possible exposure (5 thousandths of a second) to avoid saturating the camera's vidicon tube with scattered sunlight. The sun is not large as seen from Voyager, only about one-fortieth of the diameter as seen from Earth, but is still almost 8 million times brighter than the brightest star in Earth's sky, Sirius. The result of this great brightness is an image with multiple reflections from the optics in the camera. Wide-angle images surrounding the sun also show many artifacts attributable to scattered light in the optics. These were taken through the clear filter with one second exposures. The insets show the planets magnified many times. Narrow-angle images of Earth, Venus, Jupiter, Saturn, Uranus and Neptune were acquired as the spacecraft built the wide-angle mosaic. Jupiter is larger than a narrow-angle pixel and is clearly resolved, as is Saturn with its rings. Uranus and Neptune appear larger than they really are because of image smear due to spacecraft motion during the long (15 second) exposures. From Voyager's great distance Earth and Venus are mere points of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. |
| Date |
06.06.1990 |
|
South Polar View of Miranda
| Title |
South Polar View of Miranda |
| Description |
Uranus' moon Miranda is shown in a computer-assembled mosaic of images obtained Jan. 24, 1986, by the Voyager 2 spacecraft. Miranda is the innermost and smallest of the five major Uranian satellites, just 480 kilometers (about 300 miles) in diameter. Nine images were combined to obtain this full-disc, south-polar view, which shows the varying geologic provinces of Miranda. The bulk of the photo comprises seven high-resolution images from the Voyager closest-approach sequence. Data from more distant, lower-resolution images were used to fill in gaps along the limb. Miranda's surface consists of two strikingly different major types of terrain. One is an old, heavily cratered, rolling terrain with relatively uniform albedo, or reflectivity. The other is a young, complex terrain characterized by sets of bright and dark bands, scarps and ridges features found in the ovoid regions at the top and bottom and in the distinctive "chevron" feature above and to the right of center. Final image processing was done by the U.S. Geological Survey in Flagstaff, Ariz. Special navigational data used to improve Voyager's camera pointing were also used to "control" or register the images in the assembly of the mosaic, the data were generated by means of new techniques developed by JPL's Navigation Ancillary Information Facility. The images were projected onto a global sinusoidal map base. The Voyager Project is managed for NASA by Caltech's Jet Propulsion Laboratory. |
| Date |
05.19.1986 |
|
Epsilon ring of Uranus
| Title |
Epsilon ring of Uranus |
| Description |
Voyager 2 acquired this high-resolution image of the epsilon ring of Uranus on Jan. 23, 1986, from a distance of 1.12 million kilometers (690,000 miles). This clear-filter image from Voyager's narrow-angle camera has a resolution of about 10 km (6 mi). The epsilon ring, approximately 100 km (60 mi) wide at this location, clearly shows a structural variation. Visible here are a broad, bright outer component about 40 km (25 mi) wide, a darker middle region of comparable width, and a narrow, bright inner strip about 15 km (9 mi) wide. The epsilon-ring structure seen by Voyager is similar to that observed from the ground with stellar-occultation techniques. This frame represents the first Voyager image that resolves these features within the epsilon ring. The occasional fuzzy splotches on the outer and inner parts of the ring are artifacts left by the removal of reseau marks (used for making measurements on the image). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.25.1986 |
|
Full-disk view of Titania
| Title |
Full-disk view of Titania |
| Description |
Voyager 2 obtained this full-disk view of Uranus' moon Titania in the early morning hours of Jan. 24, 1986, from a distance of about 500,000 kilometers (300,000 miles). Many circular depressions -- probably impact craters -- are visible in this clear-filter image returned by the Voyager narrow-angle camera. Other bright spots are distinguished by radiating rays and are probably halo craters that mark relatively more recent impacts. Even more interesting are linear troughs (right) that are probably fault canyons. The troughs break the crust in two directions, an indication of some tectonic extension of Titania's crust. These features indicate that this icy satellite has a dynamic, active interior. Titania is about 1,600 km (1,000 mi) in diameter, the resolution of this image is about 9 km (6 mi). The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.25.1986 |
|
Titania - Highest Resolution
…
| Title |
Titania - Highest Resolution Voyager Picture |
| Description |
This is the highest-resolution picture of Titania returned by Voyager 2. The picture is a composite of two images taken Jan. 24, 1986, through the clear filter of Voyager's narrow-angle camera. At the time, the spacecraft was 369,000 kilometers (229,000 miles) from the Uranian moon, the resolution was 13 km (8 mi). Titania is the largest satellite of Uranus, with a diameter of a little more than 1,600 km (1,000 mi). Abundant impact craters of many sizes pockmark the ancient surface. The most prominent features are fault valleys that stretch across Titania. They are up to 1,500 km (nearly 1,000 mi) long and as much as 75 km (45 mi) wide. In valleys seen at right-center, the sunward-facing walls are very bright. While this is due partly to the lighting angle, the brightness also indicates the presence of a lighter material, possibly young frost deposits. An impact crater more than 200 km (125 mi) in diameter distinguishes the very bottom of the disk, the crater is cut by a younger fault valley more than 100 km (60 mi) wide. An even larger impact crater, perhaps 300 km (180 mi) across, is visible at top. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.27.1986 |
|
Titania High-Resolution Colo
…
| Title |
Titania High-Resolution Color Composite |
| Description |
This high-resolution color composite of Titania was made from Voyager 2 images taken Jan. 24, 1986, as the spacecraft neared its closest approach to Uranus. Voyager's narrow-angle camera acquired this image of Titania, one of the large moons of Uranus, through the violet and clear filters. The spacecraft was about 500,000 kilometers (300,000 miles) away, the picture shows details about 9 km (6 mi) in size. Titania has a diameter of about 1,600 km (1,000 mi). In addition to many scars due to impacts, Titania displays evidence of other geologic activity at some point in its history. The large, trenchlike feature near the terminator (day-night boundary) at middle right suggests at least one episode of tectonic activity. Another, basinlike structure near the upper right is evidence of an ancient period of heavy impact activity. The neutral gray color of Titania is characteristic of the Uranian satellites as a whole. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. |
| Date |
01.26.1986 |
|
|
