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S-1 C & BW -62
Voyager 1 looked back at Sat
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12/4/80
| Date |
12/4/80 |
| Description |
Voyager 1 looked back at Saturn on Nov. 16, 1980, four days after the spacecraft flew past the planet, to observe the appearance of Saturn and its rings from this unique perspective. A few of the spokelike ring features discovered by Voyager appear in the rings as bright patches in this image, taken at a distance of 5.3 million kilometers (3.3 million miles) from the planet. Saturn's shadow falls upon the rings, and the bright Saturn crescent is seen through all but the densest portion of the rings. From Saturn, Voyager 1 is on a trajectory taking the spacecraft out of the ecliptic plane, away from the Sun and eventually out of the solar system (by about 1990). Although its mission to Jupiter and Saturn is nearly over (the Saturn encounter ends Dec. 18, 1980), Voyager 1 will be tracked by the Deep Space Network as far as possible in an effort to determine where the influence of the Sun ends and interstellar space begins. Voyager 1's flight path through interstellar space is in the direction of the constellation Ophiuchus. Voyager 2 will reach Saturn on August 25, 1981, and is targeted to encounter Uranus in 1986 and possibly Neptune in 1989. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, California. ##### |
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Voyager 2-N67
These two 591-second exposur
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8/27/89
| Date |
8/27/89 |
| Description |
These two 591-second exposures of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera on Aug. 26, 1989 from a distance of 280,000 kilometers (175,000 miles). The two main rings are clearly visible and appear complete over the region imaged. The time between exposures was one hour and 27 minutes. [During this period the bright ring arcs in the outer bright ring were not visible in either picture (they were unfortunately on the opposite side of the planet for each exposure).] Also visible in this image is the inner faint ring at about 42,000 kilometers (25,000 miles) from the center of Neptune, and the faint band which extends smoothly from the 53,000 kilometer (33,000 miles) ring to roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. These long exposure images were taken while the rings were back-lighted by the sun at a phase angle of 135 degrees. This viewing geometry enhances the visibility of dust and allows fainter, dusty parts of the ring to be seen. The bright glare in the center is due to over-exposure of the crescent of Neptune. The two gaps in the upper part of the outer ring in the image on the left are due to blemish removal in the computer processing. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. ##### |
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Voyager 2-N76
This dramatic view of the cr
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8/29/89
| Date |
8/29/89 |
| Description |
This dramatic view of the crescents of Neptune and Triton was acquired by Voyager 2 approximately 3 days, 6 and one-half hours after its closest approach to Neptune. The spacecraft is now plunging southward at an angle of 48 degrees to the plane of the ecliptic. This direction, combined with the current season of southern summer in the Neptune system, gives this picture its unique geometry. The spacecraft was at a distance of 4.86 million kilometers (3 million miles) from Neptune when these images were shuttered so the smallest detail discernible is approximately 90 kilometers (56 miles). Color was produced using images taken through the narrow-angle camera's clear, orange and green filters. Neptune does not appear as blue from this viewpoint because the forward scattering nature of its atmosphere is more important than its absorption of red light at this high phase angle (134 degrees).The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. |
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Voyager 2
This picture of Neptune was
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4/2/90
| Date |
4/2/90 |
| Description |
This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge, on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager's cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. |
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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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| 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 1981 Voyager 2 image shows the vast Saturn ring system, as well as three small icy satellites and the shadow of a fourth. Saturn is the second largest planet in the Solar System. It has a volume about 760 times that of Earth. Like Jupiter, Uranus, and Neptune, it has no solid surface, but is instead an enormous sphere of gas which gradually compresses into fluid at great depths beneath the clouds. Most of the visible markings are formed in a layer of ammonia ice clouds, which form at a pressure level in Saturn's atmosphere that is comparable to sea-level atmospheric pressure on Earth. Above those clouds, Saturn's atmosphere, like those of the Sun and the other three gas giant planets, is composed almost exclusively of hydrogen and helium. By contrast, Saturn's rings and icy satellites appear to be composed primarily of water ice. Image reprocessed by USGS. (P-43538) |
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Neptune Hurricanes
| title |
Neptune Hurricanes |
| date |
08.24.1989 |
| description |
Voyager 2 sent back this stunning image of storms at work in Neptune's windy atmosphere in August 1989. This photograph of Neptune was reconstructed from two images taken by Voyager 2's narrow-angle camera, through the green and clear filters. The image shows three of the features that Voyager 2 photographed during its Neptune flyby. At the north (top) is the Great Dark Spot, accompanied by bright, white clouds that undergo rapid changes in appearance. To the south of the Great Dark Spot is the bright feature that Voyager scientists nicknamed "Scooter." Still farther south is the feature called "Dark Spot 2," which has a bright core. Each feature moves eastward at a different velocity, so it is only occasionally that they appear close to each other, such as at the time this picture was taken. Voyager 2 is the only spacecraft to visit Neptune. *Image Credit*: NASA |
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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 |
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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 |
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Pale Blue Orb (2)
| title |
Pale Blue Orb (2) |
| date |
09.15.2006 |
| 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, with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus [ http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276 ], for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is approximately 250 kilometers (155 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For, more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ] . Credit: NASA/JPL/Space Science Institute |
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Charon Discovery Image
| 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 |
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Neptune Great Dark Spot in H
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| title |
Neptune Great Dark Spot in High Resolution |
| date |
08.30.1999 |
| description |
This photograph shows the last face-on view of the Great Dark Spot that Voyager will make with the narrow angle camera. The image was shuttered 45 hours before closest approach at a distance of 2.8 million kilometers (1.7 million miles). The smallest structures that can be seen are of an order of 50 kilometers (31 miles). The image shows feathery white clouds that overlie the boundary of the dark and light blue regions. The pinwheel (spiral) structure of both the dark boundary and the white cirrus suggest a storm system rotating counterclockwise. Periodic small scale patterns in the white cloud, possibly waves, are short lived and do not persist from one Neptunian rotation to the next. This color composite was made from the clear and green filters of the narrow-angle camera. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. *Image Credit*: JPL |
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Triton - Detail of Dark and
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| title |
Triton - Detail of Dark and Light Material |
| date |
08.24.1989 |
| description |
Voyager 2 acquired this black and white image of Triton, Neptune's largest satellite, during the night of Aug. 24-25, 1989. Triton's limb cuts obliquely across the middle of the image. The field of view is about 1,000 km (600 miles) across. Three irregular dark areas, surrounded by brighter material, dominate the image. Low-lying material with intermediate albedo occupies the central area, and fresh craters occur along the right margin. Sub-parallel alignment of linear patches of dark material shown in the lower and left part of the image suggests that the patches are structurally controlled. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. *Image Credit*: JPL |
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A Parting Shot
| title |
A Parting Shot |
| date |
01.29.1996 |
| description |
This false color photograph of Neptune was made from Voyager 2 images taken through three filters: blue, green, and a filter that passes light at a wavelength that is absorbed by methane gas. Thus, regions that appear white or bright red are those that reflect sunlight before it passes through a large quantity of methane. The image reveals the presence of a ubiquitous haze that covers Neptune in a semitransparent layer. Near the center of the disk, sunlight passes through the haze and deeper into the atmosphere, where some wavelengths are absorbed by methane gas, causing the center of the image to appear less red. Near the edge of the planet, the haze scatters sunlight at higher altitude, above most of the methane, causing the bright red edge around the planet. By measuring haze brightness at several wavelengths, scientists are able to estimate the thickness of the haze and its ability to scatter sunlight. The image is among the last full disk photos that Voyager 2 took before beginning its endless journey into interstellar space. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. *Image Credit*: JPL |
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Neptune's Stormy Disposition
| title |
Neptune's Stormy Disposition |
| date |
08.11.1998 |
| description |
Using powerful ground-and space-based telescopes, scientists have obtained a moving look at some of the wildest, weirdest weather in the solar system. Combining simultaneous observations of Neptune made with the Hubble Space Telescope and NASA's Infrared Telescope Facility on Mauna Kea, Hawaii, a team of scientists led by Lawrence A. Sromovsky of the University of Wisconsin-Madison has captured the most insightful images to date of a planet whose blustery weather -- monster storms and equatorial winds of 900 miles per hour -- bewilders scientists. The weather on Neptune, the eighth planet from the sun, is an enigma to begin with. The mechanism that drives its near-supersonic winds and giant storms has yet to be determined. On Earth, weather is driven by energy from the sun as it heats the atmosphere and oceans. On Neptune, the sun is 900 times dimmer and scientists have yet to understand how Neptune's weather-generating machinery can be so efficient. "It's an efficient weather machine compared to Earth," said Sromovsky. "It seems to run on almost no energy." In an effort to dissect the distant planet's atmosphere and monitor its bizarre weather, Sromovsky and his colleagues obtained a series of measurements and images over the span of three of Neptune's rotations. From those observations, Sromovsky said it is possible to measure Neptune's circulation and view a "strange menagerie of variable, discrete cloud features and zonal bands" of weather. Moreover, the new observations enabled Sromovsky's team to probe some of the deeper features of the atmosphere and to map Neptune's cloud tops. "We can show some clouds are higher than others, that altitudes vary," he said. Knowing something about the topography of Neptune's clouds, provides a direct way to measure Neptune's powerful winds. A looming mystery, he said, is the fate of huge dark spots, possibly giant storms. When the planetary probe Voyager visited Neptune in 1989, it detected the Great Dark Spot, a pulsating feature nearly the size of the Earth itself. Two years ago, Hubble observations showed the spot had disappeared, and that another, smaller spot had emerged. But instead of growing to a large-scale storm like the Great Dark Spot, the new spot appears to be trapped at a fixed latitude and may be declining in intensity, said Sromovsky, a senior scientist at UW-Madison's Space Science and Engineering Center. "They behave like storms, and the Great Dark Spot was an exaggerated features we haven't seen on any other planet. They seem to come and go, and rather than an exciting development of these dark spots, they dissipate." Another strange aspect of the distant planet's weather are distinct bands of weather that run parallel to the Neptunian equator. The weather bands encircle the planet and, in some respects, may be similar to the equatorial region of the Earth where tropical heat provides abundant energy to make clouds. "We can see regions of latitude where Neptune, consistently generates bright clouds," said Sromovsky. The regions are both above and below the planet's equator, but he added that it was uncertain what their explanation is in terms of atmospheric circulation. Sromovsky said that compared to the look provided by the Voyager spacecraft, Neptune is a different place: "The character of Neptune is different from what it was at the time of Voyager. The planet seems stable, yet different." Sromovsky's Hubble observations were made with Wide Field Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer. The different instruments allowed observations to be made in a variety of wavelengths, each providing a different set of information about Neptune's clouds, their structures and how they circulate. *Image Credit*: NASA |
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Triton
| title |
Triton |
| date |
08.23.1989 |
| description |
The smallest features that can be seen in this false color image of Neptune's largest satellite, Triton, are about 47 km (29 miles) across. The image, taken by Voyager 2 early in the morning of Aug. 23, 1989, is a composite of three images taken through ultraviolet, green, and violet filters. The image offers an example of the kinds of puzzles scientists face on the eve of an encounter: Mottling in the bright southern hemisphere may be the result of topography, if Triton's crust is predominantly water ice, which is rigid at Triton's surface temperature. Alternatively, the mottling could be due to markings on a smooth surface, if the crust is composed of nitrogen, carbon monoxide, or methane ice, since they are soft at the same temperature. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. *Image Credit*: NASA |
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Neptune's Rings
| title |
Neptune's Rings |
| date |
08.24.1989 |
| description |
This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to overexposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. *Image Credit*: NASA |
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Neptune and Triton
| title |
Neptune and Triton |
| date |
08.28.1989 |
| description |
This dramatic view of the crescents of Neptune and Triton was acquired by Voyager 2 approximately 3 days, 6 and one-half hours after its closest approach to Neptune (north is to the right). The encounter put the spacecraft on a couse plunging southward at an angle of 48 degrees to the plane of the ecliptic. This direction, combined with the current season of southern summer in the Neptune system, gives this picture its unique geometry. The spacecraft was at a distance of 4.86 million kilometers (3 million miles) from Neptune when these images were taken so the smallest detail discernible is approximately 90 kilometers (56 miles). Color was produced using images taken through the narrow-angle camera's clear, orange and green filters. Neptune does not appear as blue from this viewpoint because the forward scattering nature of its atmosphere is more important than its absorption of red light at this high phase angle (134 degrees). *Image Credit*: NASA |
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Neptune
| title |
Neptune |
| date |
08.21.1989 |
| description |
This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge, on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager's cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen. *Image Credit*: NASA |
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Neptune Clouds
| title |
Neptune Clouds |
| date |
08.25.1989 |
| description |
This Voyager 2 high resolution color image, taken 2 hours before closest approach, provides obvious evidence of vertical relief in Neptune's bright cloud streaks. These clouds were observed at a latitude of 29 degrees north near Neptune's east terminator. The linear cloud forms are stretched approximately along lines of constant latitude and the Sun is toward the lower left. The bright sides of the clouds which face the Sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun. Shadows can be seen on the side opposite the sun. These shadows are less distinct at short wavelengths (violet filter) and more distinct at long wavelengths (orange filter). This can be understood if the underlying cloud deck on which the shadow is cast is at a relatively great depth, in which case scattering by molecules in the overlying atmosphere will diffuse light into the shadow. Because molecules scatter blue light much more efficiently than red light, the shadows will be darkest at the longest (reddest) wavelengths, and will appear blue under white light illumination. The resolution of this image is 11 kilometers (6.8 miles per pixel) and the range is only 157,000 kilometers (98,000 miles). The width of the cloud streaks range from 50 to 200 kilometers (31 to 124 miles), and their shadow widths range from 30 to 50 kilometers (18 to 31 miles). Cloud heights appear to be of the order of 50 kilometers (31 miles). *Image Credit*: NASA Jet Propulsion Laboratory |
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Full-Disk Neptune
| title |
Full-Disk Neptune |
| date |
08.20.1989 |
| description |
This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge, on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager's cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen. *Image Credit*: NASA |
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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 |
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Montage of Neptune and Trito
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| Title |
Montage of Neptune and Triton |
| Full Description |
This computer generated montage shows Neptune as it would appear from a spacecraft approaching Triton, Neptune's largest moon at 2706 km (1683 mi) in diameter. The wind and sublimation eroded south polar cap of Triton is shown at the bottom of the Triton image, a cryovolcanic terrain at the upper right, and the enigmatic "cantaloupe terrain" at the upper left. Triton's surface is mostly covered by nitrogen frost mixed with traces of condensed methane, carbon dioxide, and carbon monoxide. The tenuous atmosphere of Triton, though only about one hundredth of one percent of Earth's atmospheric density at the surface, is thick enough to produce wind-deposited streaks of dark and bright materials of unknown composition in the south polar cap region. The southern polar cap was sublimating at the time of the Voyager 2 flyby, as indicated by the irregular and eroded appearance of the edge of the cap. |
| Date |
01/06/1990 |
| NASA Center |
Jet Propulsion Laboratory |
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Neptune and Tritron
| Title |
Neptune and Tritron |
| Full Description |
This image was returned by the Voyager 2 spacecraft on July 3, 1989, when it was 76 million kilometers (47 million miles) from Neptune. The planet and its largest satellite, Triton, are captured in the field of view of Voyager's narrow-angle camera through violet, clear and orange filters. Triton appears in the lower right corner at about 5 o'clock relative to Neptune. Measurements from Voyager images show Triton to be between 1,400 and 1,800 kilometers (about 870 to 1,100 miles) in radius with a surface that is about as bright as freshly fallen snow. Because Triton is barely resolved in current narrow-angle images, it is too early to see features on its surface. Scientists believe Triton has at least a small atmosphere of methane and possibly other gases. During its closest approach to Triton on August 25, 1989, Voyager provided high-resolution views of the moon's icy surface and reveal whether Triton's atmosphere has clouds. JPL manages the Voyager Project for NASA's Office of Space Science and Applications, Washington, DC. |
| Date |
07/27/1989 |
| NASA Center |
Jet Propulsion Laboratory |
|
Neptune Full Disk View
| Title |
Neptune Full Disk View |
| Full Description |
This picture of Neptune was produced from the last whole planet images taken through the green and orange filters on the Voyager 2 narrow angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge, on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager's cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen. Years later, when the Hubble telescope was focused on the planet, these atmospheric features had changed, indicating that Neptune's atmosphere is dynamic. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications, Washington, DC. |
| Date |
04/02/1990 |
| NASA Center |
Jet Propulsion Laboratory |
|
Detail of Triton
| Title |
Detail of Triton |
| Full Description |
This color photo of Neptune's large satellite Triton was obtained on Aug. 24 1989 at a range of 530,000 kilometers (330,000 miles). The resolution is about 10 kilometers (6.2 miles), sufficient to begin to show topographic detail. The image was made from pictures taken through the green, violet and ultraviolet filters. In this technique, regions that are highly reflective in the ultraviolet appear blue in color. In reality, there is no part of Triton that would appear blue to the eye. The bright southern hemisphere of Triton, which fills most of this frame, is generally pink in tone as is the even brighter equatorial band. The darker regions north of the equator also tend to be pink or reddish in color. JPL manages the Voyager project for NASA's Office of Space Science, Washington, DC. |
| Date |
08/25/1998 |
| 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 |
|
Global Color Mosaic of Trito
…
| Title |
Global Color Mosaic of Triton |
| Full Description |
Global color mosaic of Triton, taken in 1989 by Voyager 2 during its flyby of the Neptune system. Color was synthesized by combining high- resolution images taken through orange, violet, and ultraviolet filters, these images were displayed as red, green, and blue images and combined to create this color version. With a radius of 1,350 (839 mi), about 22% smaller than Earth's moon, Triton is by far the largest satellite of Neptune. It is one of only three objects in the Solar System known to have a nitrogen-dominated atmosphere (the others are Earth and Saturn's giant moon, Titan). Triton has the coldest surface known anywhere in the Solar System (38 K, about -391 degrees Farenheit), it is so cold that most of Triton's nitrogen is condensed as frost, making it the only satellite in the Solar System known to have a surface made mainly of nitrogen ice. The pinkish deposits constitute a vast south polar cap believed to contain methane ice, which would have reacted under sunlight to form pink or red compounds. The dark streaks overlying these pink ices are believed to be an icy and perhaps carbonaceous dust deposited from huge geyser-like plumes, some of which were found to be active during the Voyager 2 flyby. The bluish-green band visible in this image extends all the way around Triton near the equator, it may consist of relatively fresh nitrogen frost deposits. The greenish areas include what is called the cataloupe terrain, whose origin is unknown, and a set of "cryovolcanic" landscapes apparently produced by icy-cold liquids (now frozen) erupted from Triton's interior. |
| Date |
05/01/1980 |
| 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 |
|
Hubble Space Telescope Obser
…
| Title |
Hubble Space Telescope Observations of Neptune |
|
Hubble Discovers New Dark Sp
…
| Title |
Hubble Discovers New Dark Spot on Neptune |
|
Hubble Discovers New Dark Sp
…
| Title |
Hubble Discovers New Dark Spot on Neptune |
|
Hubble Discovers Dark Cloud
…
| Title |
Hubble Discovers Dark Cloud in the Atmosphere of Uranus |
|
A89-7004
Photographer : JPL Range : 8
…
8/19/89
| Description |
Photographer : JPL Range : 8.6 million kilometers (5.3 million miles) The Voyager took this 61 second exposure through the clear filter with the narrow angle camera of Neptune. The Voyager cameras were programmed to make a systematic search for faint ring arcs and new satellites. The bright upper corner of the image is due to a residual image from a previous long exposure of the planet. The portion of the arc visible here is approximately 35 degrees in longitudinal extent, making it approximately 38,000 kilometers (24,000 miles) in length, and is broken up into three segments separated from each other by approximately 5 degrees. The trailing edge is at the upper right and has an abrupt end while the leading edge seems to fade into the background more gradually. This arc orbits very close to one of the newly discovered Neptune satellites, 1989N4. Close-up studies of this ring arc will be carried out in the coming days which will give higher spatial resolution at different lighting angles. (JPL Ref: P-34617) |
| Date |
8/19/89 |
|
A89-7012
Photographer : JPL Range : 4
…
8/22/89
| Description |
Photographer : JPL Range : 4 million km (2.5 million miles) Already-intriquing patterns of unknown origin appear on the surgace of Neptune's largest satellite, Trition, in this image from Voyager 2. Voyager images show that Trition's diameter is about 2,720 km (1,690 miles), and that it is one of the brightest objects in the solar system, reflecting about 70 percent of the sunlight that strikes it. THis is the hemisphere of Triton that always faces away from Neptune. The south pole is near the botton of the image. Triton's rotation axis is tilted so that the latitude at the center of the disk is 55 degrees south. Dark regions at the top of the disk extend from roughly the equator to beyond 20 degrees north. The margin between the bright and dark regions varies with longitude around the satellite. The gray, featureless area just to the right of the center of the disk is due to a reseau (reticule mark) in the camera. |
| Date |
8/22/89 |
|
A89-7024
Photographer : JPL P-34679 R
…
8/23/89
| Description |
Photographer : JPL P-34679 Range : 2 million km. ( 1.2 million miles ) In this Voyager 2, wide-angle image, the two main rings of Neptune can be clearly seen. In the lower part of the frame, the originally-announced ring arc, consisting of three distinct features, is visible. This feature covers about 35 degrees of longitude and has yet to be radially resolved in Voyager Images. from higher resolution images it is known that this region contains much more material than the diffuse belts seen elsewhere in its orbit, which seem to encircle the planet. This is consistent with the fact that ground-based observations of stellar occultations by the rings show them to be very broken and clumpy. The more sensitive, wide-angle camera is revealing more widely distributed but fainter material. Each of these rings of material lies just outside of the orbit of a newly discovered moon. One of these moons, 1989N2, may be seen in the upper right corner. The moon is streaked by its orbital motion, whereas the stars in the frame are less smeared. the dark area around the bright moon and star are artifacts of the processing required to bring out the faint rings. |
| Date |
8/23/89 |
|
A89-7037
Photographer: JPL P-34707 Ra
…
8/26/89
| Description |
Photographer: JPL P-34707 Range: 720,000 kilometers (446,400 miles) The Voyager spacecraft took this picture after closest approach to Neptune using the clear filter of the wide-angle camera with an exposure time of 255 seconds. The view back towards Neptune at a phase angle of 135 _ found the two known rings to be five to ten times brighter than seen in backscattering during Voyager approach at a much lower phase angle. This brightness increase implies a large percentage of microscopic particles within the rings. Although the dominant arc-like clump of the outer ring is not seen here, the inner ring appears brighter than the outer ring at the longitudes seen in this image. A faint sheet of material is also revealed that extends from the faint ring at a radius of 53,200 kilometers (33,000 miles). A new and even fainter ring was also discovered in this image at about 41,000 kilometers (25,400 miles), seen running from the lower left corner to about one-third the way across the top of the frame. This ring is quite broad, about 2,500 kilometers (1,550 miles) in radial width. In contrast to the two previously discovered rings, this feature is quite diffuse and has no well defined radial boundaries. |
| Date |
8/26/89 |
|
A89-7058
Voyager II Imagery, Neptune.
…
8/24/89
| Description |
Voyager II Imagery, Neptune. This bulls-eye view of Neptune's small dark spot (D2) was obtained by Voyager 2's narrow-angle camera , when Neptune was within 1.1 million km (680,000 miles) of the planet. The smallest structures that can be seen are 20 km (12 miles) across. This unplanned photograph was obtained when the infrared spectrograph was mapping the the highest-resolution view of the feature taken during the flyby. Banding surrounding the feature indicates unseen strong winds, while structues within the bright spot suggest both active upwelling of clouds and rotation about the center. A rotation rate has not yet been measured, but the v-shaped structure near the right edge of the bright area indicates that the spot rotates clockwise. Unlike the Great Red Spot on Jupiter, which rotates counterclockwise, if the D2 spot on Neptune rotates clockwise, the material will be descending in the dark oval region. The fact that infrared data will yield temperature information about the region above the clouds makes this observation especially valuable. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applicaitons. (JPL ref: P-34749 Voyager N-71) taken during the flyby. Banding surrounding the feature indicates unseen strong winds, while structures within the bright spot suggest both active upwelling of clouds and rotation about the center. A rotation rate has not yest been measured, but the Vv-sphped |
| Date |
8/24/89 |
|
AC89-7013
Photographer : JPL P-34648 T
…
8/23/89
| Description |
Photographer : JPL P-34648 This photograph of Neptune was reconstructed from two images taken by Voyager 2's narrow angle camera, through the green and clear filters. the image shows three of the features that Voyager 2 has been photographing during recent weeks. At the north ( top ) is the Great Dark Spot, accompanied by bright, white clouds that undergo rapid changes in appearance. to the south of the Great Dark Spot is the bright feature that Voyager scientists have nicknamed "Scooter." Still farther south is the feature called " Dark Spot 2," which has a bright core. Each feature moves eastward at a different at a different velocity, so it is only occasionally that they appear close to each other, such as at the time this picture was taken. |
| Date |
8/23/89 |
|
AC89-7044
Photographer : JPL Range : 3
…
8/22/89
| Description |
Photographer : JPL Range : 30 million km. ( 18.6 million miles ) P-34628 C The south pole of Neptune is at the center of this polar projection made from five color images taken by Voyager 2 over the course of one Neptunian day-- about 18 hours. Latitude lines are concentric circles, and the outer circle is at about 15 degrees north latitude. Cloud paterns are organized by the planet's rotation and are generally concentric with the pole . Oval storms, which drift in longitude at relative speeds up to 400 miles an hour, disrupt the circular symmetry. The color composite was made from black and white frames through the Voyager narrow angle camera's clear, orange, and green filters. |
| Date |
8/22/89 |
|
AC89-7055
Vouager II Imagery, Neptune:
…
8/25/89
| Description |
Vouager II Imagery, Neptune: This is one of the most detailed views of the surface of Triton taken by Voyager 2 on its flyby of the large satellite of Neptune early in the morning of August 25, 1989. The picture was stored on the tape recorder and relayed to Earth later. Taken from a distanT ce of only 40,000 km (25, 000 miles), the frame is about 220 kilometers (140 miles) across and shows details as small as 750 meters (0.5 miles). Most of the area is covered by a peculiar landscape of roughly circular depressions separated by rugged ridges. This type of terrain, which covers large tracts of Triton's northern hemisphere, is unlike anything seen elsewhere in the solar system. The depressions are probably not impact craters: They are too similar in size and too regularly spaced. Their origin is still unknown, but may involve local melting and collapse of the icy surface. A conspicuous set of grooves and ridges cuts across the landscape, indicating fracturing and deformation of Triton's surface. The rarity of impact craters suggests a young surface by solar-system standards, probably less than a few billion years old. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. (JPL ref: P-34722 Voyager N-60 ) |
| Date |
8/25/89 |
|
Jupiter, its great Red Spot
…
| Name of Image |
Jupiter, its great Red Spot three of its four largest satellites |
| Date of Image |
1979-02-05 |
| Full Description |
On February 5, 1979, Voyager 1 made its closest approach to Jupiter since early 1974 and 1975 when Pioneers 10 and 11 made their voyages to Jupiter and beyond. Voyager 1 completed its Jupiter encounter in early April, after taking almost 19,000 pictures and recording many other scientific measurements. Although astronomers had studied Jupiter from Earth for several centuries, scientists were surprised by many of Voyager 1 and 2's findings. They now understand that important physical, geological, and atmospheric processes go on that they had never observed from Earth. Discovery of active volcanism on the satellite Io was probably the greatest surprise. It was the first time active volcanoes had been seen on another body in the solar system. Voyager also discovered a ring around Jupiter. Thus Jupiter joins Saturn, Uranus, and Neptune as a ringed planet -- although each ring system is unique and distinct from the others. |
|
Voyager photographs of Neptu
…
| Name of Image |
Voyager photographs of Neptune |
| Date of Image |
1989-08-25 |
| Full Description |
Voyager 2 was the first spacecraft to observe the planet Neptune and its two satellites: Triton, the largest, and Nereid. The most obvious feature of the planet is its blue color, the result of methane in the atmosphere. Research continues on Neptune's two largest satellites and the additional six that were discovered by Voyager 2's investigation. These images represent the most complete set of full disk Neptune images that the spacecraft will acquire. |
|
Titania's Trenches
| Title |
Titania's Trenches |
| Explanation |
British astronomer Sir William Herschel [ http://star.arm.ac.uk/history/herschel.html ] discovered Titania and Oberon in January of 1787. He wasn't reading Shakespeare's [ http://the-tech.mit.edu/Shakespeare/works.html ]"A Midsummer Night's Dream" though, he was making the first telescopic observations of moons of the planet Uranus [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/uranus.html ] (a planet which he himself discovered in 1781 [ http://www-groups.dcs.st-and.ac.uk/~history/ HistTopics/Neptune_and_Pluto.html ]). In January of 1986, nearly 200 years later, NASA's robot explorer Voyager 2 became the only spacecraft to visit the remote Uranian [ http://antwrp.gsfc.nasa.gov/apod/ap990531.html ] system [ http://antwrp.gsfc.nasa.gov/apod/ap971103.html ]. Above is Voyager's highest resolution picture of Titania [ http://photojournal.jpl.nasa.gov/cgi-bin/ PIAGenCatalogPage.pl?PIA00039 ], Uranus' largest moon. The picture is a composite of two images recorded from a distance of 229,000 miles. The icy, rocky world [ http://antwrp.gsfc.nasa.gov/apod/ap960304.html ] is seen to be covered with impact craters. A prominent system of fault valleys, some nearly 1,000 miles long, is visible as trench-like features near the terminator (shadow line). Deposits of highly reflective material which may represent frost can be seen along the sun-facing valley walls. The large impact crater near the top, known as Gertrude [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/uranus/titacrat.html ], is about 180 miles across. At the bottom the 60 mile wide fault valley, Belmont Chasma [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/uranus/titachas.html ], cuts into crater Ursula. Titania itself [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/wall/titania.html ] is 1,000 miles in diameter. |
|
Triton: Neptune's Largest Mo
…
| Title |
Triton: Neptune's Largest Moon |
| Explanation |
In October of 1846, William Lassell [ http://en.wikipedia.org/wiki/William_Lassell ] was observing the newly discovered planet Neptune [ http://www.seds.org/nineplanets/nineplanets/neptune.html ]. He was attempting to confirm his observation, made just the previous week, that Neptune [ http://en.wikipedia.org/wiki/Neptune ] had a ring. But this time he discovered that Neptune had a satellite as well. Lassell soon proved that the ring was a product of his new telescope's distortion, but the satellite Triton [ http://www.seds.org/nineplanets/nineplanets/triton.html ] remained. The above picture [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vg2_p34764.html ] of Triton [ http://en.wikipedia.org/wiki/Triton_%28moon%29 ] was taken in 1989 by the only spacecraft ever to pass Triton [ http://antwrp.gsfc.nasa.gov/apod/ap950805.html ]: Voyager [ http://antwrp.gsfc.nasa.gov/apod/ap020831.html ] 2. Voyager 2 found fascinating terrain [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/triton_close.txt ], a thin atmosphere, and even evidence for ice volcanoes [ http://antwrp.gsfc.nasa.gov/apod/ap010629.html ] on this world of peculiar orbit and spin. Ironically, Voyager 2 also confirmed the existence of complete thin rings [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vg2_1135023.html ] around Neptune - but these would have been quite invisible [ http://www.youtube.com/watch?v=OQWxIrSRDQQ ] to Lassell! |
|
Dark Spots on Neptune
| Title |
Dark Spots on Neptune |
| Explanation |
Neptune has spots. The Solar System [ http://space.jpl.nasa.gov/ ]'s outermost gas giant shows a nearly uniform blue hue created by small amounts of methane [ http://scifun.chem.wisc.edu/chemweek/methane/methane.html ] drifting in a thick atmosphere of nearly colorless hydrogen [ http://pearl1.lanl.gov/periodic/elements/1.html ] and helium [ http://pearl1.lanl.gov/periodic/elements/2.html ]. Dark spots do appear, however, that are anti-cyclones [ http://library.thinkquest.org/C003765/english/adv/lpsystems.html ]: large high-pressure systems that swirl in Neptune's cold cloud tops [ http://antwrp.gsfc.nasa.gov/apod/ap991005.html ]. Two dark spots are visible in the above picture [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA01142 ] taken by the robot Voyager 2 spacecraft [ http://vraptor.jpl.nasa.gov/voyager/vgrfaqs.html ] in 1989: an Earth [ http://antwrp.gsfc.nasa.gov/apod/ap001127.html ]-sized Great Dark Spot [ http://pds.jpl.nasa.gov/planets/captions/neptune/gdspot2.htm ] located on the far left, and Dark Spot 2 located near bottom. A bright cloud dubbed Scooter [ http://pds.jpl.nasa.gov/planets/captions/neptune/scooter.htm ] accompanies the Great Dark Spot. Recent computer simulations [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001Icar..151..275S ] indicate that scooters are methane clouds that might commonly be found near dark spots. Subsequent images [ http://antwrp.gsfc.nasa.gov/apod/ap960507.html ] of Neptune [ http://www.solarviews.com/eng/neptune.htm ] by the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ] in 1994 indicated that both of these dark spots had dissipated [ http://antwrp.gsfc.nasa.gov/apod/ap960508.html ], but another had been created [ http://hubble.stsci.edu/news_.and._views/pr.cgi.1995+21 ]. |
|
Uranus: The Tilted Planet
| Title |
Uranus: The Tilted Planet |
| Explanation |
Uranus is the third largest planet in our Solar System [ http://www.nineplanets.org/overview.html ] after Jupiter [ http://antwrp.gsfc.nasa.gov/apod/jupiter.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap010826.html http://www.solarviews.com/eng/saturn.htm ]. Uranus [ http://www.nineplanets.org/uranus.html ] is composed mostly of rock and ices, but with a thick hydrogen [ http://chemlab.pc.maricopa.edu/periodic/h.html ] and helium [ http://antwrp.gsfc.nasa.gov/apod/ap010120.html ] atmosphere. The blue hue of Uranus' atmosphere arises from the small amount of methane [ http://scifun.chem.wisc.edu/chemweek/methane/methane.html ] which preferentially absorbs red light. This picture [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA01360 ] was snapped by the Voyager 2 spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/voyager.html ] in 1986 - the only spacecraft ever to visit Uranus. Uranus [ http://antwrp.gsfc.nasa.gov/apod/uranus.html ] has many moons [ http://antwrp.gsfc.nasa.gov/apod/ap990531.html ] and a ring system [ http://antwrp.gsfc.nasa.gov/apod/ap971126.html ]. Uranus, like Venus [ http://antwrp.gsfc.nasa.gov/apod/venus.html ], has a rotation axis that is greatly tilted and sometimes points near the Sun. It remains an astronomical mystery why Uranus' axis [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1991LPIP...22...59S ] is so tilted. Uranus and Neptune [ http://antwrp.gsfc.nasa.gov/apod/neptune.html ] are quite similar: Uranus is slightly larger but less massive. |
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