|
|
OUTWARD BOUND VOYAGER--A Tit
…
| Description |
OUTWARD BOUND VOYAGER--A Titan-Centaur launch vehicle hurls Voyager 1 from Cape Canaveral toward its rendezvous with Jupiter and Saturn. The launch took place at 5:56 a.m. (PDT) September 5, 1977. Voyager 1 followed Voyager 2 away from Earth, but by the time they reach Jupiter it will be four months ahead of Voyager 2. Voyager 1 will reach Saturn nine months ahead of Voyager 2. The Voyager project is managed by Caltech's Jet Propulsion Laboratory for NASA's Office of Space Science. |
|
Seen here is a full-scale mo
…
| Description |
Seen here is a full-scale model of one of the twin Voyager spacecraft, which was sent to explore the giant outer planets in our solar system. Voyager 2 was launched August 20, 1977 followed by the launch of Voyager 1 sixteen days later. Both spacecraft visited Jupiter and Saturn with Voyager 2 continuing its journey to Uranus and Neptune. In spring 1990, Voyager 2 transmitted images looking back across the span of the entire solar system. Both Voyagers continue to explore interstellar space. |
|
S-1 C & BW -62
Voyager 1 looked back at Sat
…
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. ##### |
|
Voyager 2-N67
These two 591-second exposur
…
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. ##### |
|
Voyager 2-N76
This dramatic view of the cr
…
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. |
|
Voyager 2-N77
Voyager 2 obtained this high
…
8/29/89
| Date |
8/29/89 |
| Description |
Voyager 2 obtained this high-resolution color image of Neptune's large satellite Triton during its close flyby on Aug. 25, 1989. Approximately a dozen individual images were combined to produce this comprehensive view of the Neptune-facing hemisphere of Triton. Fine detail is provided by high-resolution, clear-filter images, with color information added from lower-resolution frames. The large south polar cap at the bottom of the image is highly reflective and slightly pink in color, it may consist of a slowly evaporating layer of nitrogen ice deposited during the previous winter. From the ragged edge of the polar cap northward the satellite's face is generally darker and redder in color. This coloring may be produced by the action of ultraviolet light and magnetospheric radiation upon methane in the atmosphere and surface. Running across this darker region, approximately parallel to the edge of the polar cap, is a band of brighter white material that is almost bluish in color. The underlying topography in this bright band is similar, however to that in the darker, redder regions surrounding it. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. ##### |
|
Voyager 2
This picture of Neptune was
…
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. |
|
Galileo and Cassini Image: T
…
Two Giant Plumes on Io ,Two
…
3/29/01
| Date |
3/29/01 |
| Description |
Two Giant Plumes on Io ,Two tall volcanic plumes and the rings of red material they have deposited onto surrounding surface areas appear in images taken of Jupiter's moon Io by NASA's Galileo and Cassini spacecraft in late December 2000 and early January 2001. One plume, from the volcano Pele, shoots upward nearly 400 kilometers (250 miles) from the surface near Io's equator. The plume has been active for at least four years and, until now, had been far larger than any other plume seen on Io. The images also show a second plume about the same size, closer to Io's north pole. This plume had never been seen before. It is associated with a fresh eruption from the Tvashtar Catena volcanic area. The observations were made during joint studies of the Jupiter system while Cassini was passing Jupiter on its way to Saturn. Galileo passed closer to Io for higher-resolution images, and Cassini acquired images at ultraviolet wavelengths, better for detecting active volcanic plumes. The Cassini ultraviolet images, upper right, reveal two gigantic, actively erupting plumes of gas and dust. Near the equator, just the top of Pele's plume is visible where it projects into sunlight. None of it would be illuminated if it were less than 240 kilometers (150 miles) high. These images indicate a total height for Pele of 390 kilometers (242 miles). The Cassini image at far right shows a bright spot over Pele's vent. Although the Pele hot spot has a high temperature, silicate lava cannot be hot enough to explain a bright spot in the ultraviolet, so the origin of this bright spot is a mystery, but it may indicate that Pele was unusually active when the picture was taken. Also visible is a plume near Io's north pole. Although 15 active plumes over Io's equatorial regions have been detected in hundreds of images from NASA's Voyager and Galileo spacecraft, this is the first image ever acquired of an active plume over a polar region of Io. The plume projects about 150 kilometers (about 90 miles) over the limb, the edge of the globe. If it were erupting from a point on the limb, it would be only slightly larger than a typical Ionian plume, but the image does not reveal whether the source is actually at the limb or beyond it, out of view. A distinctive feature in Galileo images since 1997 has been a giant red ring of Pele plume deposits about 1,400 kilometers (870 miles) in diameter. The Pele ring is seen again in one of the new Galileo images, lower left. When the new Galileo images were returned this month, scientists were astonished to see a second giant red ring on Io, centered around Tvashtar Catena at 63 degrees north latitude. (To see a comparison from before the ring was deposited, see images PIA-01604 or PIA-02309.) Tvashtar was the site of an active curtain of high-temperature silicate lava imaged by Galileo in November 1999 and February 2000 (image PIA- 02584). The new ring shows that Tvashtar must be the vent for the north polar plume imaged by Cassini from the other side of Io. This means the plume is actually about 385 kilometers (239 miles) high, just like Pele. The uncertainty in estimating the height is about 30 kilometers (19 miles), so the plume could be anywhere from 355 to 415 kilometers (221 to 259 miles) high. If this new plume deposit is just one millimeter (four one- hundredths of an inch) thick, then the eruption produced more ash than the 1980 eruption of Mount St. Helens in Washington. NASA recently approved a third extension of the Galileo mission, including a pass over Io's north pole in August 2001. The spacecraft's trajectory will pass directly over Tvashtar at an altitude of 200 kilometers (124 miles). Will Galileo fly through an active plume? That depends on whether this eruption is long- lived like Pele or brief, and it also depends on how high the plume is next August. Two Pele-sized plumes are inferred to have erupted in 1979 during the four months between Voyager 1 and Voyager 2 flybys, as indicated by new Pele-sized rings in Voyager 2 images. Those eruptions, both from high-latitude locations, were shorter-lived than Pele, but their actual durations are unknown. In May, Galileo will get another, more distant look at Tvashtar. It has been said that Io is the heartbeat of the jovian magnetosphere. The two giant plumes evidenced in these images may have had significant effects on the types, density and distribution of neutral and charged particles in the Jupiter system during the joint observations of the system by Galileo and Cassini from November 2000 to March 2001. These Cassini images were acquired on Jan. 2, 2001, except for the frame at the far right, which was acquired a day earlier. The Galileo images were acquired on Dec. 30 and 31, 2000. Cassini was about 10 million kilometers (6 million miles) from Io, 10 times farther than Galileo. More information about the Cassini and Galileo joint observations of the Jupiter system is available online at http://www.jpl.nasa.gov/jupiterflyby . Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Cassini missions for NASA's Office of Space Science, Washington, D.C. |
|
NASA TV's This Week @NASA, J
…
During a special ceremony Mi
…
07/12/10
| Description |
During a special ceremony Michoud employees were honored by VIPs for building the final external tank and were recognized for the successful delivery over 37 years of 134 ETs to the Space Shuttle Program.* A full house crowd at the Langley Research Center's Pearl Young Theater heard Jaiwon Shin, NASA's Associate Administrator for Aeronautics, laud the quality and depth of work being done at the Center.* A new NASA video game is offering some daunting challenges to virtual space travelers. * A banner with patches featuring various aspects of operations at Yellowstone National Park was aboard space shuttle Endeavour on the STS-130 mission to the International Space Station last February. * For nearly 33 years, Voyager 2 has returned data about the giant outer planets, making important discoveries like Neptune's Great Dark Spot and its 1,000-mph winds. On June 28, Voyager 2 reached an operations milestone - 12,000 days. |
| Date |
07/12/10 |
|
| 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 Voyager 2 photograph of Titan, taken August 23, 1981 from a range of 2.3 million kilometers (1.4 million miles), shows some detail in the cloud systems on this Saturnian moon. The southern hemisphere appears lighter in contrast, a well-defined band is seen near the equator, and a dark collar is evident at the north pole. All these bands are associated with cloud circulation in Titan's atmosphere. The extended haze, composed of submicron-size particles, is seen clearly around the satellite's limb. This image was composed from blue, green and violet frames. For a high resolution image, click here. |
|
Iapetus' New Year's Flyby
| Description |
Iapetus' New Year's Flyby |
| Full Description |
This map of the surface of Saturn's moon Iapetus (1,436 kilometers, or 892 miles across), generated from images taken by NASA's Voyager spacecraft, illustrates the imaging coverage planned during Cassini's flyby on Dec. 31, 2004. Cassini will glide past Iapetus at a distance of approximately 123,400 kilometers (76,700 miles) on New Year's Eve, at a speed of about 2 kilometers per second (4,474 miles per hour). Imaging coverage will be focused primarily on the dark terrain of Iapetus' leading hemisphere, in the area known as Cassini Regio. The spacecraft's namesake, Jean-Dominique Cassini, discovered Iapetus in 1672 and was only able to see the moon's bright trailing hemisphere. Colored lines on the map enclose regions that will be covered at different imaging scales as Cassini approaches Iapetus. Images from Cassini's flyby will be superior in resolution to those obtained by Voyager 2 in August 1981. Voyager 2 passed Iapetus at a distance of approximately 909,000 kilometers (564,800 miles) at closest approach, yielding a best resolution image of about 8 kilometers per pixel. The resolution of Cassini images from this flyby will be 1.5 kilometers per pixel and better. 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 |
| Date |
December 30, 2004 |
|
Enceladus: Trailing Hemisphe
…
| Description |
Enceladus: Trailing Hemisphere |
| Full Description |
A variety of surface ages is revealed in this 16-image mosaic taken during Cassini's first close flyby of Enceladus, on Feb. 17, 2005. This mosaic shows the trailing hemisphere of Enceladus -- the side of Enceladus that always faces away from the direction of the satellite's orbital motion. This hemisphere is dominated by Sarandib Planitia (just right of center), a region thought to be dominated by smooth plains in NASA Voyager 2 images taken in August 1981, but shown here in much higher resolution images to be covered in low ridges and troughs. Other major features seen in the region include Labtayt Sulci, a 1-kilometer- (0.6-mile-) deep canyon running northward from a cusp in the south polar terrain boundary (Cashmere Sulci) at lower right to a set of 1-kilometer-tall ridges (Cufa Dorsa and Ebony Dorsum) east of Sarandib Planitia (also seen in Enceladus Mosaic), as well as Samarkand Sulci, a band of ridges and troughs running along the western margin of Sarandib Planitia almost all the way north to Enceladus' north pole. In contrast to the youthful terrain of Sarandib Planitia and the terrain south of it, the terrain north and west of Sarandib appears much older. These regions are covered with impact craters at various stages of degradation, either from viscous relaxation (which causes the craters to flatten over time), or from tectonic activity. To create this single full-disk mosaic, the 16 images were reprojected into an orthographic projection centered at 2.3 degrees north latitude, 317.7 degrees west longitude with a pixel scale of 63 meters (207 feet) per pixel. The original images were taken by the Cassini spacecraft narrow-angle and wide-angle cameras from distances ranging from 10,850 to 29,750 kilometers (6,740 to 18,490 miles). The images had a phase, or sun-Enceladus-spacecraft, angle of 28 degrees. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter 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 |
December 29, 2006 |
|
The Other Side of Iapetus
| Description |
Cassini captures the first high-resolution glimpse of the bright trailing hemisphere of Saturn's moon Iapetus. |
| Full Description |
Cassini captures the first high-resolution glimpse of the bright trailing hemisphere of Saturn's moon Iapetus. This false-color mosaic shows the entire hemisphere of Iapetus (1,468 kilometers, or 912 miles across) visible from Cassini on the outbound leg of its encounter with the two-toned moon in Sept. 2007. The central longitude of the trailing hemisphere is 24 degrees to the left of the mosaic's center. Also shown here is the complicated transition region between the dark leading and bright trailing hemispheres. This region, visible along the right side of the image, was observed in many of the images acquired by Cassini near closest approach during the encounter. Revealed here for the first time in detail are the geologic structures that mark the trailing hemisphere. The region appears heavily cratered, particularly in the north and south polar regions. Near the top of the mosaic, numerous impact features visible in NASA Voyager 2 spacecraft images (acquired in 1981) are visible, including the craters Ogier and Charlemagne. The most prominent topographic feature in this view, in the bottom half of the mosaic, is a 450-kilometer (280-mile) wide impact basin, one of at least nine such large basins on Iapetus. In fact, the basin overlaps an older, similar-sized impact basin to its southeast. In many places, the dark material -- thought to be composed of nitrogen-bearing organic compounds called cyanides, hydrated minerals and other carbonaceous minerals -- appears to coat equator-facing slopes and crater floors. The distribution of this material and variations in the color of the bright material across the trailing hemisphere will be crucial clues to understanding the origin of Iapetus' peculiar bright-dark dual personality. The view was acquired with the Cassini spacecraft narrow-angle camera on Sept. 10, 2007, at a distance of about 73,000 kilometers (45,000 miles) from Iapetus. The color seen in this view represents an expansion of the wavelengths of the electromagnetic spectrum visible to human eyes. The intense reddish-brown hue of the dark material is far less pronounced in true color images. The use of enhanced color makes the reddish character of the dark material more visible than it would be to the naked eye. This mosaic consists of 60 images covering 15 footprints across the surface of Iapetus. The view is an orthographic projection centered on 10.8 degrees south latitude, 246.5 degrees west longitude and has a resolution of 426 meters (0.26 miles) per pixel. An orthographic view is most like the view seen by a distant observer looking through a telescope. At each footprint, a full resolution clear filter image was combined with half-resolution images taken with infrared, green and ultraviolet spectral filters (centered at 752, 568 and 338 nanometers, respectively) to create this full-resolution false color mosaic. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the, Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 8, 2007 |
|
| Description |
Shepherd Satellites |
| Full Description |
This image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster than the outer one, the satellites lap each other every 25 days. This picture was taken on August 15, 1981, when Voyager 2 was 10.5 million kilometers (6.6 million miles) from Saturn. At that instant, the shepherds were less than 1,800 kilometers (1,100 miles) apart. For higher resolution, click here. |
|
| Description |
Ring Spokes |
| Full Description |
Voyager 2 obtained this high-resolution picture of Saturn's rings on August 22, 1981 when the spacecraft was 4 million km (2.5 million mi) away. Evident here are the numerous "spoke" features in the B ring, their sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Spokes of this nature were observed to persist at times for two or three rotations of the ring about the planet. Freshly-formed spokes seemed to revolve around the planet at the same rate as the rotation of the magnetic field and the interior of Saturn, independent of their distance from the center of Saturn. It is therefore suspected that the tiny dust grains which form the spokes are electrically charged. Older spokes, which presumably have lost their electrical charge, revolve with the underlying larger ring particles. For a high resolution image, click here. |
|
| 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 enhanced-color image was created by combining three images taken through ultraviolet, violet and green filters on July 12, 1981. Several changes were apparent in Saturn's atmosphere since Voyager 1's November 1980 encounter, and the planet's rings had brightened considerably due to the higher sun angle. Voyager 2 was 43 million kilometers (27 million miles) from Saturn when it took this photograph. (P-23880) |
|
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Saturn appears serene and majestic in the first color composite made of images taken by NASA's Cassini spacecraft on its approach to the ringed planet, with arrival still 20 months away. The planet was 285 million kilometers (177 million miles) away from the spacecraft, nearly twice the distance between the Sun and Earth, when Cassini took images of it in various filters as an engineering test on Oct. 21, 2002. It is summer in Saturn's southern hemisphere. The Sun is a lofty 27 degrees below the equator and casts a semi-circular shadow of the planet on the rings. The shadow extends partway across the rings, leaving the outer A ring in sunlight. The last Saturn-bound spacecraft, Voyager 2, arrived in early northern spring. Many features seen in Voyager images -- spoke-like markings on the rings, clouds and eddies in the hazy atmosphere, ring-shepherding moons -- are not yet visible to Cassini. Titan, Saturn's largest moon, appears in the upper left. It is the only moon resolved from this distance. This composite uses a threefold enhancement in the brightness of Titan relative to the brightness of Saturn. Titan is a major attraction for scientists of the Cassini-Huygens mission. They will study its haze-enshrouded atmosphere and peer down, with special instrumentation, to its surface to look for evidence of organic processes similar to those that might have occurred on the early Earth, prior to the emergence of life. Cassini will enter orbit around Saturn on July 1, 2004. It will release a piggybacked probe, Huygens, which will descend through Titan's atmosphere on Jan. 14, 2005. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Information about the mission is available online at http://saturn.jpl.nasa.gov . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C. *Image Note: * * Credit: NASA/JPL/Southwest Research Institute For higher resolution, click here. |
|
Saturn Storms Observed by Vo
…
| 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 |
Voyager 1 and 2 observed radio signals from lightning which were interpreted as being from a persistent, low-latitude storm system which was extended in longitude, perhaps similar to the region highlighted on this Voyager 2 image acquired on Aug. 4, 1981, from a distance of 21 million kilometers (13 million miles). Similar lightning detections by Cassini suggest a much more variable pattern of storms which come and go on time scales of days. The differences may be explained, in part, by stark differences in the shadows cast by the rings between the Voyager and Cassini eras. This image was previously released on December 5, 1998. For original caption see PIA01364. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radio and plasma wave science team is based at the University of Iowa, Iowa City. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the instrument team's home page, http://www-pw.physics.uiowa.edu/plasma-wave/cassini/home.html . Image Credit: NASA/JPL |
|
| Description |
Ring Spokes |
| Full Description |
Voyager 2 obtained this high-resolution picture of Saturn's rings on August 22, 1981 when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous "spoke" features in the B ring, their sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Spokes of this nature were observed to persist at times for two or three rotations of the ring about the planet. Freshly-formed spokes seemed to revolve around the planet at the same rate as the rotation of the magnetic field and the interior of Saturn, independent of their distance from the center of Saturn. It is therefore suspected that the tiny dust grains which form the spokes are electrically charged. Older spokes, which presumably have lost their electrical charge, revolve with the underlying larger ring particles. For a high resolution image, click here. |
|
| Description |
Ring Color Variations |
| Full Description |
Possible variations in chemical composition from one part of Saturn's ring system to another are visible in this Voyager 2 picture as subtle color variations that can be recorded with special computer-processing techniques. This highly enhanced color view was assembled from clear, orange and ultraviolet frames obtained August 17, 1981 from a distance of 8.9 million kilometers (5.5 million miles). In addition to the previously known blue color of the C-ring and the Cassini Division, the picture shows additional color differences between the inner B-ring and outer region (where the spokes form) and between these and the A-ring. For a high resolution image, click here. |
|
Clumps in the F Ring
| 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 |
Scientists have only a rough idea of the lifetime of clumps in Saturn's rings - a mystery that Cassini may help answer. The latest images taken by the Cassini-Huygens spacecraft show clumps seemingly embedded within Saturn¿s narrow, outermost F ring. The narrow angle camera took the images on Feb. 23, 2004, from a distance of 62.9 million kilometers (39 million miles). The two images taken nearly two hours apart show these clumps as they revolve about the planet. The small dot at center right in the second image is one of Saturn's small moons, Janus, which is 181 kilometers, (112 miles) across. Like all particles in Saturn's ring system, these clump features orbit the planet in the same direction in which the planet rotates. This direction is clockwise as seen from Cassini's southern vantage point below the ring plane. Two clumps in particular, one of them extended, is visible in the upper part of the F ring in the image on the left, and in the lower part of the ring in the image on the right. Other knot-like irregularities in the ring's brightness are visible in the image on the right. The core of the F ring is about 50 kilometers (31miles) wide, and from Cassini's current distance, is not fully visible. The imaging team enhanced the contrast of the images and magnified them to aid visibility of the F ring and the clump features. The camera took the images with the green filter, which is centered at 568 nanometers. The image scale is 377 kilometers (234 miles) per pixel. NASA¿s two Voyager spacecraft that flew past Saturn in 1980 and 1981 were the first to see these clumps. The Voyager data suggest that the clumps change very little and can be tracked as they orbit for 30 days or more. No clump survived from the time of the first Voyager flyby to the Voyager 2 flyby nine months later. Scientists are not certain of the cause of these features. Among the theories proposed are meteoroid bombardments and inter-particle collisions in the F ring. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Space Science Institute |
|
| Description |
Shepherd Satellites |
| Full Description |
This image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster than the outer one, the satellites lap each other every 25 days. This picture was taken on August 15, 1981, when Voyager 2 was 10.5 million kilometers (6.6 million miles) from Saturn. At that instant, the shepherds were less than 1,800 kilometers (1,100 miles) apart. For higher resolution, click here. |
|
| Description |
Shepherd Satellites |
| Full Description |
This image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster than the outer one, the satellites lap each other every 25 days. This picture was taken on August 15, 1981, when Voyager 2 was 10.5 million kilometers (6.6 million miles) from Saturn. At that instant, the shepherds were less than 1,800 kilometers (1,100 miles) apart. For higher resolution, click here. |
|
| 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) |
|
Saturn's A Ring From the Ins
…
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The best view of Saturn's rings in the ultraviolet indicates there is more ice toward the outer part of the rings, than in the inner part, hinting at the origins of the rings and their evolution. Images taken during the Cassini spacecraft's orbital insertion on June 30 show compositional variation in the A, B and C rings. From the inside out, the "Cassini Division" in faint red at left is followed by the A ring in its entirety. The Cassini Division at left contains thinner, dirtier rings than the turquoise A ring, indicating a more icy composition. The red band roughly three-fourths of the way outward in the A ring is known as the Encke gap. The ring system begins from the inside out with the D, C, B and A rings followed by the F, G and E rings. The red in the image indicates sparser ringlets likely made of "dirty," and possibly smaller, particles than in the icier turquoise ringlets. This image was taken with the Ultraviolet Imaging Spectrograph instrument, which is capable of resolving the rings to show features up to 97 kilometers (60 miles) across, roughly 100 times the resolution of ultraviolet data obtained by the Voyager 2 spacecraft. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Ultraviolet Imaging Spectrograph was built at, and the team is based at the University of Colorado, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Ultraviolet Imaging Spectrograph team home page, http://lasp.colorado.edu/cassini . Image Credit: NASA/JPL/University of Colorado |
|
Video greeting to NASA JPL b
…
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Saturn. Why this change? Well, for one thing it made a more straightforward storyline. And more important, the special effects department couldn't produce a Saturn that Stanley found convincing. That was just as well because if they had done so, the movie would have been badly dated by the Voyager missions, which showed Saturn's rings to be far more implausible than anyone had ever imagined. I have seen enough instances where Nature imitates art, so I'm going to keep my fingers crossed on what Cassini discovers at Iapetus. I want to thank everyone associated with this mission and the overall project. It may lack the glamour of manned spaceflight, but science projects are tremendously important for our understanding of the Solar System. And who knows, one day our survival on Earth might depend on what we discover out there. This is Arthur Clarke, wishing you a successful flyby., Video greeting to NASA JPL to mark the Iapetus flyby of Cassini spacecraft -- Sept. 10, 2007 by Arthur C. Clarke (The following is a transcript of the video greeting.) Hello! This is Arthur Clarke, joining you from my home in Colombo, Sri Lanka. I'm delighted to be part of this event to mark Cassini's flyby of Iapetus. I send my greetings to all my friends - known and unknown - who are gathered for this important occasion. I only wish I could be with you, but I'm now completely wheelchaired by Polio and have no plans to leave Sri Lanka again. Thanks to the World Wide Web, I have been following the progress of Cassini-Huygens mission from the time it was launched several years ago. As you know, I have more than a passing interest in Saturn. And I was really spooked in early 2005, when the Huygens probe returned sound recordings from the surface of Titan. This is exactly what I had described in my 1975 novel Imperial Earth, where my character is listening to the winds blowing over the desert plains. Perhaps that was a foretaste of things to come! On September 10, if everything goes according to plan, Cassini would give us our closest look at Iapetus - one of Saturn's most interesting moons. Half of Iapetus appears as dark as asphalt, and the other half is as bright as snow. When Giovanni Cassini discovered Iapetus in 1671, he could only see the bright side. We had a better glimpse when Voyager 2 flew past in August 1981 - but that was from almost a million kilometers away. In contrast, Cassini is going to come within a little over one thousand kilometers of Iapetus. This is a particularly exciting moment for fans of 2001: A Space Odyssey - because that's where the lone astronaut Dave Bowman discovers the Saturn monolith, which turns out to be a gateway to the stars. Chapter 35 in the novel is titled 'The Eye of Iapetus', and it contains this passage: "Iapetus was approaching so slowly that it scarcely seemed to move, and it was impossible to tell the exact moment when it made the subtle change from an astronomical body to a landscape, only fifty miles below. The faithful verniers gave their last spurts of thrust, then closed down forever. The ship was in its final orbit, completing a revolution every three hours at a mere eight hundred miles an hour - all the speed that was necessary in this feeble gravitation field." More than 40 years later, I cannot remember why I placed the Saturn monolith on Iapetus. At that time, in the early days of the Space Age, earth-based telescopes couldn't show any details of this celestial body. But I have always had a strange fascination for Saturn and its family of Moons. By the way, that 'family' has been growing at a very impressive rate. When Cassini was launched, we knew of only 18 moons. I understand it is now 60 - and counting.I can't resist the temptation to say: My God, it's full of moons! But in the movie, Stanley Kubrick decided to place all the actions at Jupiter, not |
|
| Description |
Shepherd Satellites |
| Full Description |
This image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster than the outer one, the satellites lap each other every 25 days. This picture was taken on August 15, 1981, when Voyager 2 was 10.5 million kilometers (6.6 million miles) from Saturn. At that instant, the shepherds were less than 1,800 kilometers (1,100 miles) apart. For higher resolution, click here. |
|
| 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 image taken by the Voyager 2 spacecraft of Saturn's A-ring shows the thin F-ring bracketed by its two shepherding satellites. Because the inner moon revolves around the planet slightly faster than the outer one, the satellites lap each other every 25 days. This picture was taken August 15, 1981, when Voyager 2 was 10.5 million kilometers (6.6 million miles) from Saturn. At that instant, the shepherds were less than 1,800 km. (1,100 mi.) apart, they passed each other about two hours later. (P-23911) |
|
Phoebe Looms in View
| 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 |
Phoebe, Saturn's largest outer moon, is the first target of exploration for the Saturn-bound Cassini spacecraft. This composite shows a set of four images taken from June 7 through June 10, 2004, by the spacecraft as it approached Phoebe. This eccentric moon has a diameter of 220 kilometers (about 136.7 miles) and orbits Saturn in the opposite direction of its larger interior moons. Previous ground-based observations have shown water ice present on its surface. In 1981, Voyager 2 captured images of Phoebe from about 2.2 million kilometers (about 1.4 million miles) away. Cassini will obtain images from a mere 2,000 kilometers (about 1,240 miles) above the moon's surface. The closest approach to Phoebe will be at 1:56 p.m. Pacific Time on June 11, just 19 days before Saturn arrival. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL |
|
Phoebe Looms in View
| 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 |
Phoebe, Saturn's largest outer moon, is the first target of exploration for the Saturn-bound Cassini spacecraft. This composite shows a set of four images taken from June 7 through June 10, 2004, by the spacecraft as it approached Phoebe. This eccentric moon has a diameter of 220 kilometers (about 136.7 miles) and orbits Saturn in the opposite direction of its larger interior moons. Previous ground-based observations have shown water ice present on its surface. In 1981, Voyager 2 captured images of Phoebe from about 2.2 million kilometers (about 1.4 million miles) away. Cassini will obtain images from a mere 2,000 kilometers (about 1,240 miles) above the moon's surface. The closest approach to Phoebe will be at 1:56 p.m. Pacific Time on June 11, just 19 days before Saturn arrival. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL |
|
| Description |
Hyperion |
| Full Description |
Voyager 2 obtained this closeup view of Saturn's satellite Hyperion on August 24, 1981, from a distance of about 500,000 kilometers (300,000 miles). This photograph was compiled from three separate images taken through violet, clear and green filters. It shows Hyperion to be an irregular, disc-shaped body. Its longest dimension is 360 km. (225 mi.), but in this view, it presents a face measuring 325 km. by 250 km. (200 mi. by 150 mi.). The irregular shape is probably a result of repeated impacts that have taken off large pieces of the satellite. The large indentation at the bottom limb is one such crater, it is about 100 km. (60 mi.) across. The numerous small pits are impact craters, the smallest measuring about 10-20 km. (6-12 mi.) across. (P-23936) |
|
| 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 true color picture was assembled from Voyager 2 Saturn images obtained August 4, 1981 from a distance of 21 million kilometers (13 million miles) on the spacecraft's approach trajectory. Three of Saturn's icy moons are evident at left. They are, in order of distance from the planet: Tethys, 1,050 km. (652 mi.) in diameter, Dione, 1,120 km. (696 mi.), and Rhea, 1,530 km. (951 mi.). The shadow of Tethys appears on Saturn's southern hemisphere. A fourth satellite, Mimas, is less evident, appearing as a bright spot a quarter-inch in in from the planet's limb about half an inch above Tethys, the shadow of Mimas appears on the planet about three-quarters of an inch directly above that of Tethys. The pastel and yellow hues on the planet reveal many contrasting bright and darker bands in both hemispheres of Saturn's weather system. For a high resolution image, click here. |
|
Saturn's C and B Rings From
…
| 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 |
Images taken during the Cassini spacecraft's orbital insertion on June 30 show definite compositional variation within the rings. This image shows, from left to right, the outer portion of the C ring and inner portion of the B ring. The B ring begins a little more than halfway across the image. The general pattern is from "dirty" particles indicated by red to cleaner ice particles shown in turquoise in the outer parts of the rings. The ring system begins from the inside out with the D, C, B and A rings followed by the F, G and E rings. This image was taken with the Ultraviolet Imaging Spectrograph instrument, which is capable of resolving the rings to show features up to 97 kilometers (60 miles) across, roughly 100 times the resolution of ultraviolet data obtained by the Voyager 2 spacecraft. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Ultraviolet Imaging Spectrograph was built at, and the team is based at the University of Colorado, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Ultraviolet Imaging Spectrograph team home page, http://lasp.colorado.edu/cassini . Image Credit: NASA/JPL/University of Colorado |
|
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 |
|
Saturn's C-Ring
| title |
Saturn's C-Ring |
| date |
08.03.1981 |
| description |
This Voyager 2 view, focusing on Saturn's C-ring (and to a lesser extent, the B-ring at top and left) was compiled from three separate images taken through ultraviolet, clear and green filters. When it acquired these frames, Voyager 2 was 2.7 million kilometers (1.7 million miles) from the planet. In general, C-ring material is very bland and gray, the color of dirty ice. Color differences between this ring and the B-ring indicate differing surface compositions for the material composing these complex structures. More than 60 bright and dark ringlets are evident here, the small, bland squares are caused by the removal of reseau (reference) marks during processing. *Image Credit*: NASA |
|
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 |
|
Jupiter's Rings
| title |
Jupiter's Rings |
| date |
02.24.2007 |
| description |
The New Horizons Long Range Reconnaissance Imager (LORRI) snapped this photo of Jupiter's ring system on February 24, 2007, from a distance of 7.1 million kilometers (4.4 million miles). This processed image shows a narrow ring, about 1,000 kilometers (600 miles) wide, with a fainter sheet of material inside it. The faint glow extending in from the ring is likely caused by fine dust that diffuses in toward Jupiter. This is the outer tip of the "halo," a cloud of dust that extends down to Jupiter's cloud tops. The dust will glow much brighter in pictures taken after New Horizons passes to the far side of Jupiter and looks back at the rings, which will then be sunlit from behind. Jupiter's ring system was discovered in 1979, when astronomers spied it in a single image taken by the Voyager 1 spacecraft. Months later, Voyager 2 carried out more extensive imaging of the system. It has since been examined by NASA's Galileo and Cassini spacecraft, as well as by the Hubble Space Telescope and large ground-based observatories. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
|
The Other Side of Iapetus
| title |
The Other Side of Iapetus |
| date |
09.10.2007 |
| description |
Cassini captures the first high-resolution glimpse of the bright trailing hemisphere of Saturn's moon Iapetus. This false-color mosaic shows the entire hemisphere of Iapetus (1,468 kilometers, or 912 miles across) visible from Cassini on the outbound leg of its encounter with the two-toned moon in Sept. 2007. The central longitude of the trailing hemisphere is 24 degrees to the left of the mosaic's center. Also shown here is the complicated transition region between the dark leading and bright trailing hemispheres. This region, visible along the right side of the image, was observed in many of the images acquired by Cassini near closest approach during the encounter. Revealed here for the first time in detail are the geologic structures that mark the trailing hemisphere. The region appears heavily cratered, particularly in the north and south polar regions. Near the top of the mosaic, numerous impact features visible in NASA Voyager 2 spacecraft images (acquired in 1981) are visible, including the craters Ogier and Charlemagne. The most prominent topographic feature in this view, in the bottom half of the mosaic, is a 450-kilometer (280-mile) wide impact basin, one of at least nine such large basins on Iapetus. In fact, the basin overlaps an older, similar-sized impact basin to its southeast. In many places, the dark material -- thought to be composed of nitrogen-bearing organic compounds called cyanides, hydrated minerals and other carbonaceous minerals -- appears to coat equator-facing slopes and crater floors. The distribution of this material and variations in the color of the bright material across the trailing hemisphere will be crucial clues to understanding the origin of Iapetus' peculiar bright-dark dual personality. The view was acquired with the Cassini spacecraft narrow-angle camera on Sept. 10, 2007, at a distance of about 73,000 kilometers (45,000 miles) from Iapetus. The color seen in this view represents an expansion of the wavelengths of the electromagnetic spectrum visible to human eyes. The intense reddish-brown hue of the dark material is far less pronounced in true color images. The use of enhanced color makes the reddish character of the dark material more visible than it would be to the naked eye. This mosaic consists of 60 images covering 15 footprints across the surface of Iapetus. The view is an orthographic projection centered on 10.8 degrees south latitude, 246.5 degrees west longitude and has a resolution of 426 meters (0.26 miles) per pixel. An orthographic view is most like the view seen by a distant observer looking through a telescope. At each footprint, a full resolution clear filter image was combined with half-resolution images taken with infrared, green and ultraviolet spectral filters (centered at 752, 568 and 338 nanometers, respectively) to create this full-resolution false color mosaic. 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 |
|
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 |
|
Triton - Detail of Dark and
…
| 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 |
|
Ariel - Highest Resolution C
…
| title |
Ariel - Highest Resolution Color Picture |
| date |
01.29.1996 |
| description |
The complex terrain of Ariel is viewed in this image, the best Voyager 2 color picture of the Uranian moon. The individual photos used to construct this composite were taken Jan. 24, 1986, from a distance of 170,000 kilometers (105,000 miles). Voyager captured this view of Ariel's southern hemisphere through the green, blue and violet filters of the narrow-angle camera, the resolution is about 3 km (2 mi). Most of the visible surface consists of relatively intensely cratered terrain transected by fault scarps and fault-bounded valleys (graben). Some of the largest valleys, which can be seen near the terminator (at right), are partly filled with younger deposits that are less heavily cratered. Bright spots near the limb and toward the left are chiefly the rims of small craters. Most of the brightly rimmed craters are too small to be resolved here, although one about 30 km (20 mi) in diameter can be easily distinguished near the center. These bright-rim craters, though the youngest features on Ariel, probably have formed over a long span of geological time. Although Ariel has a diameter of only about 1,200 km (750 mi), it has clearly experienced a great deal of geological activity in the past. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. *Image Credit*: JPL |
|
Voyager 2 Looks at Saturn's
…
| title |
Voyager 2 Looks at Saturn's Rings |
| date |
08.17.1981 |
| description |
Voyager 2 false-color image of Saturn's rings. Subtle color variations due to differences in surface composition of the particles making up the rings are enhanced in this image produced by combining ultraviolet, clear, and orange frames. The frame was taken from a distance of 8.9 million km on August 17, 9 days before closest approach, and measures about 68,000 km from top to bottom. (Voyager 2, P-23953) *Image Credit*: NASA |
|
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 |
|
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 |
|
Miranda's Geologic History
| title |
Miranda's Geologic History |
| date |
01.24.1996 |
| description |
Miranda reveals a complex geologic history in this view, acquired by Voyager 2 on Jan. 24, 1986, around its close approach to the Uranian moon. At least three terrain types of different age and geologic style are evident at this resolution of about 700 meters (2,300 feet). Visible in this clear-filter, narrow-angle image are, from left: (1) an apparently ancient, cratered terrain consisting of rolling, subdued hills and degraded medium-sized craters (2) a grooved terrain with linear valleys and ridges developed at the expense of, or replacing, the first terrain type: and (3) a complex terrain seen along the terminator, in which intersecting curvilinear ridges and troughs are abruptly truncated by the linear, grooved terrain. Voyager scientists believe this third terrain type is intermediate in age between the first two. The Voyager project is managed for NASA by the Jet Propulsion Laboratory. *Image Credit*: JPL |
|
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 |
|
Voyager 2 Launch
| title |
Voyager 2 Launch |
| date |
08.20.1977 |
| description |
Voyager 2 was launched on August 20, 1977, from the NASA Kennedy Space Center at Cape Canaveral in Florida, propelled into space on a Titan/Centaur rocket. JPL manages and controls the Voyager project for NASA's Office of Space Science. *Image Credit*: NASA |
|
Saturn taken from Voyager 2
| title |
Saturn taken from Voyager 2 |
| date |
08.04.1998 |
| description |
This true color picture was assembled from Voyager 2 Saturn images obtained Aug. 4 from a distance of 21 million kilometers (13 million miles) on the spacecraft's approach trajectory. Three of Saturn's icy moons are evident at left. They are, in order of distance from the planet: Tethys, 1,050 km. (652 mi.) in diameter, Dione, 1,120 km. (696 mi.), and Rhea, 1,530 km. (951 mi.). The shadow of Tethys appears on Saturn's southern hemisphere. A fourth satellite, Mimas, is less evident, appearing as a bright spot a quarter-inch in from the planet's limb about half an inch above Tethys, the shadow of Mimas appears on the planet about three-quarters of an inch directly above that of Tethys. The pastel and yellow hues on the planet reveal many contrasting bright and darker bands in both hemispheres of Saturn's weather system. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif. *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 |
|
|
