Browse All : Neptune and Voyager 2

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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
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.
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)
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
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
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
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
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
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
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
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
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
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
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
Montage of Neptune and Trito …
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
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
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 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
A89-7005
Photographer : JPL August 17 …
8/17/89
Description Photographer : JPL August 17 to 19, 1989 Range : 11.5 million km (7.1 million mi.) to 7.9 million km (4.9 million mi.) Four black and white images of Neptune's largest satellite, Triton, show it's rotation between the first (upper left) image and the last (lower right). Resolution improves from about 200 km (124 miles) to 150 km (93 miles) per line pair. Triton's south pole lies in the dark area near the bottom of the disk. Dark spots, roughly 1,000 km (620 miles) across, occur near the equator, and show Triton rotation between images. The rotation appears to be synchronous with Triton's 5.88-day orbital period (i.e., Triton rotates on its axis in the same time it revolves around Neptune.) The spots' constant rotation rate and their visibility near the edge of the disk suggest the spots are surface features. Whatever atmosphere is present on Triton appears transparent enough that Voyager 2's cameras can see through it.
Date 8/17/89
A89-7006
Photographer : JPL Range : 1 …
8/21/89
Description Photographer : JPL Range : 12 million km (7.5 million miles) Resolution 110 km (68 miles) per pixel. These 2 images of Neptune were taken by Voyager 2's narrow-angle camera. During the 17.6 hours between the left and right images, the Great Dark Spot, at 22 degrees south latitude (left of center), has completed a little less than one rotation of Neptune. The smaller dark spot, at 54 south, completed a little more than one rotation, as can be seen by comparing its relative positions in the two pictures. The Great Dark Spot and the smaller spot have a relative velocity of 100 meters per second (220 miles an hour). The light and dark bands circling Neptune indicate predominantly zonal (east-west) motion. The diffuse white feature north of the Great Dark Spot is near Neptune's equator, and rotates with about the same period as the Great Dark Spot. Streak of bright clouds at the south edge, and just east of the Great Dark Spot, are its constatnt companions, and change the details of their appearance, often within a few hours. Changing brightness of the cloud streaks could be a result of vertical mortions.
Date 8/21/89
A89-7007
Photographer : JPL The brigh …
8/21/89
Description Photographer : JPL The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipation over periods of several to tens of hours. In this sequence spanning two rotations of Neptune (about 36 hours) Voyager 2 observed cloud evolution in the region around the Great Dark Spot (GDS) at an effective resolution of about 100 km (62 miles) per pixel. The surprisingly rapid changes which occur over the 18 hours separating each panel shows that in this region Neptune's weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards--the Earth and the GDS are of similar size -- and in Neptune's frigid atmosphere, where temperatures are as low as 55 degree Kelvin (-360F), the cirrus clouds are composed of frozen methane rather than Earth's crystalse of water ice.
Date 8/21/89
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
A89-7023
Photographer : JPL P-34675 R …
8/21/89
Description Photographer : JPL P-34675 Range : 5.9 million km. ( 3.6 million miles ) Orbital Speed : 40,000 km/hr. or 25,000 mi/hr. The most recently discovered satellites of Neptune, 1989N5 and 1989N6, are shown in this Voyager 2 image. Their high orbital speed, in combination with the a 15 sec. exposure, has caused faint streaks. 1989N3 was discovered in early August, 1989. 1989N6 is distinguished by an orbit that is inclined 4.5 degrees to Neptune's equatorial plane, the only new satellite in the Neptune system to have noticably inclined orbit. 1989N5 cicles Neptune every 7.5 hours at a ditance of 25,000 km. or 15,500 miles above the cloud tops. 1989N6 orbits Neptune 23,00 km. or 14,000 miles from cloud tops every 7.1 hours
Date 8/21/89
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
A89-7033
Photographer : JPL Range : 4 …
8/24/89
Description Photographer : JPL Range : 4.7 million km (2.9 million mi.) Nereid, the last satellite of Neptune to be discovered before Voyager's recent discoveries, was first seen by Gerard Kuiper in 1949. Until this Voyager 2 image was obtained, all that was known about Nereid was its orbital parameters and intrinsic brightness. With a resolution of 43 kilometers (26.6 mi.) per pixel, this image has sufficient detail to show the overall size and albedo. Nereid is about 170 km (105 mi.) across and reflects about 12 percent of the incident light.
Date 8/24/89
A89-7040
Photographer: JPL P-34630 Ra …
8/26/89
Description Photographer: JPL P-34630 Range: 10.5 million kilometers (6.5 million miles) This cylindrical projection view of Neptune uses five narrow-angle images equally spaced around the planet. They were taken by Voyager 2 over the course of a Neptunian day, an interval of about 18 hours. Latitude lines are horizontal in the image, and range from 80 degrees south to 30 degrees north of the equator. Near the center, the Great Dark Spot leaves a disturbed wave-like pattern that stretches around Neptune. Features further south move eastward at speeds up to 400 mph relative to the Great Dark Spot. The features are storms--moving cloud systems that persist for months or longer. The weather forecast for Neptune is therefore continued high winds and cold with little change in temperature.
Date 8/26/89
A89-7042
Photographer: JPL P-34578 BW …
8/11/89
Description Photographer: JPL P-34578 BW One of two new ring arcs, or partial rings, discovered by Voyager 2, is faintly visible just outside the orbit of the Neptunian moon 1989N4.The 155-second exposure taken by the spacecraft's narrow-angle camera shows the glare of an overexposed Neptune to the right of the moon and ring arc. The two bright streaks below the moon and ring arc are stars. The ring arc is approximately 50,000 kilometers (30,000 miles) long. The second ring arc, not apparent here, is about 10,000 kilometers (6,000 miles) long and is assoiciated with moon 1989N3. The ring arc, along with 1989N4, orbits about 62,000 kilometers (38,000 miles) from the planet's cloud tops. Astronomers long suspected the existence of such an irregular ring system around Neptune. Data from repeated ground-based observations hinted at the existence of irregular strands of partial rings orbiting Neptune. Voyager's photographs of the ring arcs are the first photographic evidence that such a ring system exists. Voyager scientists said the ring arcs may be comprised of debris associated with the nearby moons, or may be the remnants of moons that have been torn apart or ground down through collisions. Close-up studies of the ring arcs by Voyager 2 will help determine their composition.
Date 8/11/89
A89-7045
Photographer : JPL Range : 2 …
8/26/89
Description Photographer : JPL Range : 280,000 km. ( 170,000 miles ) P-34726 BW Two 10 minute exposures of Neptune's rings clearly show the two main rings , as well as the inner faint ring and the faint band that extends planetward from roughly halfway between the two bright rings. Both bright rings have material throughout their entire orbit, and are therefore continuous. The inner ring and the broad band are much fainter than the two narrow main rings. These images were taken 1 hour and 27 minutes aprt, using the clear filter on Voyager 2's wide angle camera. These long exposures images were taken while the rings were backlit by the sun. This viewing geometry enhances the visibility of dust and allows optically thinner parts of the rings to be seen. The bright glare in the center is due to overexposure 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 the removal of blemishes during computer processing of the images. Numerous bright stars are evident in the background.
Date 8/26/89
A89-7047
Photographer : JPL Range : 6 …
8/25/89
Description Photographer : JPL Range : 660,000 km. ( 412,000 miles ) P-34711 This Voyager 2 wide angle photograph shows the shadow of Neptune on the rings. Because Neptune's shadow casts a curved profile on the rings which does not quite reach out to the outermost ring at about 38,000 km. (24,000 miles) from the cloudtops. In this photo, taken through the clear filter at a phase angle of about 135 degrees, the shadow does fall on the inner bright ring ( at about 28,000 km. (18,000 miles) from the cloudtops. The shadow also clearly delineates the radial extent of the broad sheet of material discovered extending from about halfway between the bright rings down to, and perhaps beyond the inner bright ring. A very thin, brighter of the edge of this diffuse sheet can also be seen. additional information from other images indicates that this faint material extends further in, to at least the position of the innermost faint ring discovered at about 17,000 km (11,000 mi.) from the cloudtops.
Date 8/25/89
A89-7050
Photographer: JPL P-34715 Ra …
8/27/89
Description Photographer: JPL P-34715 Range: 900,000 kilometers (560,000 miles) This post-encounter view of the south pole of Neptune was obtained after Voyager 2 passed the planet and sped away on a southward-trending trajectory. Voyager's wide-angle camera saw features as small as 120 km (75 mi) in diameter. The angle between the Sun, the center of the planet, and the spacecraft is 137 _, so the entire south polar region is illuminated. Near the bright limb, clouds located at 71 and 42 degrees south latitude rotate eastward onto Neptune's night side. A bright cloud (bottom center) lies within 1.5 _ of Neptune's south pole, which has been determined from the orbits of the planet's rings and satellites. The feature is believed to be created by an organized circulation around the pole that forms a clear "eye" at the center of the system.
Date 8/27/89
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
AC86-7042
Photographer : JPL Range : 1 …
1/24/86
Description Photographer : JPL Range : 1 illion km. ( 600,000 mi. ) Resolution : 140 km. ( 90 mi. ) P-29539C This Voyager 2 image of Uranus was captured as the spacecraft was leaving Uranus behind on its cruise to Neptune. The image is a color composite of three photographs taken through blue, grren, and orange filters. Thin thin crecent seen here is at an angle of 153 degrees between the the spacecraft, the planet, and the sun. Even at this extreme angle, uranus retains the pale blue-green color seen by the ground based astronomers and recorded by Voyager 2 during its historic encounter, this color results from the presence of methane in Uranus' atmosphere. The gas absorbs red wavelengths of light, leaving the predominant hue seen here. The tendency for the cresent to become white at the extreme edge is cased by the presence of a high-altitude haze. Voyager 2, having encountered Jupiter in 1979, Saturn in 1981, and Uranus in 1986, will proceed on its jouney to Neptune. Closest approach is scheduled for August 24, 1989.
Date 1/24/86
AC89-7001
Photo by Voyager 2 (JPL) Dur …
8/21/89
Description Photo by Voyager 2 (JPL) During August 16 and 17, 1989, the Voyager 2 narrow-angle camera was used to photograph Neptune almost continuously, recording approximately two and one-half rotations of the planet. These images represent the most complete set of full disk Neptune images that the spacecraft will acquire. This picture from the sequence shows two of the four cloud features which have been tracked by the Voyager cameras during the past two months. The large dark oval near the western limb (the left edge) is at a latitude of 22 degrees south and circuits Neptune every 18.3 hours. The bright clouds immediately to the south and east of this oval are seen to substantially change their appearances in periods as short as four hours. The second dark spot, at 54 degrees south latitude near the terminator (lower right edge), circuits Neptune every 16.1 hours. This image has been processed to enchance the visibility of small features, at some sacrifice of color fidelity. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. (JPL Ref: A-34611 Voyager 2-N29)
Date 8/21/89
AC89-7003
Photographer : JPL Range : 1 …
8/21/89
Description Photographer : JPL Range : 16 million km (9.9 million miles) P-34616 This series of six Voyager 2 images of Neptune through different filters reveals altitude in Neptune's clouds. The top three images, taken though orange, violet, and ultraviolet filters by the narrow-angle camera, show several bright cloud features, clearly visible in each image. The "scooter" cloud, at 42 degrees south latitude, although prominent in the orange image, is invisible in ultraviolet, where scattering by atmospheric molecules is strongest. The disappearance can be understood if the "scooter cloud has more obscurring atmosphere above it ( i.e. the scooter cloud is lower ) than other bright clouds. The observation also suggest that the centrally located Great Dark Spot is also a low lying feature because it also loses visiblity in the ultraviolet image. The lower three wide angle images ( from left to right: orange, weak methane [541nm], and strong methane [619nm] are arranged in increasing absorption by methane in Neptune's atmosphere. In the lower images the "scooter cloud" becomes less obvious from left to right, implying there is relatively more absorbing methane above the "scooter cloud". Thus the set of images also implies that the "scooter cloud" is deeper in the atmosphere ( and therefore at higher atmospheric pressure ) than the other bright clouds.
Date 8/21/89
AC89-7009
Photographer : JPL This pict …
8/21/89
Description Photographer : JPL This picture of Neptune was produced from images taken through the ultraviolet, violet and green filters of the Voyager 2 wide-angle camera. This "false" color image has been made to show clearly details of the cloud structure and to paint clouds located at different altitudes with different colors. Dark, deeplying clouds tend to be masked in the ultraviolet wavelength since overlying air molecules are particularly effective in scattering sunlight there which brightens the sky above them. Such areas appear dark blue in this photo. The Great Dark Spot (GDS) and the high southern latitudes have a deep bluish cast in this image, indication they are regions where visible light (but not ultraviolet light) may penetrate to a deeper layer of dark cloud or haze in Neptune's atmosphere. Conversely, the pinkish clouds may be positioned at high altitudes.
Date 8/21/89
AC89-7010
Voyager II Imagery - Neptune …
8/21/89
Description Voyager II Imagery - Neptune: This image of clouds in Neptune's atmosphere is the first that tests the accuracy of the weather forecast that was made eight days earlier to select targets for the Voyager narrow-angle camera. Three of the four targeted features are visible in this photograph, all three are close to their predicted locations. The Great Dark Spot with its bright white companion is slightly to the left of center. The small bright Scooter is below and to the left, and the second dark spot with its bright core is below the Scooter. Strong eastward winds -- up to 400 mph -- cause the second dark spot to overtake and pass the larger one every five days. The spacecraft was 6.1 million kilometers (3.8 million miles) from the planet at the time of camera shuttering, and the images use the orange, green and clear filters of the camera. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications. (JPL ref P-34632 Voyager 2 N-32C)
Date 8/21/89
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
AC89-7019
Photographer : JPL P-34666 T …
8/23/89
Description Photographer : JPL P-34666 This false color photograph of Neptune was reconstructed from two images taken by Voyager 2's wide angle camera, through the orange and two different methane filters. Objects that deep in the atmosphere are blue, while those at higher altitudes are white. Light at methane wavelengths is mostly absorbed in the deeper atmosphere. The bright, white feature is a high altitude cloud just south of the Great dark Spot. The hard, sharp inner boundary within the bright cloud is an artifact of computer processing on Earth. Other, smaller clouds associated with the Great Dark Spot are white or pink, and are also at high altitudes. Neptune's limb looks reddish because Voyager 2 is viewing it tangentially, and the sunlight is scattered back to space before it can be absorbed by methane. A long, narrow band of high-altitude clouds near the top of the image is located at 25 degrees north latitude, and faint hazes mark the equator and polor regions
Date 8/23/89
AC89-7022
Photographer : JPL P-34668 R …
8/23/89
Description Photographer : JPL P-34668 Range : 2.8 million km. ( 1.7 million miles ) Smallest Resolvable Feature : 50 km or 31 miles This Voyager 2 image shows the last face on view of the Great Dark Spot that Voyager 2 will take with the narrow angle camera. It was made 45 hours before the closest approach to Neptune. 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 clouds, 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 filter images.
Date 8/23/89
AC89-7036
Photographer: JPL P-34705 Th …
8/26/89
Description Photographer: JPL P-34705 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 wavelenghths are absorbed by methane gas, causing the center to appear less red. Near the edge of the planet, the haze scatters sunlight at a 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 of the full-disk photos that Voyager 2 took before beginning its endless journey into interstellar space.
Date 8/26/89
AC89-7043
Photographer : JPL Range : 1 …
8/14/89
Description Photographer : JPL Range : 14.8 million km. ( 9.2 million miles) P-34595C This contrast enhanced color photograph of Neptune was produced from images taken through the orange, green, and violet filters of the narrow angle camera. As Voyager 2 approaches Neptune, rapidly increasing image resolution is revealing striking new details in the planet's atmosphere, and this pictureshows features as small as a few hundred kilometers in extent. Bright, wispy "cirrus-type" clouds are seen overlying the Great Dark Spot (GDS) at its southern (lower) margin and over its northwest ( upper left) boundary. This is the first evidence that the GDS lies lower in the atmosphere than these bright clouds, which have remained in its vicinity for several months. Increasing detail in global banding, and the south polar can also be seen. A smaller dark spot at high southern latitudes is dimly visible near the limb at lower left.
Date 8/14/89
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
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