Galerie de photos de la planète Neptune

<h1>PIA01995: Neptune's South Polar Region</h1><div class="PIA01995" lang="en" style="width:425px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Neptune's south polar region was obtained by the NASA Voyager narrow-angle camera on Aug. 23, 1989, when it was at a distance of 25 million kilometers (1.6 million miles). The smallest cloud features are 45 kilometers (28 miles) in diameter. The image shows the discovery of shadows in Neptune's atmosphere, shadows cast onto a deep cloud bank by small elevated clouds. Located at about 68 degrees south latitude, they are the first cloud shadows ever seen by the Voyager on any planet. The dark regions adjacent to the small bright clouds are believed to be shadows, because they are on the side of the cloud that is opposite to the incoming sunlight and because they lengthen in places where the sun lies closer to the horizon. Estimates of the height of these discrete clouds above the underlying cloud bank can be obtained by careful analysis of this data. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01995" onclick="window.open(this.href); return false;" title="Voir l'image PIA01995: Neptune's South Polar Region sur le site de la NASA">Voir l'image PIA01995: Neptune's South Polar Region sur le site de la NASA.</a></div>
PIA01995: Neptune's South Polar Region
<h1>PIA01998: Neptune</h1><div class="PIA01998" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of Neptune was taken through the clear filter of the narrow-angle camera on July 16 when the Voyager 2 spacecraft was at a range of 57,000,000 kilometers (35 million miles). The image was processed by computer to show the newly resolved dark oval feature embedded in the middle of the dusky southern collar. The large dark spot nearer the equator is also prominent on the left edge of the disk. The new small dark spot rotates faster than the large dark spot indicating that the winds on Neptune have different velocities at different latitudes as is the case for Jupiter, Saturn and Uranus.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01998" onclick="window.open(this.href); return false;" title="Voir l'image PIA01998: Neptune sur le site de la NASA">Voir l'image PIA01998: Neptune sur le site de la NASA.</a></div>
PIA01998: Neptune
<h1>PIA01999: Neptune Through a Clear Filter</h1><div class="PIA01999" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">On July 23, 1989, the Voyager 2 spacecraft took this picture of Neptune through a clear filter on its narrow-angle camera. The image on the right has a latitude and longitude grid added for reference. Neptune's Great Dark Spot is visible on the left limb of the planet at about 22.5 degrees south latitude. In previous photographs, less detail was visible; now additional structure associated with the dark spot has become apparent. The jagged right edge of the large spot is real and is probably caused by cloud motion. Voyager 2 was about 47 million kilometers (29 million miles) from Neptune when this picture was taken. The smaller dark spot in the southern dark band is visible on the lower right with a small, light circle at its center. The Jet Propulsion Laboratory manages the Voyager Project for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA01999" onclick="window.open(this.href); return false;" title="Voir l'image PIA01999: Neptune Through a Clear Filter sur le site de la NASA">Voir l'image PIA01999: Neptune Through a Clear Filter sur le site de la NASA.</a></div>
PIA01999: Neptune Through a Clear Filter
<h1>PIA02200: Neptune - Partial Rings</h1><div class="PIA02200" lang="en" style="width:373px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">One of two new ring arcs, or partial rings, discovered today by NASA's Voyager 2 spacecraft, is faintly visible here just outside the orbit of the Neptunian moon 1989N4, also discovered by Voyager 2 earlier this month. The 155 second exposure taken by Voyager'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 (or 30,000 miles) long. (The second ring arc, not apparent here, is approximately 10,000 kilometers (6,000 miles) long and is associated with the moon 1989N3.) The ring arc, along with 1989N4, orbits about 62,000 kilometers (38,000 miles) from the planet's center, or about 37,000 kilometers (23,000 miles) from the planet's cloud tops. Astronomers have 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 in coming days should help determine their composition. The Voyager mission is conducted by the Jet Propulsion Laboratory for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02200" onclick="window.open(this.href); return false;" title="Voir l'image PIA02200: Neptune - Partial Rings sur le site de la NASA">Voir l'image PIA02200: Neptune - Partial Rings sur le site de la NASA.</a></div>
PIA02200: Neptune - Partial Rings
<h1>PIA02204: Neptune's Bright Crescent</h1><div class="PIA02204" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Neptune's bright crescent taken in six filters (from bottom to top: UV, violet, blue, clear, green, orange) on 31.3 August 1989. The images were shuttered in temporal order: violet, blue, UV, clear, green, orange. These images how the bright core of D2, the south polar feature, and the symmetric structure immediately surrounding the south pole. The relatively high contrast of the features in these images indicates that they extend above most of the scattering haze and absorbing methate gas in Neptune's atmosphere. [Image processing by D.A. Alexander]<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02204" onclick="window.open(this.href); return false;" title="Voir l'image PIA02204: Neptune's Bright Crescent sur le site de la NASA">Voir l'image PIA02204: Neptune's Bright Crescent sur le site de la NASA.</a></div>
PIA02204: Neptune's Bright Crescent
<h1>PIA02205: Neptune</h1><div class="PIA02205" lang="en" style="width:400px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This image of the planet Neptune was taken by the Voyager 2spacecraft on January 23, 1989, about seven months before its scheduled August 25 encounter. The spacecraft was 310 million kilometers (192 million miles) from the planet, looking from 34 degrees south of Neptune's equator through the "clear" filter. Similar images from Earth-based telescopes had shown a featureless disk, through red filters, chosen to mark methane gas, revealed irregular-shaped features associated with high-altitude hazes. The Voyager data reveal cloud structure at lower altitudes where the circulation is apparently arranged in parallel east-west bands, as is the case on Jupiter, Saturn, and Uranus. In the original image, the bright bands are about 10 percent brighter than the dark band circling the South pole. This is about the same contrast shown by Saturn, and ten times more than Uranus. The brightening and sawtooth edge around the right side are artifacts of the data processing. The Voyager project is managed by the Jet Propulsion Laboratory for the NASA Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02205" onclick="window.open(this.href); return false;" title="Voir l'image PIA02205: Neptune sur le site de la NASA">Voir l'image PIA02205: Neptune sur le site de la NASA.</a></div>
PIA02205: Neptune
<h1>PIA02209: Neptune</h1><div class="PIA02209" lang="en" style="width:662px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">These pictures of Neptune were obtained by Voyager 2 on April 26,1989, at a distance of 176 million kilometers (109 million miles). At the center of the Neptune disc, each pixel covers a square 4 degrees by 4 degrees in latitude. (Each Voyager image contains 800 pixels, picture elements, per line and 800 lines.) Resolution here was 3256 kilometers (2020 miles) per line pair. The violet, clear and orange filters of Voyager's narrow-angle camera were used to produce the color pictures. Image processing enhances contrast of the features. The picture on the right was taken five hours after that at left, during which time the planet rotated 100 degrees. The dark spot visible in the left picture appeared in clear filter images obtained three months earlier. A much brighter, white spot, prominent in the earlier images, has now apparently faded. The white spot near the south pole in the right picture is new. It was visible only faintly in a picture taken 18 hours earlier at the same longitude. This evidence of dynamic activity was unexpected in Neptune's atmosphere because Neptune receives only one-tenth of one percent as much solar energy as does the Earth.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02209" onclick="window.open(this.href); return false;" title="Voir l'image PIA02209: Neptune sur le site de la NASA">Voir l'image PIA02209: Neptune sur le site de la NASA.</a></div>
PIA02209: Neptune
<h1>PIA02210: Neptune</h1><div class="PIA02210" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This contrast enhanced color picture of Neptune was acquired by Voyager 2 at a range of 14.8 million kilometers (9.2 million miles) on August 14, 1989. It was produced from images taken through the orange, green and violet filters of Voyager's narrow angle camera. As Voyager 2 approaches Neptune, rapidly increasing image resolution is revealing striking new details in the planet's atmosphere, and this picture shows 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 in the south polar region can also be seen; a smaller dark spot at high southern latitudes is dimly visible near the limb at lower left. The Voyager Mission is conducted by the Jet Propulsion Laboratory for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02210" onclick="window.open(this.href); return false;" title="Voir l'image PIA02210: Neptune sur le site de la NASA">Voir l'image PIA02210: Neptune sur le site de la NASA.</a></div>
PIA02210: Neptune
<h1>PIA02215: Crescents of Neptune and Triton</h1><div class="PIA02215" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>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 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.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02215" onclick="window.open(this.href); return false;" title="Voir l'image PIA02215: Crescents of Neptune and Triton sur le site de la NASA">Voir l'image PIA02215: Crescents of Neptune and Triton sur le site de la NASA.</a></div>
PIA02215: Crescents of Neptune and Triton
<h1>PIA02219: Neptune</h1><div class="PIA02219" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This photograph of Neptune shows three of the features that Voyager 2 has been photographing during recent weeks. At the north 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 velocity, so it is only occasionally that they appear close to each other, such as at the time this picture was taken. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02219" onclick="window.open(this.href); return false;" title="Voir l'image PIA02219: Neptune sur le site de la NASA">Voir l'image PIA02219: Neptune sur le site de la NASA.</a></div>
PIA02219: Neptune
<h1>PIA02220: Neptune Shadows</h1><div class="PIA02220" lang="en" style="width:425px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This image of Neptune shows the discovery of shadows in Neptune's atmosphere, shadows cast onto a deep cloud band by small elevated clouds. They are the first cloud shadows ever seen by Voyager on any planet. Estimates of the height of these discrete clouds above the underlying cloud bank can be obtained by careful analysis of this data. The Voyager Mission is conducted by JPL for NASA'S Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02220" onclick="window.open(this.href); return false;" title="Voir l'image PIA02220: Neptune Shadows sur le site de la NASA">Voir l'image PIA02220: Neptune Shadows sur le site de la NASA.</a></div>
PIA02220: Neptune Shadows
<h1>PIA02222: Neptune Clouds on the Dark Spot</h1><div class="PIA02222" lang="en" style="width:400px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This photo was taken by Voyager 2's wide-angle camera. 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. Other, smaller clouds associated with the Great Dark Spot are white, and are also at high altitudes. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02222" onclick="window.open(this.href); return false;" title="Voir l'image PIA02222: Neptune Clouds on the Dark Spot sur le site de la NASA">Voir l'image PIA02222: Neptune Clouds on the Dark Spot sur le site de la NASA.</a></div>
PIA02222: Neptune Clouds on the Dark Spot
<h1>PIA02223: Neptune's Small Dark Spot (D2)</h1><div class="PIA02223" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This bulls-eye view of Neptune's small dark spot (D2) was obtained by Voyager 2's narrow-angle camera. 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 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 Applications.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02223" onclick="window.open(this.href); return false;" title="Voir l'image PIA02223: Neptune's Small Dark Spot (D2) sur le site de la NASA">Voir l'image PIA02223: Neptune's Small Dark Spot (D2) sur le site de la NASA.</a></div>
PIA02223: Neptune's Small Dark Spot (D2)
<h1>PIA02245: Neptune's Blue-green Atmosphere</h1><div class="PIA02245" lang="en" style="width:650px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Neptune's blue-green atmosphere is shown in greater detail than ever before by the Voyager 2 spacecraft as it rapidly approaches its encounter with the giant planet. This color image, produced from a distance of about 16 million kilometers, shows several complex and puzzling atmospheric features. The Great Dark Spot (GDS) seen at the center is about 13,000 km by 6,600 km in size -- as large along its longer dimension as the Earth. The bright, wispy "cirrus-type" clouds seen hovering in the vicinity of the GDS are higher in altitude than the dark material of unknown origin which defines its boundaries. A thin veil often fills part of the GDS interior, as seen on the image. The bright cloud at the southern (lower) edge of the GDS measures about 1,000 km in its north-south extent. The small, bright cloud below the GDS, dubbed the "scooter," rotates faster than the GDS, gaining about 30 degrees eastward (toward the right) in longitude every rotation. Bright streaks of cloud at the latitude of the GDS, the small clouds overlying it, and a dimly visible dark protrusion at its western end are examples of dynamic weather patterns on Neptune, which can change significantly on time scales of one rotation (about 18 hours).<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA02245" onclick="window.open(this.href); return false;" title="Voir l'image PIA02245: Neptune's Blue-green Atmosphere sur le site de la NASA">Voir l'image PIA02245: Neptune's Blue-green Atmosphere sur le site de la NASA.</a></div>
PIA02245: Neptune's Blue-green Atmosphere
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