Flashback to Neptune's moon Triton

Triton, Neptune's largest moon, is one of the "coolest" objects in the solar system, literally, with a surface temperature of minus 235 degrees Celsius (minus 391 degrees Fahrenheit). Voyager 2 discovered that Triton has active geysers.

Voyager mapped only the hemisphere that faces Neptune, but revealed a very young surface scarred by rising blobs of ice (diapirs), faults, and volcanic pits and lava flows composed of water and other ices. The video begins near the western edge of this hemisphere with an approach over cantaloupe terrain and two large smooth walled plains. The video tracks due east for roughly 1500 kilometers over a large province of volcanic pits, calderas and smooth plains.

[media:20090826083650632 align:auto border:0 width:320 height:180 This simulated voyage over the surface of Neptune's large moon Triton was produced using topographic maps derived from images acquired by NASA's Voyager spacecraft during its August 1989 flyby, 20 years ago this week. Click image to see video.]

As can be seen in this video, the surface of Triton is very rugged, scarred by rising blobs of ice (diapirs), faults and volcanic pits and lava flows composed of water and other ices. The surface is also extremely young and sparsely cratered. It may even be younger than the surface of Europa, one of the first objects visited by the Voyager spacecraft 30 years ago this summer, and could be geologically active today.

Although locally very rugged, Triton has no large mountains or deep basins and regional relief is low, a consequence of its high internal heat and the low strength of most ices. The scene is on the order of 500 kilometers (310 miles) across and is taken from a new flyover movie across the equatorial region of Triton commemorating the Voyager 20-year anniversary of this flyby. Vertical relief has been exaggerated by a factor of 25 to aid interpretation.

The video was produced by using a new topographic map of Triton, combined with a 1.65-kilometer resolution image mosaic. Topographic mapping was based on shape-from-shading analysis of the original Voyager images. Vertical relief has been exaggerated by a factor of 25 to aid interpretation.

The raw data from which this product was developed were retrieved from the Planetary Data System's data archives. The video was processed by Paul Schenk (http://www.lpi.usra.edu/lpi/schenk/) at the Lunar and Planetary Institute.

This regional view shows a variety of terrains on Triton, including the smooth volcanic plains in the foreground, formed by icy lavas. Parts of this surface have been eroded, forming mounds and depressions with relief of tens to a few hundred meters (several hundred feet). The round pits and mounds across the center of the scene are probably volcanic explosion or collapse craters, the largest of which (at bottom center) is 250 meters deep (820 feet) and 15 kilometers (about 9 miles) across. Many of these pits are aligned in chains similar to those seen in basaltic volcanic areas on Earth, such as Craters of the Moon National Monument in Idaho, except the lavas on Triton are water and other ices that erupted onto the surface. In the distance is one of two large walled smooth plains of unknown origin. These plains are roughly 200 kilometers (124 miles) across. Credit: NASA/JPL/Universities Space Research Association/Lunar & Planetary Institute




This view shows a close-up of a prominent chain of volcanic features surrounded by smooth volcanic plains formed by lavas or ash deposits of water or other ices, such as methane or ammonia. The smaller pits and domes are typically 10 kilometers (6 miles) across and have relief of no more than a few hundred meters (several hundred feet). The large depressions at the far left and right of the chain are 50 to 80 kilometers (31 to 50 miles) across. Credit: NASA/JPL/Universities Space Research Association/Lunar & Planetary Institute




The rugged terrain in the foreground is Triton's infamous cantaloupe terrain, most likely formed when the icy crust of Triton underwent wholesale overturn, forming large numbers of rising blobs of ice (diapirs). The numerous irregular mounds are a few hundred meters (several hundred feet) high and a few kilometers (a few miles) across and formed when the top of the crust buckled during overturn. The large walled plains are of unknown origin, although the irregular pit in the center of the background walled plain may be volcanic in nature. These plains are approximately 150 meters (93 miles) deep and 200 to 250 kilometers (124 to 155 miles) across. Credit: NASA/JPL/Universities Space Research Association/Lunar & Planetary Institute

Source: Jet Propulsion Laboratory
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