- Original Caption Released with Image:
-
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. The polar frosts were sublimating
because Triton's orbital and rotational motion causes the sun to shine
directly on the polar cap for a period of several decades during Neptune's
and Triton's long austral summer. Though the polar cap was undergoing
"heat death," surface temperatures still were only about 38 K (-391
degrees Fahrenheit).
- Image Credit:
-
NASA/JPL/USGS
Image Addition Date:
-
1998-06-04
|