Galileo images reveal "eroded" terrain on Callisto
Posted: Thu, Aug 23, 2001, 12:35 PM ET (1635 GMT)
New images from NASA's Galileo spacecraft released Wednesday show evidence of hills on the moon Callisto that appear to be slowly eroding away. The images, taken by Galileo in May when it passed less than 140 km from the surface the moon, show a series of jagged hills with regions of dark dust slumping down their sides. Planetary scientists believe the icy hills may have been formed billions of years ago as either the debris of an impact or the remnants of an impact structure. The dust appears to play the key role in eroding the hills: sunlight warms the dust, which then sublimes the surrounding ice. The images are surprising since Callisto, the outermost of Jupiter's four large Galilean moons, has shown no evidence of geological activity that would reshape its surface, and as a result is the most heavily cratered moon in the solar system.
New images from NASA's Galileo spacecraft released Wednesday show evidence of hills on the moon Callisto that appear to be slowly eroding away. The images, taken by Galileo in May when it passed less than 140 km from the surface the moon, show a series of jagged hills with regions of dark dust slumping down their sides. Planetary scientists believe the icy hills may have been formed billions of years ago as either the debris of an impact or the remnants of an impact structure. The dust appears to play the key role in eroding the hills: sunlight warms the dust, which then sublimes the surrounding ice. The images are surprising since Callisto, the outermost of Jupiter's four large Galilean moons, has shown no evidence of geological activity that would reshape its surface, and as a result is the most heavily cratered moon in the solar system.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
Blue Origin describes plans for increased New Glenn launch rates
Posted: Sat, Oct 17 11:41 AM ET (1541 GMT) |
|
news links
|
|
Thursday, October 22
ESA’s Space Rider Suffers Mishap In Drop Test
Aviation Week — 7:18 am ET (1118 GMT) When Starshield Cut Out, Ukrainian Drones Fell From the Skies
New York Times — 7:17 am ET (1117 GMT) Firefly Aerospace Completes Preliminary Design Review for NASA MoonFall Mission
Firefly Aerospace — 7:17 am ET (1117 GMT) Firefly’s Elytra Lunar Orbiter Completes PDR
Aviation Week — 7:17 am ET (1117 GMT) Musk Is Getting It Wrong on India’s Space Oligarchs
Bloomberg News — 7:14 am ET (1114 GMT) |
