Washington, United States of America
GALILEO IMAGE OF JUPITER MOON CALLISTO.
NASA's Galileo spacecraft made these images of Jupiter's moon Callisto
in May 2001 in the highest-ever resolution view of any of the planet's
moons. The spires on the knobby terrain are icy but also contain some
darker dust. As the ice erodes, the dark material apparently slides
down and collects in low-lying areas. Over time, as the surface
continues to erode, the icy knobs will likely disappear, producing a
scene similar to the bottom inset, according to NASA.