Which of These BEST Describes the Surface of Callisto, the Outer

Multiple Choice

Which of these BEST describes the surface of Callisto, the outer Galilean moon of Jupiter?

A) very dark, rocky surface with a thin ice frost that occasionally disappears by evaporation when illuminated by the Sun
B) ammonia and methane ice surface with methane clouds above it, making the moon appear very bright
C) ice-covered and heavily cratered surface with a dark coating, maybe of meteoritic dust or hydrocarbon material, making the moon appear dark
D) sulfur-coated surface with molten sulfur lakes and active volcanoes