On its icy surface, Uranus's satellite Ariel has smooth valleys with few craters. Other areas are rough with many craters. Based on this, it can be concluded that
A)valleys are young and the rough areas are old.
B)the valleys are old and the rough areas are young.
C)both valleys and rough areas are young.
D)both valleys and rough areas are old.

Question

Quizplus · Accepted Answer

The presence of smooth valleys with few craters suggests that these areas are younger because they have been resurfaced or formed more recently, erasing older craters. The rough areas with many craters are older because they have accumulated more impacts over time.

On Its Icy Surface, Uranus's Satellite Ariel Has Smooth Valleys