What evidence from the careful examination of impact craters provides evidence that Mars had surface water long ago?
A) indistinct rims of many large craters due to water erosion
B) lack of small craters which would have been erased by ancient rainfall
C) channels where water once flowed between crater lakes
D) all of these

Question

Quizplus · Accepted Answer

All of these choices are evidence of Mars having surface water long ago. Indistinct rims of large craters suggest erosion by water, the lack of small craters indicates a smoothing effect of rainfall, and channels between crater lakes indicate the flow of water.

What Evidence from the Careful Examination of Impact Craters Provides