Why do planets like Mars and Mercury have many large meteorite impact craters on their surface?
The primary reason is from a lack of weathering. Mercury has no atmophere and therefore no weather to erode large craters (by wearing down the rims and filling in the hole with sediments and dust). Mars has some atmosphere and does have weathering, which is why it looks less like the Moon and Mercury and more like the deserts of the Earth. Mars does have a large number of large impact craters, though all of them appear to be extremely old and all are highly weathered (compared to those on the Moon and Mercury). Earth has probably been struck by more large asteroids/meteorites than Mars, the Moon, or Mercury. Yet few large impact craters are detectable. The first reason is the weathering. Compared with the other inner planets, Earth has “severe” weather which over millions of years erodes away mountains, hills, and crater rims and fills in canyons, valleys, and crater floors. In addition, since 3/4 of the Earth is covered with water, approximately 3/4 of all craters form in the ocean (o
