Why does Mercury have more craters than the other planets?

All of the planets in our Solar System have had a lot of craters. This was especially true in the past when there were many more asteroids traveling in our solar system than there are today. On planets like Venus, Earth, and Mars, we do not see as many craters because most of them have been eroded away by wind, rain, volcanic activity, and other forces. On the giant gas planets, Jupiter, Saturn, Uranus, and Neptune, we do not see any craters because there is no visible solid surface for the meteors to hit. On Mercury, where there is no atmosphere, there is no weather to erode away the craters, so most of the craters are still visible.


Learn about IRAS, the first infrared telescope launched into Earth's orbit!