Lunar craters were first noted by Galileo. He thought these craters to be volcanic in nature. For most of that time, various varieties of the volcanic theories were used to understand lunar craters. This was before the discovery of asteroids.
After the discovery of asteroids, it came to be thought that cosmic collisions could have formed lunar craters. Richard Proctor was one of the first astronomers to talk about impact craters in his book that came out in 1873.
In 1893, the American geologist G. K. Gilbert seconded Proctor’s findings after a couple of experiments; he considered the impact of cosmic collisions as the most likely reason for the formation of craters. These findings led to the development of lunar stratigraphy in the 1950s.
Picture Credit : Google
