Lunar craters

The competing theories were: Grove Karl Gilbert suggested in 1893 that the Moon's craters were formed by large asteroid impacts.

According to David H. Levy, Shoemaker "saw the craters on the Moon as logical impact sites that were formed not gradually, in eons, but explosively, in seconds.

[5][6] Visible to the naked eye, the impact is believed to be from an approximately 40 kg (88 lb) meteoroid striking the surface at a speed of 90,000 km/h (56,000 mph; 16 mi/s).

In March 2018, the discovery of around 7,000 formerly unidentified lunar craters via convolutional neural network developed at the University of Toronto Scarborough, Canada was announced.

[1] Because of the Moon's lack of water, atmosphere, and tectonic plates, there is little erosion, and craters are found that exceed two billion years in age.

Large craters, similar in size to maria, but without (or with a small amount of) dark lava filling, are sometimes called thalassoids.

[A][13][14] Beginning in 2009 Nadine G. Barlow of Northern Arizona University, the U.S. began to convert the Wood and Andersson lunar impact-crater database into digital format.

The Moon Zoo project within the Zooniverse program aimed to use citizen scientists to map the size and shape of as many craters as possible using data from the NASA Lunar Reconnaissance Orbiter.

[19] Small craters of special interest (for example, visited by lunar missions) receive human first names (Robert, José, Louise etc.).

The crater Webb , as seen from Lunar Orbiter 1 . Several smaller craters can be seen in and around Webb.
Side view of the crater Moltke taken from Apollo 10 .
Lunar craters as captured through the backyard telescope of an amateur astronomer, partially illuminated by the sun on a waning crescent moon.
Lunar craters as captured through the backyard telescope of an amateur astronomer, partially illuminated by the sun on a waning crescent moon.
The lunar crater Eratosthenes (center left) as imaged from Earth by amateur astronomer Joel Frohlich using an 8-inch Schmidt–Cassegrain telescope .