Crater rim
The crater rim or crater wall of an impact crater , for example a ring mountain on the moon , is created when a massive small body impacts an earth-like planet or a similar solid celestial body by ejecting the highly compressed and exploding material.
Crater formation from impact
A meteoroid or asteroid approaches the surface of the larger celestial body at a speed of 10 to 70 kilometers per second (30 to 200 times the earth's speed of sound ). Upon impact, it penetrates up to 100 meters into the rock, which only takes a few thousandths of a second. In that brief moment, all of its kinetic energy is converted into heat and it explodes. The surrounding material is blown away in a conical shape; at the edge of the resulting hole, part of it forms a wall . If a sufficiently large object or one hits at very high speed, the surface springs back and forms a central mountain . When a ball falls into the water, something similar happens: a drop jumps up in the middle. Incidentally, such experiments can be simulated well with semolina porridge .
example
The lunar crater Theophilus pictured opposite is a 105 km circular depression in the floor of the Earth's moon near the visible center of the moon and about 2 billion years old. It has a wall height of almost 7 km. The terraced interior slopes make it one of the most beautiful moon objects. The asteroid that raised the ring mountain was about 3 miles in size. Due to the material thrown out in the explosion, the crater floor is slightly lower than the surroundings.
