How does an asteroid or comet create a meteorite crater?

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four impact craters — Meteorite crater Four impact craters of the same size (30 km [20 miles] in diameter) imaged by spacecraft on different solid bodies of the solar system and reproduced at the same scale. They are (clockwise from upper left) Golubkhina crater on Venus, Kepler crater on the Moon, an unnamed crater on Jupiter's moon Ganymede, and an unnamed crater on Mars. The images are oriented such that the craters appear illuminated from the left; the Venusian crater is imaged in radar wavelengths, the others in visible light.

When an asteroid or comet strikes a planetary surface at hypervelocity—typically tens of kilometers per second—it creates a meteorite crater through a process more akin to an atomic bomb explosion than a simple mechanical hole.1

The formation follows a specific sequence:

Impact and Shock: Upon contact, shock waves propagate into both the surface and the object, vaporizing the meteorite and creating zones of melted and crushed material.1
Excavation: A subsequent release wave generates pressure gradients that project material upward and outward, forming a parabolic bowl. This excavated material forms an ejecta blanket around the rim.1
Modification: In smaller, simple craters, the process ends here. However, larger craters undergo a modification stage where the initial cavity collapses under its own weight. This can result in a flat floor, a central peak, or internal rings caused by the rebound of subsurface material, as well as faulting along the inner rims.1

The resulting landform is determined by the scale of the impact, with the largest structures known as impact basins.1