Britannica
Sources used in this answer
Why do multiringed basins look like bull’s-eyes?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
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.
Multiringed basins appear as bull’s-eyes because they are giant impact features formed by the most energetic collisions in the solar system. Their characteristic ringed structure is primarily attributed to the impact-cratering process, specifically during the modification stage that follows the initial excavation.123
As a crater grows in size, the initial parabolic cavity becomes too large to support itself and undergoes a collapse. This process creates complex features, including:3
- Central peaks and rings: Similar to the ripples formed when an object strikes water, large impacts cause a rebound of material that creates central peaks or raised circular rings.3
- Megaterraces: In the largest impacts, discrete, inward-facing, and widely spaced faults form well outside the initial cavity, creating clifflike scarps that face inward.13
While these rings are believed to be a fundamental part of the crater-forming process, some scientific hypotheses suggest they may also be enhanced by post-impact collapse.1