Multiringed basin

Multiringed basin, any of a class of geologic features that have been observed on various planets and satellites in the solar system. A multiringed basin typically resembles a bull’s-eye and may cover an area of many thousands of square kilometres. The outer rings of the basins are clifflike scarps that face inward. Because of the gradation of smaller examples into ordinary craters and because of the apparent ejecta-blanket patterns of radially striated terrain surrounding them,...