Karoo (crater) Karoo (crater) Karoo is an impact crater on the Asteroid 253 Mathilde, named for the Great Karoo Basin, a coal basin in South Africa. It is 33.4 kilometers in diameter and was the most prominent crater seen during NEAR Shoemaker's Flyby of the Asteroid. The critical crater diameter is the scale at which cratering “goes global” and results in a solitary distinct crater. All smaller craters—however large D might be—are local events. Mathilde is thus a particularly interesting case, since it is the largest asteroid imaged at sufficient resolution to show that its topography is clearly exogenic, governed by impacts.
Karoo which is Afrikaans for Little Karoo. The Great Karoo straddles the 30° S parallel on the west of the continent, in a similar position to other semidesert areas on earth, north and south of the equator. It is furthermore in the rainfall shadow of the Cape Fold Mountains along the western coastline. The western "Lower Karoo" (the Tankwa Karoo and Moordenaarskaroo) contain remnants of the Cape Fold Mountains (e.g. the Witteberg and Anysberg Mountains) which give it a moderate hilly appearance, but further east, the Lower Karoo becomes a monotonously flat plain. The "Upper Karoo" has been intruded by dolerite