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.
Ryn Desert can drop to a low of . Many small towns are scattered throughout the Ryn Desert, and population density is between 1 and 15 people per square mile. The Ryn lies in a semi-arid climate zone, and receives very little rainfall. High winds sweep across the desert, and in 2001 a dust storm in the Baltic Sea was determined as originating in the Ryn Desert. A study of long-range dust transportation to the Baltic Sea region—by analyzing dust pollution in Scandinavia, showed that aerosol concentrations there were influenced more by the Ryn Desert region than the Sahara Desert in Africa.