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 chat similar grey form of the female mountain wheatear, from which it also differs in having a grey (not white) rump and completely white outer tail feathers. Its larger size and all-white outer tail feathers prevent confusion with the tractrac or sickle-winged chats. The Karoo chat has "chak-chak" and "trrat-trrat" calls. The Karoo chat builds a cup-shaped nest of straw and leaves on the ground, usually under a bush or shrub. It lays two to four green eggs. This species is monogamous, mating for life. The Karoo chat is usually seen singly or in pairs. It forages from the ground for