 These include the presence of a field of secondary craters, the lack of additional cratering, preserved impact melt in the crater and that the central peak of the crater has not been buried by sediment.Research published in the journal Icarus has found pits in Tooting Crater that are caused by hot ejecta falling on ground containing ice.The pits are formed by heat forming steam that rushes out from groups of pits simultaneously, thereby blowing away from the pit ejecta.