Meteorites are not necessarily hot when they reach the Earth’s surface. In fact, many meteorites are found with frost on them. As they enter the atmosphere, having been warmed only by the sun, meteors have a temperature below freezing. The intense heat produced during passage through the upper atmosphere at very high speed then melts a meteor’s outside layer, but molten material is blown off and the interior does not have time to warm appreciably. Most meteorites fall through the relatively cool lower atmosphere for as long as several minutes at subsonic velocity before reaching the ground, giving plenty of time for their exterior to cool off again.[186]