What makes meteorites so hot that you can't touch them?

Category: Space
Published: December 13, 2012

By: Christopher S. Baird, author of The Top 50 Science Questions with Surprising Answers and physics professor at West Texas A&M University

Meteorites – the rocks from space that land on earth – are cold compared to typical earth temperatures. The reason for this is that they have just come from deep space, which is cold. It is true that when a meteorite falls through the atmosphere, the air shock heats the outer surface until it is vaporized. But there is not enough time for this heat to reach inside the meteorite. In his book "Meteorites and their Parent Planets," Harry Y. McSween states: "Although in some cases fusion crusts may still be warm, the interiors of these objects certainly are not. Meteorites have been stored in the deep freeze of space for eons, an atmospheric heating does not significantly affect their interiors because heat conduction in stones or even iron takes much longer than the minute or so required for atmospheric transit. The Colby (Wisoncsin) and Dharmasala (India) meteorites are reported to have been quickly coated with frost, even though both fell on hot days in midsummer."

Meteorites are cold after plummeting to the earth. Although the impact of the meteorite with the air in the atmosphere generates enough heat to vaporize the outer surface, this heat does not have enough time to reach inside the rock. Public Domain Image, source: Wikipedia.

Topics: air, atmosphere, heat, meteorite, temperature