Astrobiologist Caleb Scharf Talks Close Encounters With Meteors

When an estimated 7,000-ton meteor exploded in Earth’s atmosphere on Feb. 15, showering Siberia with debris, it put a spotlight on the fact that Earth is constantly bombarded with the detritus of the solar system. Caleb Scharf, director of astrobiology in Columbia’s Astrophysics Laboratory, says these materials once formed planets and come in every size imaginable—from microscopic grains to giant asteroids that may be miles across. “The bigger they are, the rarer they are and the less and less likely it is for their orbits to ever intersect with ours,” he recently wrote in his Scientific American blog. “It does happen though, and across Earth’s history we’ve been hit by some pretty serious stuff—ask the dinosaurs.” In this video, Scharf discusses meteors, the recent strike in Siberia, defensive options available to us and more.