Bolide

The term Bolide is generally used in reference to a meteor which explodes on or near Earth. However the USGS uses the term when the composition of the exploding object in not known for certain. They further narrow their usage to mean it as an extraterrestrial object between 1 and 10 kilometers in size, which impacts the Earth at a velocity between 20 and 70 kilometers per second thereby creating a large crater.

One of the most famous bolide cases is the Tunguska Event that occurred in Russia during June 1908. The Tunguska Event has also been a topic of study among ufologists who point out that because there is some evidence that the meteor responsible for the Tunguska Event changed course prior to exploding, it may have actually been a damaged UFO.