A bolide is an extraterrestrial body that collides with the Earth. It explodes either on impact with the Earth's surface or at low altitude above it, creating a large crater. It is a generic term that does not imply the nature of the impacting body, i.e., rocky or metallic asteroid, icy comet, and so on.

Some scietists suggest that a glancing collision with a planet about the mass of Mars, ca 4.5 billion years ago, may have formed the Moon.

Since the Chicxulub bolide has been established as the event that exterminated the dinosaurs 65 mya, bolides are frequently suggested as causes of major climate changes and mass extinctions. No further bolide-induced extinction events have been securely identified as yet, however.

Noteworthy bolide impacts include:

• Chicxulub crater off the coast of Yucatan
• Barringer crater in Arizona, also known as 'Meteor Crater'
• Tunguska event in Siberia
• Chesapeake Bay impact crater

See also crater.