Astronomy Jargon 101: Bolide

In this series, we are looking at astronomy jargon. bolide! is today's topic.

It is a bird! It is a plane! Is it a...bolide?

The wordbolide has two main definitions and never used in a consistent way. The definition of the term hasn't been established by the International Astronomical Union. You have to use context to figure out what the author meant when you encounter the word in the wild.

A bolide is a bright meteor. Different people have different definitions of what exceptionally means. It refers to a meteor that reaches a brightness of at least two full Moons. It refers to a fireball, which is a large object that crashes through the atmosphere and emits flames. Sometimes the word refers to a meteorite that explodes in our atmosphere without hitting the ground.

Geologists have a completely different sense of the word. They use it to describe any rock large enough to leave a crater on the ground. There is disagreement. The Woods Hole Coastal and Marine Science Center uses the word impactor to refer to any impactor of unknown origin. It could be a comet, a stony asteroid, or a metallic asteroid, but until that distinction is made, it is simply a bolide.

bolides refer to some version of large rocks hitting the Earth.