Tuesday, March 14, 2006

Astro Word of the Day: Bolide

Bolide

Bolides are meteors that have entered the Earth’s atmosphere and are bright enough to cast shadows. They are often observed to have “exploded” and they usually emit a sound right after entry, much like a sonic boom. Bolide is a French term, derived from Latin word for missile, bolis, which originated from Greek boie, to throw or strike.

2 comments:

Bamm said...

Technically, a Bolide is just a meteor whose magnitude is -4.0 or brighter.

Kin Enriquez said...

According to the USGS:

There is no consensus on its definition, but we use it to mean an extraterrestrial body in the 1-10-km size range, which impacts the earth at velocities of literally faster than a speeding bullet (20-70 km/sec = Mach 75), explodes upon impact, and creates a large crater. "Bolide" is a generic term, used to imply that we do not know the precise nature of the impacting body . . . whether it is a rocky or metallic asteroid, or an icy comet, for example.