Bolide
A bolide (French from the Greek βολίς bolis, "missile" or "to flash"[2][3]) is an extremely bright meteor that explodes in the atmosphere. In astronomy, it refers to a fireball approximately as bright as the full moon, and it is generally considered a synonym of a fireball. In geology a bolide is a very large impactor.
One definition describes a bolide as a fireball reaching an apparent magnitude of −14 or brighter, which is more than twice as bright as the full moon.[4] Another definition describes a bolide as any generic large crater-forming impacting body whose composition (for example, whether it is a rocky or metallic asteroid, or an icy comet) is unknown.[5]
A superbolide is a bolide which reaches an apparent magnitude of −17 or brighter.[4][6] Recent examples of superbolides are the Sutter's Mill meteorite and the Chelyabinsk meteor.
Astronomy[edit]
_-_Meteorite.gif)
The IAU has no official definition of "bolide", and generally considers the term synonymous with fireball, a brighter-than-usual meteor. However, the term generally applies to fireballs reaching an apparent magnitude −14 or brighter.[4] Astronomers tend to use bolide to identify an exceptionally bright fireball, particularly one that explodes (sometimes called a detonating fireball). It may also be used to mean a fireball that is audible.
Superbolide[edit]
Selected superbolide air-bursts events:
- Tunguska event (Russia, 1908)
- 2009 Sulawesi superbolide (Indonesia, 2009)
- Chelyabinsk meteor (Russia, 2013)
Geology[edit]
Geologists use the term bolide in a somewhat different context than astronomers do. In geology, it indicates a very large impactor. For example, the Woods Hole Coastal and Marine Science Center of the USGS uses bolide as a generic term that describes any large crater-forming impacting body of which its origin and composition is unknown, as, for example, whether it was a stony or metallic asteroid, or a less dense, icy comet made of volatiles, such as water, ammonia and methane.[5]
Gallery[edit]
See also[edit]
- Comet Shoemaker–Levy 9 § Impacts
- Earth-grazing fireball
- Meteor procession
- Tollmann's hypothetical bolide
References[edit]
- ^ "We are not Alone: Government Sensors Shed New Light on Asteroid Hazards". Universe Today. Retrieved 12 April 2015.
- ^ http://www.merriam-webster.com/dictionary/bolide
- ^ "bolide". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
- ^ a b c Belton, MJS (2004). Mitigation of hazardous comets and asteroids. Cambridge University Press. ISBN 0521827647.:156
- ^ a b "Introduction: What is a Bolide?". Woodshole.er.usgs.gov. 1 April 1998. Retrieved 16 September 2011.
- ^ Adushkin, Vitaly; Ivan Nemchinov (2008). Catastrophic events caused by cosmic objects. Springer. ISBN 1402064527.:133
External links[edit]
- historic record of bolides that have been witnessed entering the Earth’s atmosphere around the world from 861 through 2012 (B612 Foundation)
- Bolide Events 1994 - 2013 neo.jpl.nasa.gov
|
||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
