Bolide

For the Swedish guided missile BOLIDE, see RBS 70.
A bolide – a very bright meteor of an apparent magnitude of −14 or brighter
World map of bolide events (1994–2013)[1]

A bolide (French from the Greek βολίς bolis, "missile" or "to flash"[2][3]) is an extremely bright meteor, especially one 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

Animation of a bolide's atmospheric entry and air-burst

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

Selected superbolide air-bursts events:

Geology

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

Footage of a superbolide exploding over Chelyabinsk Oblast, Russia in 2013.
A bolide from the Geminids meteor shower (SAO RAS, vmag  −3)
Tunguska event of 1908 (imaged by a Soviet expedition in 1927).

See also

References

  1. ↑ "We are not Alone: Government Sensors Shed New Light on Asteroid Hazards". Universe Today. Retrieved 12 April 2015.
  2. ↑ http://www.merriam-webster.com/dictionary/bolide
  3. ↑ "bolide". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
  4. 1 2 3 Belton, MJS (2004). Mitigation of hazardous comets and asteroids. Cambridge University Press. ISBN 0521827647.:156
  5. 1 2 "Introduction: What is a Bolide?". Woodshole.er.usgs.gov. 1 April 1998. Retrieved 16 September 2011.
  6. ↑ Adushkin, Vitaly; Ivan Nemchinov (2008). Catastrophic events caused by cosmic objects. Springer. ISBN 1402064527.:133

External links

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