Archive:Earth-impact events: Difference between revisions
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'''Potentially Hazardous Asteroids''' ('''PHA''') are [[w:Near-Earth asteroids|Near-Earth asteroids]] that are big enough to cause unprecedented regional devastation if they were to hit the Earth. | '''Potentially Hazardous Asteroids''' ('''PHA''') are [[w:Near-Earth asteroids|Near-Earth asteroids]] that are big enough to cause unprecedented regional devastation if they were to hit the Earth. | ||
On September 29, 2004 the asteroid [[w:4179 Toutatis|4179 Toutatis]] made a particularly close approach (within 4 LD, or [[w:lunar distance (astronomy)|lunar distance]]s) from Earth. The next close approach is November 9, 2008, but it will be five times more distant. | |||
There is some concern that the asteroid [[w:99942 Apophis|99942 Apophis]] could impact earth on April 13, 2036. The probability of a collision is currently esitmated to be 1 in 45,000. These calculations are uncertain due to another close encounter in 2029 which could modify the orbit of the asteroid, making a collision either more or less likely. | |||
'''NEO Earth Close-Approaches''' | '''NEO Earth Close-Approaches''' | ||
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See the NASA/JPL [http://neo.jpl.nasa.gov/ca/ Near Earth Object Program] for up-to-date information. | See the NASA/JPL [http://neo.jpl.nasa.gov/ca/ Near Earth Object Program] for up-to-date information. | ||
== In the news == | == In the news == | ||
Revision as of 00:40, 17 October 2008
Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbits bring them close to Earth's orbit, and which may therefore pose a collision danger.
On October 7, 2008 a meteoroid called 2008 TC3 which was 2 to 5 meters (7 to 16 ft) in diameter entered Earth's atmosphere and burned up before it reached the ground. The object had just been discovered about a day before the impact. It exploded tens of kilometers above the ground with the energy of around one kiloton of TNT, causing a large fireball in the early morning sky over northern Sudan.
Potentially Hazardous Asteroids (PHA) are Near-Earth asteroids that are big enough to cause unprecedented regional devastation if they were to hit the Earth.
On September 29, 2004 the asteroid 4179 Toutatis made a particularly close approach (within 4 LD, or lunar distances) from Earth. The next close approach is November 9, 2008, but it will be five times more distant.
There is some concern that the asteroid 99942 Apophis could impact earth on April 13, 2036. The probability of a collision is currently esitmated to be 1 in 45,000. These calculations are uncertain due to another close encounter in 2029 which could modify the orbit of the asteroid, making a collision either more or less likely.
NEO Earth Close-Approaches
- 2008 TT26 on 2008-Oct-23 miss distance of 3.6 LD
- 2005 VN on 2008-Oct-29 miss distance of 4.1 LD
PHA Earth Close-Approaches
- 1999 AQ10 on 2009-Feb-18 miss distance of 4.4 LD
See the NASA/JPL Near Earth Object Program for up-to-date information.
In the news
- Small Asteroid Predicted to Cause Brilliant Fireball over Northern Sudan - October 6, 2008
- Boulder-Size Asteroid to Be Fireball Over Earth Monday - October 6, 2008
- Impact of Asteroid 2008 TC3 Confirmed - October 7, 2008
- Incoming Asteroid Burned Up in Earth's Atmosphere Right on Time - October 8, 2008
- Little Asteroid Makes a Big Splash - October 9, 2008