|
Followup:
October 7, 2008
for the latest please visit Space Weather
If predictions were correct, asteroid 2008 TC3 hit Earth this morning (Oct. 7th at 0246 UT), exploding in the atmosphere over northern Sudan like a kiloton of TNT and creating a fireball as bright as a full Moon. Most of the 3-meter-wide asteroid would have vaporized in the atmosphere with only small pieces possibly reaching the ground as meteorites.
The following potentially confirming report comes from Jacob Kuiper, General Aviation meteorologist at the National Weather Service in the Netherlands: "Half an hour before the predicted impact of asteroid 2008 TC3, I informed an official of Air-France-KLM at Amsterdam airport about the possibility that crews of their airliners in the vicinity of impact would have a chance to see a fireball. And it was a success! I have received confirmation that a KLM airliner, roughly 750 nautical miles southwest of the predicted atmospheric impact position, has observed a short flash just before the expected impact time 0246 UTC. Because of the distance it was not a very large phenomenon, but still a confirmation that some bright meteor has been seen in the predicted direction. Projected on an infrared satellite-image of Meteosat-7 of 0300 UTC, I have indicated the position of the plane (+) and the predicted impact area in Sudan (0)."
2008 TC3 was discovered on Oct. 6th by astronomers using the Mt. Lemmon telescope in Arizona as part of the NASA-funded Catalina Sky Survey for near-Earth objects. Asteroids the size of 2008 TC3 hit Earth every few months, but this is the first time one has been discovered before it hit.
October 6, 2008
 A small, newly-discovered asteroid named 2008 TC3 is approaching Earth and chances are good that it will hit. Steve Chesley of JPL estimates that atmospheric entry will occur on Oct 7th at 0246 UTC over northern Sudan [ref]. Measuring only a few meters across, the space rock poses NO THREAT to people or structures on the ground, but it should create a spectacular fireball, releasing about a kiloton of TNT in energy as it disintegrates and explodes in the atmosphere. Odds are between 99.8 and 100 percent that the object will encounter Earth, according to calculations provided by Andrea Milani of the University of Pisa. [ephemeris] [3D orbit]
Related Story - Science Centric
A tiny asteroid discovered just hours ago at an Arizona observatory will enter Earth's atmosphere harmlessly at approximately 2:46 AM GMT tonight. There is no danger to people or property since the asteroid will not reach the ground. It is between 3 and 15 feet (1-5 m) in diameter and will burn up in the upper atmosphere, well above aircraft heights. A brilliant fireball will be visible as a result.
'We want to stress that this object is not a threat,' said Dr Timothy Spahr, director of the International Astronomical Union's Minor Planet Centre.
'We're excited since this is the first time we have issued a prediction that an object will enter Earth's atmosphere,' Spahr added. Odds are between 99.8 and 100 percent that the object will encounter Earth, according to calculations provided by Andrea Milani of the University of Pisa.
When a meteoroid (small asteroid) enters the atmosphere, it compresses the air in front of it. That compression heats the air, which in turn heats the object, causing it to glow and vaporise. Once it starts to glow, the object is called a meteor.
'A typical meteor comes from an object the size of a grain of sand,' explained Gareth Williams of the Minor Planet Centre. 'This meteor will be a real humdinger in comparison!'
The meteor is expected to be visible from eastern Africa as an extremely bright fireball travelling rapidly across the sky from northeast to southwest. The object is expected to enter the atmosphere over northern Sudan at a shallow angle.
'We're eager for observations from astronomers near the asteroid's approach path. We really hope that someone will manage to photograph it,' said Williams.
The Minor Planet Centre, which is located at the Harvard-Smithsonian Centre for Astrophysics, serves as the worldwide clearinghouse for asteroid and comet observations. It collects, checks and disseminates observations and calculates orbits.
|
