2008 TC 3

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Asteroid
2008 TC 3
Properties of the orbit ( animation )
Orbit type near-Earth asteroid, Apollo-type
Major semi-axis 1.3082  AU
eccentricity 0.3121
Perihelion - aphelion 0.89996 AU - 1.7164 AU
Inclination of the orbit plane 2.5422 °
Sidereal period 547 days
Physical Properties
Medium diameter 3–4 m
Rotation period 99.173 s and 96.988 s
Absolute brightness 30.673 mag
history
Explorer Attorney Kowalski
Date of discovery October 6, 2008
Another name 8TA9D69

(Name for found meteorites: "Almahata Sitta")

Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.
Reconstructed shape and rotation
The orbit of the asteroid near the earth
Calculated impact point

2008 TC 3 (provisional name of the discoverers: 8TA9D69 ) was the first asteroid for which a collision with the earth (entry into the atmosphere ) was correctly calculated in advance. The crash occurred on October 7, 2008 over the Nubian Desert . Months later, fragments of the asteroid ( meteorites ) could be recovered in the crash area.

Discovery, Observation and Prediction

The very small asteroid was discovered by Richard A. Kowalski ( Catalina Sky Survey ) on October 6, 2008, just 20 hours before it collided with Earth , when it was still outside the lunar orbit. After the first report, there were a number of astronomical observations worldwide; these were possible until the entry into the Earth's shadow on October 7th at 03:49 CEST. From the periodic fluctuations in brightness it was concluded that 2008 TC 3 was rotating exceptionally quickly. The tumbling rotations about two axes showed periods of 99.173 and 96.988 seconds. The exact collision course could be calculated from over 500 astrometric measurements. The orbit data of the approximately 4 m large and 80 t heavy asteroid showed that it would crash on October 7, 2008 at 04:46 CEST over the north of Sudan , in the Nubian Desert east of the Nile . Due to the orbit geometry of the asteroid, the entry into the Earth's air envelope was calculated with a low relative speed of 12.8 km / s. The entry angle, based on the horizontal, was calculated to be around 19 °. Because of the small size of the celestial body, no significant damage was to be expected on earth.

crash

An infrasound measurement from Kenya confirmed the entry point and detonation of the asteroid with an estimated energy of 1.1 to 2.1 kT TNT . The explosion occurred at a height of 37 km at 20.8 ° north latitude and 32.2 ° east longitude. Satellite observations also confirmed the entry into the earth's atmosphere at the calculated location. The observations of pilots of a KLM passenger aircraft from a distance of 1,400 km and the recording of a webcam in Egypt from a distance of 725 km also confirmed the entry of the asteroid into the atmosphere. The detected flickering of the light indicated a fragmentation of the asteroid in several phases. At least three eyewitnesses near the Almahata Sitta train station saw a meteor and heard the sound of the explosion minutes later. The traces of smoke left by the asteroid in the sky were filmed and photographed in the morning by eyewitnesses from Wadi Halfa .

Search and Finds

Peter Jenniskens with meteorites in find situation

At first it was assumed that the asteroid had completely burned up in the atmosphere. Peter Jenniskens , scientist at the SETI Institute , and Muawia Shaddad from the University of Khartoum led a search expedition into the potential meteorite fall area in December 2008. On December 6th, 2008, after a systematic search, several fragments of the asteroid were found. The analysis showed that it was a rare, very black, carbon-rich ureilite , which was probably one of the fragile F-class asteroids. The fragments found now bear the official name Almahata Sitta after a train station located near the sites. During the first search, over 280 fragments with a total weight of almost 4 kg were recovered, which were scattered over an area about 30 km long and up to 7 km wide. Newer finds are also offered for sale. Richard A. Kowalski, the discoverer of 2008 TC 3 , received a small fragment of the asteroid . In December 2009 the University of Khartoum carried out a workshop and a new expedition into the crash area, for which interested parties from all over the world could register. During the expedition, another 250 small fragments of the asteroid were found. By January 2010 over 600 meteorites with a total weight of 10.7 kg had been found. The majority of the meteorites had a mass between 1 and 100 grams, with the largest weighing 379 g. The very different composition and density of the meteorites is particularly remarkable . 20% to 30% of the found masses belong to the classes of enstatites or carbonaceous chondrites . It is therefore believed that the original asteroid was made up of various fragments.

Scientific investigations

Because of the so far unique discovery, observation and discovery circumstances, 2008 TC 3 is of particular scientific interest. It was subsequently determined that the asteroid was shaped like a loaf of bread and entered the atmosphere of the earth with the flat side first. Scientists assume that TC 3 was once blown off from a larger object in 2008 . By evaluating and comparing the spectra , it should now be easier to classify other asteroids in space. In the fragments of the asteroid, the scientists identified 18 different amino acids , which supports the assumption that the ingredients for the creation of life could come from asteroids. Also were polycyclic aromatic hydrocarbons discovered, being not yet clear how these complex organic compounds could survive the high temperatures of 1300 ° C, where the asteroid was exposed to billions of years ago. In 2011, the results of scientific studies were published which show that 2008 TC 3 was probably formed from the collision of three different asteroids, whereby the collisions must have been relatively slow (less than 0.5 km / s). Due to the composition of meteorites compared to spectral and train data of known asteroids scientists suspect the origin in the Nysa - Polana -Asteroidenfamilie associated with asteroids of Flora - and Massalia collided -families.

Meaning for the future

The discovery of 2008 TC 3 shows that it is possible to find asteroids that collide with the earth in space and then precisely calculate the place and time of the crash in advance. The correct prediction of asteroid impacts is important in order to be able to take countermeasures or evacuation measures in good time if a large asteroid threatens to hit. For a defense, however, long-term predictions are necessary (in the range of years). For this purpose there are various observation programs such as Lincoln Near Earth Asteroid Research (LINEAR), which are supposed to catalog and research near-earth asteroids. With the support of SETI research , Peter Jenniskens put together the “Next TC3 Consortium”, which has set itself the task of collecting as comprehensive information as possible about upcoming and existing collisions with objects from space.

See also

literature

Web links

Commons : 2008 TC3  - Collection of Images, Videos and Audio Files

Individual evidence

  1. ^ Association Kuffner - Observatory
  2. ↑ astrosurf.com , accessed on June 29, 2009
  3. ^ Shape and rotation of 2008 TC3 , accessed November 27, 2009
  4. ↑ Meteorites: For the first time, hits predicted from space . Image of Science , 12/2008. Konradin Medien GmbH, Leinfelden-Echterdingen. ISSN  0006-2375 .
  5. ↑ BBC (March 25, 2009)
  6. ↑ Don Yeomans ( NASA ): Small Asteroid Predicted to Cause Brilliant Fireball over Northern Sudan, October 6, 2008
  7. ↑ Don Yeomans (NASA): Impact of Asteroid 2008 TC3 Confirmed of October 7, 2008
  8. ↑ Satellite data
  9. ↑ Emily Lakdawalla (Planetary.org): The planetary society (English) of October 10, 2008
  10. ↑ m8 HRV 200810070245 . Archived from the original on February 12, 2012. Retrieved October 27, 2008.
  11. ↑ Steve Chesley, Paul Chodas, Don Yeomans (Near Earth Object Program of NASA): Asteroid 2008 TC3 Strikes Earth: Predictions and Observations Agree (November 4, 2008)
  12. ↑ 2008 TC3 on the trail - Astronomy Picture of the Day of November 8, 2008.
  13. ↑ New Scientist website (article offline)
  14. ↑ NASA: Media Telecon: The Impact and Recovery of Asteroid 2008 TC3 from March 25, 2009
  15. ^ Meteoritical Bulletin Database
  16. ↑ Almahata Sitta 15 - Astronomy Picture of the Day of March 28, 2009.
  17. ↑ NASA Team Finds Riches in Meteorite Treasure Hunt
  18. ↑ Asteroid 2008 TC3 - Almahata Sitta (Sudan) ( Memento from November 6, 2014 in the Internet Archive ) in the webshop of haberer-meteorite.de , accessed on July 3, 2011
  19. ↑ Emily Lakdawalla (The Planetary Society Blog): A piece of an asteroid returns to the telescope that discovered it , accessed October 13, 2009
  20. ↑ Lucy A. McFadden (University of Maryland): Workshop On Asteroid 2008 TC3 (December 5-15 , 2009) , reproduced on the Khartoum University website , Khartoum, Sudan, accessed October 4, 2009
  21. ↑ Martin Borck in the Westfälische Nachrichten , Gronau (Local): In search of the remains of "2008 TC3" , accessed on January 16, 2016
  22. ^ Report of the workshop and expedition. Asteroid 2008 TC3 - Almahata Sitta, Nubian desert, Sudan. In: www.wondersofnature.nl. Wonders of Nature, December 2009, archived from the original on July 23, 2010 ; accessed on July 3, 2013 .
  23. ↑ The recovery of asteroid 2008 TC3 (PDF; 1.6 MB), accessed on July 3, 2011
  24. ↑ Inspecting an asteroid that hit Earth , accessed October 6, 2009 (registration required)
  25. ↑ J. Gayon-Markt, M. Delbo ', A. Morbidelli, S. Marchi, L. Galluccio, C. Ordenovic: On the origin of the Almahata Sitta meteorite and asteroid 2008 TC3 (PDF; 187 kB), accessed on 7 October 2011.
  26. ↑ Rapid Response to the next TC3 Consortium

Coordinates: 20 ° 48 ′ 0 ″  N , 32 ° 12 ′ 0 ″  E