Asteroid 2012 DA14

Asteroid 2012 DA14

2012 DA14 is a near earth asteroid with an estimated diameter of about 45 meters (148 ft) and an estimated mass of about 130,000 metric tons. It was discovered on February 23, 2012, by the OAM Observatory, La Sagra in Spain (J75) seven days after passing 0.0174 AU (2,600,000 km; 1,620,000 mi) from Earth on February 16. Calculations show that on February 15, 2013, the distance between the asteroid and Earth will be 0.000228 AU (34,100 km; 21,200 mi).

On January 9, 2013, the asteroid was recovered by Las Campanas Observatory and the observation arc increased from 79 days to 321 days. It is now known that on February 15, 2013 at 19:25 Universal Time the asteroid will pass at a distance of 0.000228 AU (34,100 km; 21,200 mi) from the center-point of Earth,  with an uncertainty region of about 0.000001 AU (150 km; 93 mi).  The asteroid will pass closer than satellites in geosynchronous orbit. The asteroid will not be visible to the naked eye,  but will briefly peak at roughly apparent magnitude 7.4. Goldstone will observe 2012 DA14 from February 16 through February 20.

The 2013 close approach to Earth will reduce the orbital period of 2012 DA14 from 366 days to 317 days. The next notable close approach to Earth will be on 16 February 2046 when the asteroid will pass no closer than 0.0004 AU (60,000 km; 37,000 mi) from the center-point of Earth.

Risks

The asteroid will not impact Earth on February 15, 2013. There is a 1 in 7,692,308,000 chance of 2012 DA14 impacting Earth on 16 February 2110.

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It is rated a low −10 on the Palermo Scale.  (The risk is less than one billionth of the estimated risk of another similarly sized near earth asteroid hitting Earth during that time period. It is estimated that there are more than a million near-Earth asteroids smaller than 100 meters.)

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It rates 0 (No Hazard) on the Torino scale.

If it were to hit Earth, it is estimated that it would produce the equivalent of 2.5 megatons of TNT.  The Tunguska event has been estimated at 3−20 megatons. Asteroids about 50 meters in diameter are expected to impact Earth once every 1200 years or so.

Older risks

In 2012 there was a cumulative 0.033% risk (1 in 3,030) of 2012 DA14 impacting Earth sometime between 2026 and 2069. In 2012 it was also known that the asteroid would pass no closer to Earth's surface than 3.2 Earth radii during the 2013 passage. 

http://en.wikipedia.org/wiki/2012_DA14

Near-Earth - http://neo.jpl.nasa.gov/news/news174.html