Monday 9 February 2015

Asteroid 2015 BF92 passes the Earth.

Asteroid 2015 BF92 passed by the Earth at a distance of 3 267 000 km (8.5 times the average distance between the Earth and the Moon, or 2.2 % of the average distance between the Earth and the Sun), slightly before 10.10 pm GMT on Saturday 7 February 2015. There was no danger of the asteroid hitting us, though had it done so it would have presented minor threat. 2015 BF92 has an estimated equivalent diameter of 30-92 m (i.e. it is estimated that a spherical object with the same volume would be 30-92 m in diameter), and an object towards the upper end of this range would either explode very close to the ground with an energy of about 30 megatonnes of TNT (about 1750 times the energy of the Hiroshima bomb) or directly impact the ground, causing devastation over a wide area and creating a crater almost a kilometer across.

The calculated orbit of 2015 BF92. JPL Small Body Database.

2015 BF92 was discovered on 19 January 2015 (nineteen days before its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope on Mount Haleakala on Maui. The designation 2015 BF92 implies that it was the 2306th asteroid (asteroid F92) discovered in the second half of January 2015 (period 2015 B).

2015 BF92 has an 848 day orbital period and an eccentric orbit tilted at an angle of 6° to the plane of the Solar System, which takes it from 0.82 AU from the Sun (i.e. 82% of the average distance at which the Earth orbits the Sun) to 2.68 AU from the Sun (i.e. 268% of the average distance at which the Earth orbits the Sun, considerably more than the disctance at which the planet Mars orbits the Sun). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between the asteroid and Earth are extremely common, with the next predicted in January 2140.

See also...

Asteroid 2009 DT10 passed by the Earth at a distance of 8 202 000 km (21.34 times the average distance between the Earth and the Moon, or 5.5 % of the average distance between the Earth and the Sun), slightly after 4.14 am GMT on Saturday 7 February...


Asteroid 2015 BX509 passes the Earth.   Asteroid 2015 BX509 passed by the Earth at a distance of 13 610 000 km (35.48 times the average distance between the Earth and the Moon, or 9.1% of the average distance between the Earth and the Sun), slightly before 3.25 pm GMT on Thursday 5 February...



Asteroid 2015 BH514 passed by the Earth at a distance of 8 509 000 km (22.53 times the average distance between the Earth and the Moon, or 5.6 % of the average distance between the Earth and the Sun), slightly before 8.40 pm GMT on Wednesday 4...



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