Asteroid
2004 BG41 passed by the Earth at a distance of 11 530 000 km (30
times the average distance between the Earth and the Moon, or 7.7% of
the average distance between the Earth and the Sun), slightly before 8.30 am on Friday November 2015. There was no danger of the asteroid
hitting us, though had it done so it would have presented only a minor
threat. 2004 BG41 has an estimated equivalent diameter of 25-78 m (i.e.
it is estimated that a spherical object with the same volume would be
25-78 m in diameter), and an object of this size would be expected to
explode in an airburst (an explosion caused by superheating from
friction with the Earth's atmosphere, which is greater than that caused
by simply falling, due to the orbital momentum of the asteroid) in the
atmosphere between 18 and 1 km above the ground, with only fragmentary
material reaching the Earth's surface, though an object at the upper end
of this range would explode with the equivalent energy to about 25
megatons of TNT (roughly 1470 times the energy released by the Hiroshima
bomb explosion), so being directly underneath it might be rather
unpleasant.
The calculated orbit of 2015 BG41. JPL Small Body Database.
2004 BG41 was discovered on 22 January 2004 by the Massachusetts Institute of Technology's Lincoln Near Earth Asteroid Research Laboratory in Socorro, New Mexico.
The designation 2004 BG41 implies that it was the 1032nd asteroid (asteroid G41) discovered in the second half of (period 2004 B).
2004 BG41 has a 1455 day orbital period and an eccentric orbit tilted at an angle of 2.97° to the plane of the Solar System that takes it from 0.98 AU from the Sun (i.e. 98% of the average distance at which the Earth orbits the Sun) to 4.04 AU from the Sun (i.e. 404% of the average distance at which the Earth orbits the Sun, considerably more than twice the distance at which 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 also means that close encounters between 2004 BG41 and the Earth are quite common, with the most recent having happened in December 2011 and the next predicted for November 2019.
See also...
Asteroid 2015 VE65 passes the Earth. Asteroid
2015 VE65 passed by the Earth at a distance of 18 410 000 km (47.9 times
the average distance between the Earth and the Moon, or 12.3% of the
average distance between the Earth and the Sun), slightly after 4.10 pm
GMT on Monday 23...
Asteroid 2015 WP2 passes the Earth. Asteroid
2015 WP2 passed by the Earth at a distance of 229 800 km (0.6
times the average distance between the Earth and the Moon, or 0.16% of
the average distance between the Earth and the Sun; but 575.4 times as far from the Earth as the International...
Asteroid 2015 VV2 passes the Earth. Asteroid
2015 VV2 passed by the Earth at a distance of 6 623 000 km (17.2
times the average distance between the Earth and the Moon, or 4.43% of
the average distance between the Earth and the Sun), slightly after
10.30
pm on Wednesday 18 November 2015...
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