Asteroid
2016 OA passed by the Earth at a distance of 1 734 000 km (4.50 times
the average distance between the Earth and the Moon, or 1.16% of
the average distance between the Earth and the Sun), at about 8.15 am GMT on Monday 18 July 2016. There was no
danger
of the asteroid
hitting us, though had it done so it would have presented no
threat. 2016 OA has an estimated equivalent diameter of 16-49
m (i.e.
it is estimated that a spherical object with the same volume would be 16-49 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 25 and 9 km above the ground, with only fragmentary
material reaching the Earth's surface.
The calculated orbit of 2016 OA. JPL Small Body Database.
2016 OA was discovered on 16 July 2016 (two days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on
Mount Lemmon in the Catalina Mountains north of Tucson. The designation
2016 OA implies that the asteroid was the first object (object A)
discovered in the second half of July 2016 (period 2016 O).
2016 OA has a 1401 day orbital period and an eccentric orbit tilted at an
angle of 1.09° to the plane of the Solar System that
takes it from 0.75 AU from the Sun (i.e. 75% of the average distance at
which the Earth orbits the Sun and slightly outside the orbit of Venus) to 4.15 AU from the Sun (i.e. 4.15% of
the average distance at which the Earth orbits the Sun, considerably
outside orbit of the planet Mars). 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).
See also...
Asteroid 2016 NK22 passes the Earth. Asteroid
2016 NK22 passed by the Earth at a distance of 264 500 km (0.69 times
the average distance between the Earth and the Moon, or 0.18% of
the average distance between the Earth and the Sun), at about 1.15 pm GMT on Monday 11 July 2016. There...
Asteroid 2016 NA passes the Earth. Asteroid
2016 NA passed by the Earth at a distance of 483 100 km (1.26 times
the average distance between the Earth and the Moon, or 0.32% of
the average distance between the Earth and the Sun), slightly before 5.00 pm GMT on Friday 1 July 2016...
Asteroid 2004 KH17 passes the Earth. Asteroid
2004 KH17 passed by the Earth at a distance of 16 990 000 km
(30.2 times the average distance between the Earth and the Moon, or
11.4% of the average distance between the Earth and the Sun), slightly
before 0.20 am GMT on Thursday 2 June...
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