Asteroid
2016 FB13 passed by the Earth at a distance of 474 500 km (1.23 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 1.35
am GMT on Sunday 3 April 2016. There was no
danger
of the asteroid
hitting us, though had it done so it would have presented no
threat. 2016 FB13 has an estimated equivalent diameter of 9-28 m (i.e.
it is estimated that a spherical object with the same volume would be 9-28 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 33-18 km above the ground, with only fragmentary
material reaching the Earth's surface.
The calculated orbit of 2016 FB13. JPL Small Body Database.
2016 FB13 was discovered on 30 March 2016 (four days before its closest approach to the Earth) by the Dark Energy Camera on the Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory
in La Serena, Chile. The designation 2016 FB13 implies that it was the
327th asteroid (asteroid B13) discovered in the second half of March
2016 (period 2016 F).
2016 FB13 has a 1388 day orbital period and an eccentric orbit tilted at an angle of 0.14° to the plane of the Solar System that takes it from 0.74 AU from the Sun (i.e. 74% of the average distance at which the Earth orbits the Sun, outside the orbit of Venus) to 4.13 AU from the Sun (i.e. 413% 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 means that close encounters between the asteroid and Earth are extremely common, with the last having occurred in September 2012 and the next predicted in March 2076.
This
also means that 2016 FB13 has occasional close encounters with the
planets Mars, Venus and Jupiter. Its next close approach to Venus is predicted to occur in July 2087, the next close
encounter with Mars will happen in April 2072, and the next predicted close encounter with Jupiter will happen in April 2025. Asteroid
orbits that have close encounters with multiple planets are considered
to be quite unstable, as any perturbations can quickly become magnified,
throwing the astroid onto a new orbital path.
See also...
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the average distance between the Earth and the Moon, or 0.44% of
the average distance between the Earth and the Sun), slightlyafter 6.20
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Asteroid 2016 FU6 passes the Earth. Asteroid
2016 FU6 passed by the Earth at a distance of 178 900 km (0.47 times
the average distance between the Earth and the Moon, or 0.12% of
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