Asteroid 2017 VA passed by the Earth at a distance of about 1 116 500
km (2.99 times the average distance between the Earth and the Moon,
0.75% of the distance between the Earth and the Sun), slightly before 7.40 pm
GMT on Saturday 28 October 2017. There was no danger of
the asteroid hitting us, though were it to do so it would not have
presented a significant threat. 2017 VA has an estimated
equivalent
diameter of 26-82 m (i.e. it is estimated that a spherical object
with
the same volume would be 26-82 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 20 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 exploding would release roughly 1500 times as much energy as the Hiroshima bomb, being directly underneath such an explosion would be fairly unpleasant.
The calculated orbit of 2017 VA. Minor Planet Center.
2017 VA was discovered on 1 November 2017 (four days after its closest approach to the Earth) by the Atlas MLO Telescope at Mauna Loa Observatory in Hawaii. The designation 2017 VA
implies that the asteroid was the first object (object A) discovered in the first half of November 2017 (period 2017 V).
2017 VA has a 1298 day orbital period and an eccentric orbit
tilted at an angle of 4.72° to the plane of the Solar System, which
takes it from 0.90 AU from the Sun (i.e. 90% of he average distance at
which the Earth orbits the Sun) to 3.76 AU from the Sun (i.e. 3.76% of
the
average distance at which the Earth orbits the Sun, more than twice the
distance at which the planet Mars orbits). 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...
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