Asteroid 2017 VD passed by the Earth at a distance of about 3 801 000
km (9.89 times the average distance between the Earth and the Moon, or 2.54% of the distance between the Earth and the Sun), at about 1.10 am
GMT on Thursday 2 November 2017. There was no danger of
the asteroid hitting us, though were it to do so it would have
presented a significant threat. 2017 VD has an estimated
equivalent
diameter of 120-390 m (i.e. it is estimated that a spherical object
with
the same volume would be 120-390 m in diameter), and an object at the
upper end of this
size range would be predicted to be capable of
passing through the Earth's
atmosphere relatively intact, impacting the ground directly with an
explosion that would be 1000-150 000 times as powerful as the
Hiroshima
bomb. Such an impact would result in an impact crater over 1.8-5.0 km
in
diameter
and devastation on a global scale, as well as climatic effects that
would last years or even decades.
The calculated orbit of 2017 VD. Minor Planet Center.
2017 VD was discovered on 4 November 2017 (two days after its closest approach to the Earth) by the Atlas MLO Telescope at Mauna Loa Observatory in Hawaii. The designation 2017 VD
implies that the asteroid was the fourth object (object D) discovered in the first half of November 2017 (period 2017 V).
2017 VD has a 1433 day orbital period and an eccentric orbit
tilted at an angle of 8.37° to the plane of the Solar System, which
takes it from 0.45 AU from the Sun (i.e. 45% of he average distance at
which the Earth orbits the Sun, and slightly outside the orbit of Mercury) to 4.51 AU from the Sun (i.e. 4.51% of
the
average distance at which the Earth orbits the Sun, slightly more than three times 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). As
an asteroid probably larger than 150 m in diameter that occasionally
comes within 0.05 AU of the Earth, 2017 VD is also
classified as a Potentially Hazardous Asteroid.
See also...
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