Asteroid 2017 VV12 passed by the Earth at a distance of about 714 200
km (1.86 times the average distance between the Earth and the Moon, or
0.48% of the distance between the Earth and the Sun), slightly before 3.15 pm
GMT on Wednesday 15 November 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 VV12 has an estimated
equivalent
diameter of 4-15 m (i.e. it is estimated that a spherical object
with
the same volume would be 4-15 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 43 and 25 km above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2017 VV12. Minor Planet Center.
2017 VV12 was discovered on 14 November 2017 (the day before its closest approach to the Earth) by the University of Arizona's Catalina Sky Survey,
which is located in the Catalina Mountains north of Tucson. The
designation 2017 VV12 implies that it was the 321st asteroid (asteroid V12)
discovered in the first half of November 2017 (period 2017 V).
2017
VV12 has a 767 day orbital period and an eccentric orbit
tilted at an angle of 0.15° to the plane of the Solar System, which
takes it from 0.97 AU from the Sun (i.e. 97% of he average distance at
which the Earth orbits the Sun) to 2.31 AU from the Sun (i.e. 231% of
the
average distance at which the Earth orbits the Sun, more than 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). This means that 2017
VV12 has occasional close encounters with the Earth, which it last came
close to in February 199, and is next predicted to pass in January 2020,
as well as the planet Mars, which it last came close to in April 1997.
See also...
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