Asteroid 2020 GO1 passed by the Earth at a distance of about 69 000
km (0.18 times the average distance between the Earth and the Moon, 0.05% of the distance between the Earth and the Sun, or 192% of the altitude at which geostationary satalites orbit the Earth, and 40 times the altitude at which the International Space Station orbits), slightly before 7.10 pm
GMT on Wednesday 1 April 2020. There was no danger of
the asteroid hitting us, though were it to do so it would not have
presented a significant threat. 2020 GO1 has an estimated
equivalent
diameter of 5-17 m (i.e. it is estimated that a spherical object
with
the same volume would be 5-17 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 40 and 24 km above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2020 GO1. JPL Small Body Database.
2020 GO1 was discovered on 2 April 2020 (the day after 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 2020 GO1 implies that it was the 38th asteroid (object O1 -
in numbering asteroids the letters A-Y, excluding I, are assigned
numbers from 1 to 24, so that O1 = (24 x 1) + 14 = 38)
discovered in the first half of April 2020 (period 2020 G).
2020 GO1
has an 709 day (1.94 year) orbital period and an eccentric orbit
tilted at an angle of 8.34° to the plane of the Solar System, which
takes it from 1.00 AU from the Sun (i.e. the average distance
at
which the Earth orbits the Sun) to 2.16 AU from the Sun (i.e. 216% of
the
average distance at which the Earth orbits the Sun, and further from from the Sun than 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). This means that close
encounters between the asteroid and Earth are fairly common, with the next predicted
in February 2022.
See also...
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