Asteroid 2020 GH passed by the Earth at a distance of about 125 200
km (0.33 times the average distance between the Earth and the Moon,
0.08% of the distance between the Earth and the Sun, or 350% of the
altitude at which geostationary satalites orbit the Earth, and 307 times
the altitude at which the International Space Station
orbits), slightly before 10.05 pm
GMT on Friday 3 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 GH has an estimated
equivalent
diameter of 3-9 m (i.e. it is estimated that a spherical object
with
the same volume would be 3-9 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 more than 33 km above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2020 GH. JPL Small Body Database.
2020 GH was discovered on 2 April 2020 (the day before its closest encounter with the Earth) by the
University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount
Lemmon in the Catalina Mountains north of Tucson. The designation 2020 GH
implies that the asteroid was the eighth object (asteroid H -
in numbering asteroids the letters A-Y, excluding I, are assigned
numbers from 1 to 24, with a number added to the end each time the
alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc, so that H = (8) discovered in the first half of Aprikl 2020 (period 2020 G).
2020 GH has a 1107 day (3.03 year) orbital period and an eccentric orbit
tilted at an angle of 1.12° to the plane of the Solar System, which
takes it from 0.88 AU from the Sun (i.e. 88% of he average distance at
which the Earth orbits the Sun) to 3.31 AU from the Sun (i.e. 331% of
the
average distance at which the Earth orbits the Sun, and more that twice the distance at which the planet 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 fairly common, with the
last having occurred in March 2017 and the next predicted
in May 20203. 2020 GH also has occassional close encounters with
the planet Mars, with the next such encounter predicted for July this year (2020).
See also...
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