Asteroid 2020 KF5 passed by the Earth at a distance of about 246 700
km (0.64 times the average distance between the Earth and the Moon, or
0.16% of the distance between the Earth and the Sun), slightly after 12.45 pm
GMT on Thursday 28 May 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 KF5 has an estimated
equivalent
diameter of 2-8 m (i.e. it is estimated that a spherical object
with
the same volume would be 2-8 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 35 km above the ground, with only fragmentary material
reaching the Earth's surface.
The orbit and current position of Asteroid 2020 KF5. The Sky Live 3D Solar System Simulator.
2020 KF5 was discovered on 26 May 2020 (two days 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 KF5 implies that the asteroid was the 146th object (asteroid N1 -
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 F5 = (24 x 5) + 6 = 146) discovered in the second half of May 2020 (period 2020 K - the
year being split into 24 half-months represented by the letters A-Y, with I being excluded).
2020 KF5 has an 645 day (1.77 year) orbital period and an eccentric orbit
tilted at an angle of 1.94° to the plane of the Solar System, which
takes it from 0.85 AU from the Sun (i.e. 85% of the the average distance at
which the Earth orbits the Sun) to 2.07 AU from the Sun (i.e. 207% of
the
average distance at which the Earth orbits the Sun, more than the distance at which 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 thought to have happened in May 2004 and the next predicted
in October 2034.
Asteroid 2020 KF5 also has occasional close encounters with the planet
Mars, which it last came close to in July 1945 is next expected
to
approach again in May 2047.
See also...
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