Asteroid 2020 JU passed by the Earth at a distance of about 12 369 000
km (32.2 times the average distance between the Earth and the Moon, or 8.26% of the distance between the Earth and the Sun), slightly before 9.10 pm
GMT on Thursday 11 June 2020. There was no danger of
the asteroid hitting us, though were it to do so it would have
presented a considerable threat. 2020 JU has an estimated
equivalent
diameter of 120-370 m (i.e. it is estimated that a spherical object with
the same volume would be 120-370 m in diameter), and an object of this size 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 1000-10 000 times as powerful as the
Hiroshima
bomb. Such an impact would result in an impact crater roughly 1.5-5 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 2020 JU. JPL Small Body Database Browser.
2020 JU was discovered on 6 May 2020 by the Wide-field Infrared Survey Explorer
satellite. The
designation 2000 KA
implies that it was the twentieth asteroid (asteroid U)
discovered in the first half of May 2000 (period 2000 J - the
year being split into 24 half-months represented by letters).
2020 JU has a 333 day orbital period, with an elliptical orbit tilted at
an angle of 10.7° to the plain of the Solar System which takes in to
0.85 AU from the Sun (85% of the distance at which the Earth orbits the
Sun) and out to
1.02 AU (2%
further away from the Sun than the Earth). This means that close
encounters between the asteroid and Earth are fairly common, with the
last thought to have happened in January this year (2020) and the next predicted
in May 2029. Although it does cross the Earth's
orbit and is briefly
further from the Sun on each cycle, 2020 JU spends most of its time
closer to the Sun than we are, and is therefore classified as an Aten
Group Asteroid. As an asteroid probably larger than 150 m in diameter
that occasionally comes within 0.05 AU of the Earth, 2020 JU
is also
classified as a Potentially Hazardous Asteroid. The asteroid also has
occasional close encounters with the planet Venus, with the last
having happened in March 2007, and the next predicted for December 2029.
See also...
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