Wednesday 17 June 2020

Asteroid 2020 JU passes the Earth.

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...
 
https://sciencythoughts.blogspot.com/2020/06/fireball-meteor-over-western-australia.htmlhttps://sciencythoughts.blogspot.com/2020/06/water-in-indian-meteor-crater-changes.html
https://sciencythoughts.blogspot.com/2020/06/comet-c2019-k7-smith-reaches-perihelion.htmlhttps://sciencythoughts.blogspot.com/2020/06/asteroid-2020-ld-passes-earth.html
https://sciencythoughts.blogspot.com/2020/06/fireball-meteor-over-southern-ohio.htmlhttps://sciencythoughts.blogspot.com/2020/06/2020-kk7-passes-earth.html
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