Thursday, 20 February 2020

Asteroid 2020 DU passes the Earth.

Asteroid 2020 DU passed by the Earth at a distance of about 324 900 km (0.85 times the average  distance between the Earth and the Moon, or 0.22% of the distance between the Earth and the Sun), slightly before 1.20 pm GMT on Thursday 13 February 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 DU has an estimated equivalent diameter of 3-11 m (i.e. it is estimated that a spherical object with the same volume would be 3-11 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 30 km above the ground, with only fragmentary material reaching the Earth's surface.
 
The calculated orbit of 2020 DU. JPL Small Body Database.

2020 DU was discovered on 16 February 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 DU implies that the asteroid was the twentieth object (asteroid A - 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, which means that U = 20) discovered in the second half of February 2020 (period 2020 D).

2020 DU has a 901 day (2.47 year) orbital period, with an elliptical orbit tilted at an angle of 1.57° to the plain of the Solar System which takes in to 0.90 AU from the Sun (90% of the distance at which the Earth orbits the Sun) and out to 2.75 AU (275% of the distance at which the Earth orbits the sun and almost twice as far from the Sun as 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).

See also...

https://sciencythoughts.blogspot.com/2020/02/fireball-meteor-over-arizona.htmlhttps://sciencythoughts.blogspot.com/2020/02/fireball-meteor-over-southern-north-sea.html
https://sciencythoughts.blogspot.com/2020/02/fireball-meteor-over-alberta.htmlhttps://sciencythoughts.blogspot.com/2020/02/asteroid-2020-ca-passes-earth.html
https://sciencythoughts.blogspot.com/2020/02/the-alpha-centaurid-meteor-shower.htmlhttps://sciencythoughts.blogspot.com/2020/02/asteroid-2016-xo23-passes-earth.html
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