Asteroid 2020 QX6 passed by the Earth at a distance of about 447 100 km (1.24 times the average distance between the Earth and the Moon, or 0.32% of the distance between the Earth and the Sun), slightly before 4.15 am GMT on Monday 31 August 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 QX6 has an estimated equivalent diameter of 3-10 m (i.e. it is estimated that a spherical object with the same volume would be 3-10 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.
2020 QX6 was discovered on 28 August 2020 (three days before its closest approach to 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 QX6 implies that the asteroid was the 171st object (asteroid X6 - 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 X6 = (24 x 6) + 23 = 171) discovered in the second half of August 2020 (period 2020 Q).
2020 QX6 has a 272 day (0.75) orbital period, with an elliptical orbit tilted at
an angle of 11.2° to the plain of the Solar System which takes in to
0.53 AU from the Sun (53% of the distance at which the Earth orbits the
Sun, and less than the distance at which the planet Venus orbits the Sun) and out to
1.11 AU (25%
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 March this year (2020) and the next predicted
in August 2023. Although it does cross the Earth's
orbit and is briefly
further from the Sun on each cycle, 2020 QX6 spends most of its time
closer to the Sun than we are, and is therefore classified as an Aten
Group Asteroid. 2020 QX6 also
has occasional close encounters with the planet Venus, which it last came close to in January this year and is next predicted to
pass in September 2023.
See also...
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