Asteroid 2020 QG passes the Earth.

Asteroid 2020 QG passed by the Earth at a distance of about 9300 km (0.02 times the average distance between the Earth and the Moon, or 0.01% of the distance between the Earth and the Sun, which is slighly less than 23 times the height at which the International Space Station orbits the Earth, but less than a quater of the height of satellites in geostationary orbits), slightly before 4.10 am GMT on Sunday 16 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 QG has an estimated equivalent diameter of 2-6 m (i.e. it is estimated that a spherical object with the same volume would be 2-6 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 36 km above the ground, with only fragmentary material reaching the Earth's  surface.

 

Image of 2020 QG made on 16 August 2020 from the Zwicky Transient Facility at Palomar Observatory in Southern California. Asteroid is elongate as it has moved over the course of the exposure. Wikimedia Commons/National Science Foundation/Caltech/NASA.

 

2020 QG was discovered on 14 August 2020 (the day of after its closest approach to the Earth) by the Zwicky Transient Facility at Palomar Observatory. The designation 2020 QG implies that the asteroid was the 7th object (asteroid G - 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 G = 7) discovered in the second half of August 2020 (period 2020 Q).

The orbit of 2020 QG, and its current position. JPL Small Body Database.

2020 QC has a 990 day (2.71 year) orbital period, with an elliptical orbit tilted at an angle of 5.47° to the plain of the Solar System which takes in to 1.00 AU from the Sun (the distance at which the Earth orbits the Sun) and out to 2.90 AU (290% of the distance at which the Earth orbits the Sun, and outside the orbit of the planet Mars). This means that close encounters between the asteroid and Earth are fairly common, with the the next predicted in May 2028. 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...

 

 

 

Follow Sciency Thoughts on Facebook.