Asteroid 2020 TA passed by the Earth at a distance of about 220 700 km (0.57 times the average distance between the Earth and the Moon, or 0.15% of the distance between the Earth and the Sun), slightly after 11.05 am GMT on Thurday 1 October 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 TA has an estimated equivalent diameter of 15-48 m (i.e. it is estimated that a spherical object with the same volume would be 15-48 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 between 27 and 9 km above the ground, with only fragmentary material reaching the Earth's surface.
2020 TA was discovered on 4 October 2020 (three days after its closest approach to the Earth), by he 0.5-m Asteroid Terrestrial-Impact Last Alert System telescope on Mauna Loa in Hawaii. The designation 2020 TA implies that it was the furst asteroid (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.) discovered in the first half of October 2020 (period 2020 T - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).
2020 TA has a 605 day (1.65 year) orbital period, with an elliptical orbit tilted at an angle of 12.6° to the plain of the Solar System which takes in to 0.87 AU from the Sun (87% of the distance at which the Earth orbits the Sun) and out to 1.92 AU (192% of the distance at which the Earth orbits the Sun, and more than the distance at which the planet Mars orbits the Sun). 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). 2020 TA is calculated to have had two previous encounters with the Earth, in October 2010 and October 2015, with another such event in October 2028, after which no further close encounters are predicted.
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