Thursday 27 August 2020

Asteroid (411165) 2010 DF1 passes the Earth.

Asteroid (411165) 2010 DF1 passed by the Earth at a distance of about 8 223 000 km (20.9 times the average distance between the Earth and the Moon, or 5.36% of the distance between the Earth and the Sun), slightly before 8.00 pm GMT on Thursday 20 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. (411165) 2010 DF1 has an estimated equivalent diameter of 82-260 m (i.e. it is estimated that a spherical object with the same volume would be 82-260 m in diameter), and an object at the upper end of this range 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 350 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater roughly 15 km in diameter and devastation on a global scale, as well as climatic effects that would last decades or even centuries.

Asteroid (411165) 2010 DF1 imaged on 18 August 2020 from London, England. Image is a composite made up of 60 ten second exposures. Asteroid is the point indicated by the red lines, which has moved only slightly over the course of the image gathering, while the longer lines are stars that have moved considerably in the same time. Northolt Branch Observatories/Facebook.

(411165) 2010 DF1 was discovered on 17 February 2010 by the University of Arizona's Kitt Peak-Spacewatch Project at the Steward Observatory in the Catalina Mountains north of Tucson. The designation 2010 DF1 implies that it was the 30th asteroid (asteroid O28 - 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 F1 = 6 + (24 X 1) = 30) discovered in the second half of February 2010 (period 2010 D), while the  longer designation, (411165), indicates that the asteroid was the 411 165th asteroid ever discovered. Asteroids are not given this longer designation immediately, to avoid duplicate or false sightings.

The orbit of (411165) 2010 DF1, and its current position. JPL Small Body Database.

(411165) 2010 DF1 has a 738 day (2.02 year) orbital period, with an elliptical orbit tilted at an angle of 20.1° to the plain of the Solar System which takes in to 0.79 AU from the Sun (79% of the distance at which the Earth orbits the Sun, and slightly outside the orbit of the planet Venus) and out to 2.40 AU (240% of the distance at which the Earth orbits the Sun, and comsiderably outside the orbit of the planet Mars). This means that close encounters between the asteroid and Earth are regular, with the last thought to have happened in August 2018 and the next predicted in August 2022. 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). As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, (411165) 2010 DF1 is also classified as a Potentially Hazardous Asteroid.

See also...















Follow Sciency Thoughts on Facebook.