Saturday 11 April 2020

Asteroid 2015 FC35 passes the Earth.

Asteroid 2015 FC35 passed by the Earth at a distance of about 4 008 000 km (10.4 times the average distance between the Earth and the Moon, or 2.68% of the distance between the Earth and the Sun), slightly before 10.05 am GMT on Saturday 4 April 2020. There was no danger of the asteroid hitting us, though were it to do so it would have presented a considerable threat. 2015 FC35 has an estimated equivalent diameter of 78-250 m (i.e. it is estimated that a spherical object with the same volume would be 78-250 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 35 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater 3.8 km in diameter and devastation on a global scale, as well as climatic effects that would last decades or even centuries.

The calculated orbit of 2015 FC35. JPL Small Body Database.

2015 FC35 was discovered on 17 March 2015 by the University of Hawaii's PANSTARRS telescope. The designation 2015 FC35 implies that it was the 843rd asteroid (asteroid C35 - 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 C35 = 3 + (24 X 35) = 843) discovered in the second half of March 2015 (period 2015 F).

2015 FC35 has a 600 day (1.64 year) orbital period, with an elliptical orbit tilted at an angle of 15.5° to the plain of the Solar System which takes in to 0.84 AU from the Sun (84% of the distance at which the Earth orbits the Sun) and out to 1.94 AU (1.94% of the distance at which the Earth orbits the sun and further from the Sun than the planet Mars). This means that close encounters between the asteroid and Earth are fairly common, with the last thought to have happened in September 2015 and the next predicted in March 2025. 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/2020/04/asteroid-2020-gh-passes-earth.htmlhttps://sciencythoughts.blogspot.com/2020/04/asteroid-2020-go1-passes-earth.html
https://sciencythoughts.blogspot.com/2020/04/asteroid-2011-gm44-passes-earth.htmlhttps://sciencythoughts.blogspot.com/2020/03/asteroid-2020-fx4-passes-earth.html
https://sciencythoughts.blogspot.com/2020/03/asteroid-2020-fp5-passes-earth.htmlhttps://sciencythoughts.blogspot.com/2020/03/asteroid-2000-bo28-passes-earth.html
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