Asteroid 2015 FF passed by the Earth at a distance of 1 596 000 km (4.15 times the average distance between the Earth and the Moon, or 10.7% of the average distance between the Earth and the Sun), slightly before 8.30 pm GMT on Friday 20 March 2015. There was no danger of the asteroid hitting us, though had it done so it would have presented only a minor threat. 2015 FF has an estimated equivalent diameter of 9-28 m (i.e. it is estimated that a spherical object with the same volume would be 9-28 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 34 and 20 km above the ground, with only fragmentary material reaching the Earth's surface.
Categories: 2015 FF; Apollo Group Asteroids; Asteroids; Near Earth Asteroids; Solar System;