Asteroid 2019 FA passed by the Earth at a distance of about 229 900
km (0.62 times the average distance between the Earth and the Moon, or
0.15% of the distance between the Earth and the Sun), slightly before 1.15 am
GMT on Saturday 16 March 2019. There was no danger of
the asteroid hitting us, though were it to do so it would not have
presented a significant threat. 2019 FA has an estimated
equivalent
diameter of 3-11 m (i.e. it is estimated that a spherical object
with
the same volume would be 3-11 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 30 above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2019 FA. JPL Small Body Database.
2019 FA was discovered on 16 March 2018 (the day of its closest approach to the Earth) by the University of Tokyo's Kiso Observatory. The designation 2019 FA implies that the asteroid was the first object (object A -
in numbering asteroids the letters A-Z, excluding I, are assigned
numbers from 1 to 25, so that A = 1) discovered in the second half of March 2019 (period 2019 F).
2019 FA is calculated to have
an 568 day orbital period and an eccentric orbit
tilted at an angle of 1.10° to the plane of the Solar System, which
takes it from 0.94 AU from the Sun (i.e. 94% of the the average distance
at
which the Earth orbits the Sun) to 1.74 AU from the Sun (i.e. 174% of
the
average distance at which the Earth orbits the Sun, more than the distance at which the planet Mars orbits). 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). This means that close encounters between the asteroid and the Earth are quite common, with the last calculated to have happened in June 2006 and the next predicted for November 2029. The asteroid also has occasional close encounters with the planet Mars, with the last calculated to have occurred in September 1997.
See also...
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