Asteroid 2019 FB passed by the Earth at a distance of about 1 142 400
km (2.98 times the average distance between the Earth and the Moon, or
0.76% of the distance between the Earth and the Sun), at about 4.05 am
GMT on Friday 15 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 FB has an estimated
equivalent
diameter of 12-39 m (i.e. it is estimated that a spherical object
with
the same volume would be 12-39 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 30 and 12 km above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2019 FB. JPL Small Body Database.
2019 FB was discovered on 16 March 2018 (the day after its closest approach to the Earth) by the Atlas MLO Telescope at Mauna Loa Observatory in Hawaii. The designation 2019 FB implies that the asteroid was the second object (object B -
in numbering asteroids the letters A-Z, excluding I, are assigned
numbers from 1 to 25, so that B = 2) discovered in the second half of March 2019 (period 2019 F).
2019 FB has an 1275 day orbital period and an eccentric orbit
tilted at an angle of 3.16° to the plane of the Solar System, which
takes it from 0.97 AU from the Sun (i.e. 97% of the the average distance
at
which the Earth orbits the Sun) to 3.63 AU from the Sun (i.e. 363% of
the
average distance at which the Earth orbits the Sun, or more than twice 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).
See also...
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