Asteroid 2020 JB1 passed by the Earth at a distance of about 857 900
km (2.23 times the average distance between the Earth and the Moon, or
0.57% of the distance between the Earth and the Sun), at about 6.40 am
GMT on Sunday 10 May 2020. There was no danger of
the asteroid hitting us, though were it to do so it would not have
presented a significant threat. 2020 JB1 has an estimated
equivalent
diameter of 9-30 m (i.e. it is estimated that a spherical object
with
the same volume would be 9-30 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 33 and 16 km above the ground, with only fragmentary material
reaching the Earth's surface.
2020 JB1 was discovered on 13 May 2020 (three days after its closest approach to the Earth) by the Atlas MLO Telescope at Mauna Loa Observatory in Hawaii. The designation 2020 JB1 implies that the asteroid was the 26th object (object B1 -
in numbering asteroids the letters A-Z, 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 B1 = 24 + 2 = 6) discovered in the first half of May 2020 (period 2020 J).
2020 JB1 has a 474 day (1.30 year) orbital period and an eccentric orbit
tilted at an angle of 1.01° to the plane of the Solar System, which
takes it from 0.75 AU from the Sun (i.e. 75% of he average distance at
which the Earth orbits the Sun) to 1.62 AU from the Sun (i.e. 162% of
the
average distance at which the Earth orbits the Sun, and more than the distance at which the planet Mars orbits the Sun). 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 2020 JB1 has occassional close encounters with the Earth, with the last having happened in May 2010, and the next predicted
in July 2024. The asteroid also has occassional close encounters with the planet Mars, with the next predicted in June 2050.
See also...
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