Asteroid 2017 EV passed by the Earth at a distance of 1 068 000 km (2.78
times the average distance between the Earth and the Moon, 0.71% of
the average distance between the Earth and the Sun), slightly before 7.35 pm GMT
on Sunday 5 March 2017. There was no danger of the asteroid
hitting us, though had it done so it would have presented no threat.
2017 EV has an estimated equivalent diameter of 8-26 m (i.e. it is
estimated that a spherical object with the same volume would be 8-26 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 35 and 20 km above the ground, with only fragmentary material
reaching the Earth's surface.
The calculated orbit of 2017 EV. Minor Planet Center.
2017 EV was discovered on 4 March 2017 (the day before its closest encounter with the Earth) by the University of Arizona's Catalina Sky Survey,
which is located in the Catalina Mountains north of Tucson. The
designation 2017 EV implies that it was the 21st asteroid (asteroid V)
discovered in the first half of March 2017 (period 2017 E).
2017 EV is calculated to have a 592 day orbital
period and an elliptical orbit tilted at an angle of 7.06° to the plain of the
Solar System that takes it from 0.92 AU from the Sun (i.e. 92% of the average
distance at which the Earth orbits the Sun) to 1.82 AU from the Sun (i.e. 183%
of the average distance at which the Earth orbits the Sun, considerably 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 close encounters between the
asteroid and Earth are extremely common, with the last having occurred
in April 2017 and the next predicted in March 2015. 2017 EV also has frequent close encounters with the
planet Mars, with the last calculated to have happened in February 2011 and the next predicted for May 2022.
See also...
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