Asteroid 2017 WY14 passed by the Earth at a distance of about 8 792 000
km (23.2 times the average distance between the Earth and the Moon, or 5.88% of the distance between the Earth and the Sun), slightly after 7.45 am
GMT on Sunday 6 May 2018. There was no danger of
the asteroid hitting us, though were it to do so it would have
presented a significant threat. 2017 WY14 has an estimated
equivalent
diameter of 75-240 m (i.e. it is estimated that a spherical object
with
the same volume would be 75-240 m in diameter), and an object at the
upper end of this range would be predicted to be capable of
passing through the Earth's
atmosphere relatively intact, impacting the ground directly with an
explosion that would be about 30 000 times as powerful as the
Hiroshima
bomb. Such an impact would result in an impact crater over 2.5 km
in
diameter
and devastation on a global scale, as well as climatic effects that
would last years or even decades.
The calculated orbit of 2017 WY14. Minor Planet Center.
2017 WY14 was discovered on 22 November 2017 by the University of Hawaii's PANSTARRS telescope. The designation 2017 WY14
implies that the asteroid was the 724th object (object Y14) discovered in the second half of November 2017 (period 2017 W).
2017 WY14 has a 542 day orbital period and an eccentric orbit
tilted at an angle of 27.7° to the plane of the Solar System, which
takes it from 0.90 AU from the Sun (i.e. 90% of he average distance at
which the Earth orbits the Sun) to 1.70 AU from the Sun (i.e. 170% of
the
average distance at which the Earth orbits the Sun, and further from the Sun than the planet Mars). 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 November 2017 and the next predicted
in November 2020. As an asteroid probably larger than 150 m in diameter
that occasionally comes within 0.05 AU of the Earth, 2006 UF17 is also
classified as a Potentially Hazardous Asteroid. 2017 WY14 also has occasional close encounters with the planet Mars, with the last having occurred in May 2013.
See also...
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