Asteroid 2014 HP132 passed by the Earth at a distance of about 6 914 000 km (a little under 18 times the average distance between the Earth and the Moon) slightly after 11.00 pm on Thursday 1 May 2014. There was no danger of the asteroid hitting us, but if it had done so it would have presented a genuine risk. 2014 HP132 is calculated to have an equivalent diameter of 68-220 m (that is to say a spherical body with the same volume would be 68-220 m in diameter), and an object towards the upper end of this range would be capable of passing straight through the Earth's atmosphere and hitting the ground, resulting in an explosion around 29 000 times as large as the one caused by the Hiroshima bomb, and the formation of a crater around 3.5 km in diameter. Such an event would cause devastation over a very wide area, and climatic effects that could last decades.
2014 HP132 was discovered on 28 April 2014 (three days before its closest approach to the Earth) by the University of Arizona's Catalina Sky Survey, which is located in the Catalina Mountains north of Tucson. The designation 2014 HP132 implies that it was the 3316th asteroid (asteroid P132) discovered in the second half of April 2014 (period 2014 H).
2014 HP132 has an 855 day orbital period and an eccentric orbit tilted to the plain of the Solar System that takes it from 0.76 AU from the Sun (i.e. 76% of the average distance at which the Earth orbits the Sun) to 2.77 AU from the Sun (i.e. 277% 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).
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