Asteroid 2014 GJ45 passed by the Earth at a distance of 10 190 000 km (roughly 26.5 times the average distance between the Earth and the Moon) at about 11.35 am GMT on Thursday 17 April 2014. There was no danger of the asteroid hitting us, though were it to do so it would present a realistic threat. 2014 GJ45 is estimated to be between 36 m and 110 m in diameter, and an object towards the upper end of this range would be predicted to be capable of punching straight through the Earth's atmosphere, impacting the planet's surface a causing an explosion roughly 2500 times as large as the Hiroshima Bomb. Such an event would create a crater around 1.5 km wide as well as causing devastation over a much wider area, and resulting in climatic effects that would probably last for several years.
The calculated orbit of 2014 GJ45. JPL Small Body Database Browser.
2014 GJ45 was discovered on 7 April 2014 by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2014 GJ45 implies that the asteroid was the 1134th object (object J45) discovered in the first half of April 2014 (period 2014 G).
2014 GJ45 has a 331 day orbital period, with an elliptical orbit tilted at an angle to the plain of the Solar System which takes in to 0.63 AU from the Sun (63% of the distance at which the Earth orbits the Sun, considerably inside the orbit of the planet Venus) and out to 1.25 AU (25% further away from the Sun than the Earth). This means that close encounters between the asteroid and Earth are fairly common, with the last thought to have happened in August 2013 and the next predicted in April 2015. Although it does cross the Earth's orbit and is briefly further from the Sun on each cycle, 2014 GS1 spends most of its time closer to the Sun than we are, and is therefore classified as an Aten Group Asteroid.
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