Asteroid 2018 EB4 passed by the Earth at a distance of about 559 000 km (1.45 times the average distance between the Earth and the Moon, or 0.37% of the distance between the Earth and the Sun), at about 6.00 am GMT on Friday 16 February 2018. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2018 EB4 has an estimated equivalent diameter of 16-49 m (i.e. it is estimated that a spherical object with the same volume would be 16-49 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 26 and 9 km above the ground, with only fragmentary material reaching the Earth's surface.
2018 EB4 was discovered on 12 March 2018 (four 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 2018 EB4 implies that it was the 104th asteroid (asteroid B4) discovered in the first half of March 2018 (period 2018 E).
2018 EB4 has a 1292 day orbital period and an eccentric orbit tilted at an angle of 1.46° to the plane of the Solar System, which takes it from 0.96 AU from the Sun (i.e. 88% of he average distance at which the Earth orbits the Sun) to 3.76 AU from the Sun (i.e. 376% of the average distance at which the Earth orbits the Sun, more than twice as far from the Sun as 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 2018 EB4 has occasional close encounters with the planet Jupiter, with the last thought to have occurred in March 1941 next predicted for August 2022.
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