Asteroid 2018 LD1 passed by the Earth at a distance of about 601 400 km (1.58 times the average distance between the Earth and the Moon, or 0.02% of the distance between the Earth and the Sun), at about 4.00 pm GMT on Thursday 14 June 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 LD1 has an estimated equivalent diameter of 11-34 m (i.e. it is estimated that a spherical object with the same volume would be 11-34 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 30 and 10 km above the ground, with only fragmentary material reaching the Earth's surface.
The calculated orbit of 2018 LD1. Minor Planet Center.
2018 LD1 was discovered on 5 June 2018 (nine days before its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope. The designation 2018 LD1 implies that the asteroid was the 29th object (object D1) discovered in the first half of June 2018 (period 2018 L).
2019 LD1 has a 929 day orbital period and an eccentric orbit tilted at an angle of 0.35° to the plane of the Solar System, which takes it from 0.91 AU from the Sun (i.e. 91% of he average distance at which the Earth orbits the Sun) to 2.82 AU from the Sun (i.e. 282% 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).
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