Asteroid 2019 DB passed by the Earth at a distance of about 980 800 km (2.56 times the average distance between the Earth and the Moon, or 0.66% of the distance between the Earth and the Sun), slightly before 6.10 pm GMT on Sunday 24 February 2019. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2019 DB 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 15 km above the ground, with only fragmentary material reaching the Earth's surface.
2019 DB was discovered on 26 February 2018 (two days after its closest approach to the Earth) by the Zwicky Transient Facility at Palomar Observatory in California. The designation 2019 DB implies that the asteroid was the second object (object B - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, so that B = 2) discovered in the second half of February 2019 (period 2019 D).
2019 DB has a 572 day orbital period and an eccentric orbit tilted at an angle of 9.08° to the plane of the Solar System, which takes it from 0.97 AU from the Sun (i.e. 97% of the the average distance at which the Earth orbits the Sun) to 1.72 AU from the Sun (i.e. 172% of the average distance at which the Earth orbits the Sun, and outside the orbit of 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 common, with the last having occurred in March 2008 and the next predicted in January 2020.
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