Asteroid 2019 NE2 passed by the Earth at a distance of about 11 405 000 km (29.7 times the average distance between the Earth and the Moon, or 7.62% of the distance between the Earth and the Sun), at about 2.15 am GMT on Thursday 11 July 2019. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. 2019 NE2 has an estimated equivalent diameter of 120-360 m (i.e. it is estimated that a spherical object with the same volume would be 120-360 m in diameter), and an object of this size would be predicted to be capable of passing through the Earth's atmosphere relatively intact, impacting the ground directly with an explosion that would be between about 1200 and 120 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater between 1.5 and 5 km in diameter and devastation on a global scale, as well as climatic effects that would last decades or even centuries.
The calculated orbit of 2019 NE2. JPL Small Body Database.
2019 NE2 was discovered on 4 July 2019 (seven days before its closest approach to the Earth) by the Atlas MLO Telescope at Mauna Loa Observatory in Hawaii. The designation 2019 NE2 implies that the asteroid was the 53rd object (object E2 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, so that E2 = (24 x 2) + 5 = 53) discovered in the first half of July 2019 (period 2019 N).
2019 NE2 has an 831 day orbital period and an eccentric orbit tilted at an angle of 8.48° to the plane of the Solar System, which takes it from 0.47 AU from the Sun (i.e. 47% of he average distance at which the Earth orbits the Sun, inside the orbit of the planet Venus) to 2.99 AU from the Sun (i.e. 2.99% of the average distance at which the Earth orbits the Sun, which is almost twice the distance at which the planet Mars orbits). 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 extremely common, with the last having occurred in February 2006 and the next predicted in January 2022. As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, 2019 NE2 is also classified as a Potentially Hazardous Asteroid. 201NE2 also has occasional close encounters with the planet Jupiter, with the last having occurred in March 2008, and the next predicted for December 2021.
Follow Sciency Thoughts on Facebook.