Asteroid
2016 EN156 passed by the Earth at a distance of 601 800 km (1.57 times
the average distance between the Earth and the Moon, or 0.40% of
the average distance between the Earth and the Sun), slightly
before 6.25 am GMT on Saturday 19 March 2016. There was no
danger
of the asteroid
hitting us, though had it done so it would have presented only a minor
threat. 2016 EN156 has an estimated equivalent diameter of 5-16 m (i.e.
it is estimated that a spherical object with the same volume would be 5-16 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 40 km and 25 km above the ground, with only
fragmentary
material reaching the Earth's surface.
2016 EN156 was discovered on 13 March 2016 (six days before its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope on Mount Haleakala on Maui. The designation 2016 EN156 implies that it was the 3913th asteroid (asteroid N156) discovered in the first half of March 2016 (period 2016 E).
2016 EN156 has a 545 day orbital period and an eccentric orbit tilted at an
angle of 3.75° to the plane of the Solar System that takes it from 0.91
AU from the Sun (i.e. 91% of the average distance at which the Earth
orbits the Sun) to 1.70 AU from the Sun (i.e. 170% of the average
distance at which the Earth orbits the Sun, more than the
distance at which Mars orbits the Sun). 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 August 2013 and the next predicted in February 2019. 2015 EN156 also has occasional
close encounters with the planet Mars, with the last calculated to have happened in April 1994 and next predicted in July 2022.
See also...
Asteroid 2016 EM156 passes the Earth. Asteroid
2016 EM156 passed by the Earth at a distance of 531 500 km (1.38 times
the average distance between the Earth and the Moon, or 0.56% of
the average distance between the Earth and the Sun), slightly
before 6.25 am GMT on Wednesday 16...
Asteroid 2016 FC1 passes the Earth. Asteroid
2016 FC1 passed by the Earth at a distance of 167 800 km (0.44 times
the average distance between the Earth and the Moon, or 0.11% of
the average distance between the Earth and the Sun; 147 800 km above the
orbit at which the satellites supporting...
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