Asteroid
2016 NK22 passed by the Earth at a distance of 264 500 km (0.69 times
the average distance between the Earth and the Moon, or 0.18% of
the average distance between the Earth and the Sun), at about 1.15 pm GMT on Monday 11 July 2016. There was no
danger
of the asteroid
hitting us, though had it done so it would have presented no
threat. 2016 NK22 has an estimated equivalent diameter of 2-9
m (i.e.
it is estimated that a spherical object with the same volume would be 2-9 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 over 32 km above the ground, with only fragmentary
material reaching the Earth's surface.
The calculated orbit of 2016 NK22. JPL Small Body Database.
2016 NN22 was discovered on 9 July 2016 (two days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on
Mount Lemmon in the Catalina Mountains north of Tucson. The designation
2016 NN22 implies that the asteroid was the 655th object (object N22)
discovered in the first half of July 2016 (period 2016 N).
2016 NN22 has a 670 day orbital period and an eccentric orbit that
takes it from 0.97 AU from the Sun (i.e. 97% of the average distance at
which the Earth orbits the Sun) to 2.03 AU from the Sun (i.e. 203% of
the average distance at which the Earth orbits the Sun, considerably
outside 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 fairly common, with the
last thought to have happened in October 2014 and the next predicted in June 2038. 2016 NN22 also has occasional close encounters with the planet Mars, with the last having occured in March 2016.
See also...
Asteroid 2016 NA passes the Earth. Asteroid
2016 NA passed by the Earth at a distance of 483 100 km (1.26 times
the average distance between the Earth and the Moon, or 0.32% of
the average distance between the Earth and the Sun), slightly before 5.00 pm GMT on Friday 1 July 2016...
Asteroid 2004 KH17 passes the Earth. Asteroid
2004 KH17 passed by the Earth at a distance of 16 990 000 km
(30.2 times the average distance between the Earth and the Moon, or
11.4% of the average distance between the Earth and the Sun), slightly
before 0.20 am GMT on Thursday 2 June...
Fireball over Arizona. The American Meteor Society has
received reports of a bright fireball meteor being seen over much of
the southwest United States at about 4.00 am local time on Thursday 2
June 2016 (about 11.00 am GMT).
The fireball was seen across Arizona, Utah, New...
See also...
Asteroid 2016 NA passes the Earth. Asteroid
2016 NA passed by the Earth at a distance of 483 100 km (1.26 times
the average distance between the Earth and the Moon, or 0.32% of
the average distance between the Earth and the Sun), slightly before 5.00 pm GMT on Friday 1 July 2016...Asteroid 2004 KH17 passes the Earth. Asteroid
2004 KH17 passed by the Earth at a distance of 16 990 000 km
(30.2 times the average distance between the Earth and the Moon, or
11.4% of the average distance between the Earth and the Sun), slightly
before 0.20 am GMT on Thursday 2 June...Fireball over Arizona. The American Meteor Society has
received reports of a bright fireball meteor being seen over much of
the southwest United States at about 4.00 am local time on Thursday 2
June 2016 (about 11.00 am GMT).
The fireball was seen across Arizona, Utah, New...
Follow Sciency Thoughts on Facebook.
