Asteroid 2009 DT10 passed by the Earth at a distance of 8 202 000 km
(21.34 times the average distance between the Earth and the Moon, or 5.5
%
of the average distance between the Earth and the Sun), slightly after 4.14
am GMT on Saturday 7 February 2015. There was no danger of the
asteroid hitting us, though had it done so it would have presented significant threat. 2009 DT10 has an estimated equivalent diameter of 52-160 m
(i.e. it is estimated that a spherical object with the same volume
would be 52-160 m in diameter), and an object towards the upper end of
this range would be expected to be capable of passing through the
atmosphere reasonably intact, impacting the ground in an explosion
equivalent to about 80 megatonnes of TNT (roughly 4700 times the energy
of the Hiroshima bomb) and creating a crator about 2.5 km in diameter.
Such an event would cause devastation over a wide area, and could cause
climatic problems for decades.
The calculated orbit of 2009 DT10. JPL Small Body Database.
2009 was first observed by Siding Spring Observatory on 21 February 2009. The designation 2009 DT10 indicates that it was the 269th asteroid (asteroid T10) discovered in the second half of February 2009 (peroid 2009 D).
2009 DT10 has a 1094 day orbital period and an eccentric
orbit tilted at an angle of 3.9° to the plane of the Solar System, which takes
it from 0.79 AU from the Sun (i.e. 79% of the average distance at which the
Earth orbits the Sun) to 3.37 AU from the Sun (i.e. 3.37% of the average
distance at which the Earth orbits the Sun, considerably more than twice the disctance at which the planet
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 February 2012 this year and the next
predicted in January 2018.
See also...
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(35.48 times the average distance between the Earth and the Moon, or
9.1% of the average distance between the Earth and the Sun), slightly
before 3.25 pm GMT on Thursday 5 February 2015. There...
Asteroid
2015 BH514 passed by the Earth at a distance of 8 509 000 km (22.53
times the average distance between the Earth and the Moon, or 5.6 % of
the average distance between the Earth and the Sun), slightly before
8.40 pm GMT on Wednesday 4...
Asteroid
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2015, enabling scientists at NASA's Deep Space Network antenna at...
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