Asteroid 2012 DA14 , 150ft across is set to whizz by Earth
February 6, 2013 in Science
Asteroid is set to whizz by Earth INSIDE orbit of communication satellites
- Space rock 150ft across set to whizz by just after Valentine’s Day
- It will miss our home planet by just 17,200 miles – close in cosmic terms
- An impact would be equivalent to 2.25 megaton atom bomb
Planet Earth is set to have a very close encounter with an asteroid the day after Valentine’s Day.
The asteroid – which goes by the name of 2012 DA14 – will miss our planet by just 17,200 miles, which is a near miss in space terms.
The asteroid, which is about 150ft across, will come closer to Earth than the ring of geosynchronous satellites, which are in orbit about 22,200 miles above the Earth.
THIS IS WHAT HAPPENS WHEN AN ASTEROID HITS: THE 1908 TUNGUSKA EVENT
On June 30 1908, in a remote part of Russia, a fireball was seen streaking across the daytime sky.
This event – now known as the Tunguska event – is believed to have been caused by an incoming meteor which exploded in the atmosphere.
Evenks natives and Russian settlers in the hills north-west of Lake Baikal reported a column of bluish light, nearly as bright as the sun, moving across the sky.
About 10 minutes later, there was a flash and a sound similar to artillery fire.
Eyewitnesses closer to the explosion reported the sound source moving east to north.
The sounds were accompanied by a shockwave that knocked people off their feet and broke windows hundreds of miles away.
The majority of witnesses reported only the sounds and the tremors rather than the sighting of the explosion.
The explosion registered on seismic stations across Eurasia.
In some places the shock wave would have been equivalent to an earthquake of 5.0 on the Richter scale.
It also produced fluctuations in atmospheric pressure strong enough to be detected in the UK.
Over the next few days, night skies in Asia and Europe were aglow – and all of this came from a meteorite exploding some four to six miles above the Earth’s surface.
Says Don Yeomans, manager of the Near-Earth Object Office at NASA’s Jet Propulsion Laboratory: ‘The generally agreed upon theory is that on the morning of June 30, 1908, a large space rock, about 120 feet across, entered the atmosphere of Siberia and then detonated in the sky.’
Although the asteroid is small, if it were on a collision course with Earth, it would produce the equivalent of 2.5 megatons of TNT.
And this is just one of some 500,000 rocks circling the Earth.
The good news is that scientists say that that isn’t enough to wipe out life on the planet – but it could wipe out a city the size of Greater London.
However, a miss is as good as a mile, and unless you’re specifically looking for it, you almost certainly won’t see the asteroid.
NASA says that it won’t be bright enough to see with the naked eye, but that a good pair of binoculars or a telescope should be able to pick it out.
On the 15th, said NASA, the asteroid will travel rapidly from the southern evening sky into the northern morning sky, with its closest Earth approach occurring about 19:26 UTC when it will achieve a magnitude of less than seven, which is somewhat fainter than naked eye visibility.
About four minutes after its Earth close approach, there is a good chance it will pass into the Earth’s shadow for about 18 minutes or so before reappearing from the eclipse.
When travelling rapidly into the northern morning sky, 2012 DA14 will quickly fade in brightness.
The best view for astronomers will be from Indonesia, says NASA, while stargazers in Eastern Europe, Asia and Australia should also be able to get a good look at the space rock as it whizzes past us at a speed of 17,400mph.
The asteroid was discovered only last year, by astronomers in southern Spain.
The team was operating from the La Sagra Sky Survey observatory near Granada in Spain. The observatory uses automated telescopes to track small asteroids and comets.
2012 DA14 was discovered after the astronomers decided to search areas of the sky where asteroids are not usually seen.
Its orbital period around the sun is very close to our own, at 368 days, and it has made a close approach every year.
This year’s is the closest, say scientists - and the good news is that this is the closest it will get to Earth for at least three decades.
Dr Gerhard Drolshagen, a near-Earth object observer from the European Space Agency’s Space Situational Awareness (SSA) office, said: ‘In future times the possibility of a collision cannot be completely excluded. It is highly unlikely, but the chance is greater than zero.’
The asteroid’s next very close shave with Earth will be in 2046, when it will squeak by us at a distance of 37,000 miles.
And there’s another close encounter in 97 years’ time, on February 16 2110, when the chance that it will hit the Earth is 1 in 7,692,308,000.
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