Asteroid 2012 DA14, which is as large as an Olympic swimming pool, will race past the Earth on Friday at a distance of just 27,700 km (17,200 miles) – the closest ever predicted for an object of that size.
It will pass closer even than the geosynchronous satellites that orbit the Earth, but there is no risk of impacts or collisions.
Its closest approach will be 19:25 GMT.
For regions in darkness around that time, it will be visible using good binoculars or a telescope.
The asteroid orbits the Sun in 368 days – a period similar to Earth’s year – but it does not orbit in the same plane as the Earth.
As it passes – at a blistering 7.8 km/s (17,450 mi/hr) – it will come from “under” the Earth and return back toward the Sun from “above”.
As it does, it will pass over the eastern Indian Ocean, making for the best viewing in Eastern Europe, Asia and Australia.
But keen viewers anywhere can find one of several live streams of the event on the internet, including a feed from the Jet Propulsion Laboratory at NASA, available from 19:00 GMT.
Asteroid 2012 DA14 will race past the Earth on Friday at a distance of just 27,700 km, the closest ever predicted for an object of that size
2012 DA14 was first spotted in February 2012 by astronomers at the La Sagra Sky Survey in Spain – once a fairly small-scale, amateur effort to discover and track asteroids that has in recent years become a significant contributor to our knowledge of these “near-Earth objects”.
They caught sight of the asteroid after its last pass, at a far greater distance.
From their observations, they were able to calculate the asteroid’s future and past paths and predict Friday’s near-miss – which will be the closest the object comes for at least 30 years.
Alan Fitzsimmons of Queens University Belfast said that it is a scientific opportunity not to be missed.
“When asteroids come this close, it’s very important to try to learn about them – it’s become so bright, so it’s so easy to study,” he said.
“We get an additional insight into these small objects, which are the most likely impactors on Earth.”
Asteroid 2012 DA14, a 150-foot space rock orbiting Earth, will pass closer than geostationary satellites to our planet on February next year.
NASA’s Impact Risk report said that the odds of the space rock actually hitting Earth are very low indeed – but on February 15, 2013, it will pass just 17,000 miles from Earth, closer than “geostationary” satellites.
If an asteroid of that size hit Earth, it would cause an explosion similar to a nuclear blast.
Two astronomers from the Observatorio Astronómico de La Sagra in Spain spotted 2012 DA14 in late February and its orbit has been calculated to be very similar to Earth’s.
Some reports suggested that on February 15 next year an impact was a possibility, but U.S astronomer Phil Plait, the creator of the Bad Astronomy blog, has ruled out an impact.
Phil Plait wrote: “Asteroid 2012 DA14 is almost certainly not going to hit Earth next February. And by <<almost certainly>>, I mean it. The odds of an impact are so low they are essentially zero. This does not rule out an impact at some future date, but for now we’re safe.”
Asteroid 2012 DA14, a 150-foot space rock orbiting Earth, will pass closer than geostationary satellites to our planet on February next year
The asteroid will come within 17,000 miles of Earth, which is closer than some of our satellites, but Phil Plait says this is nothing to worry about.
The astronomer adds: “Seventeen thousand miles is well beneath many of our own orbiting satellites. To the best of my knowledge, this is the closest pass of a decent-sized asteroid ever seen before the actual pass itself. However, let’s again be very clear – it will miss. In astronomical terms, 17,000 miles is pretty close, but in real human terms it’s a clean miss.”
After 2013, 2012 DA14’s closest brush with Earth will come in 2020, but Phil Plait said that even then the odds of an impact will be less than the chance of being hit by lightning in your lifetime – 1 in 100,000.
What are the chances of a major impact?
NASA’s latest scan for “impact event” threats used the Wide-field Infrared Survey Explorer, or WISE and took two infrared scans of the entire celestial sky between January 2010 and February 2011.
The scan aimed to find asteroids and comets “near Earth” – i.e. within 120 million miles.
The scan found there are 20,500 asteroids and comets that could destroy a city-sized area within 120 million miles of earth – previously the figure was thought to be 36,000.
NASA says the risk of impact is less than previously thought. The likelihood of a “planet-killer” – the mountain-sized asteroids in the “large-sized” range, above 3,300ft – appears to have fallen more significantly.
There are only 981 of these objects near Earth, and NASA has found 911 of them.