Image courtesy of NASA shows an artist's concept of a broken-up asteroid.
Credits: (REUTERS/NASA/JPL-Caltech/Handout )
The speed will be a blinding 8 kilometers per second.
It is called 2012-DA14, an asteroid that NASA scientists have been watching closely in anticipation of Feb. 15, 2013, when the mammoth piece of solid space rock will soar past the Earth a mere 24,000 kms from the planet's surface. It will be passing even lower than the altitude at which many man-made satellites orbit.
And while officials at the U.S. space agency say there is "zero" chance of impact, they still consider it a rare and intimate brush with what will be the largest asteroid to get this close to Earth since NASA began seriously watching them almost 14 years ago.
In fact 2012-DA14 is eerily similar to an asteroid that destroyed hundreds of square miles of forest in remote Siberia a little over a century ago.
"It's the largest object that has come this close to the Earth since we began our ... tracking program." said Lindley Johnson of NASA's Near-Earth Object observation program, who imagined that DA14 would "do some serious damage at ground level" if it were to impact the planet.
His colleague, NEO manager Don Yeomans, gave some perspective of how close DA14 will come: It will pass inside the geosynchronous ring, the area around 34,000 kms above the Earth where communication satellites loom. But the possibility of this potentially-destructive celestial nomad hitting a satellite, he said, is highly unlikely.
But both Yeomans and Johnson said NASA will be watching DA14 closely - and for a long time. While DA14 is a "zero" on NASA's impact risk scale for its near-Earth pass next February, said Yeomans, it has a very "Earth-like orbit" and will pass again in 2020. It is during that second pass the chances of impact increase - albeit ever so slightly.
"In 2013, not a problem. In 2020, almost certainly not a problem, but you can't rule it out," said Yeomans, adding that DA14 has a has a slim chance of around 1 in 77,000 of hitting the Earth in 2020. But then, he added, if an impact were to ever happen, it would probably be in the ocean, and not big enough to cause a tsunami.
When talking about DA14's upcoming pass in 2013, he is quick to draw on the analogy of the Tunguska event, where an asteroid similar in size to DA14 exploded on entry over a remote part of Siberia in 1908, destroying 1,336 square kms of forest, and spreading a wave of heat felt 65 kms away from the impact site.
While DA14 is still too far away to be certain of its specific characteristics, Yeomans estimates that it is 45 meters in diameter and weighs around 120 million kilograms.
And while asteroids can be made of "a wide variety of materials," such as carbon, iron or nickle-iron combinations, BA14 is most likely composed of solid silicate rock.
Yeomans, who says that at DA14's closest approach it will be "an easy target for amateur astronomers who know where to look" with a telescope, says the planet is bombarded with near-Earth asteroids regularly - "basketball"-sized asteroids on a daily basis, and ones the size of small cars almost weekly. But these, he said, burn up before ever coming close to the planet's surface.
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2012 BA14 Just the facts:
Speed during closest approach to earth: 8.2 kms per second.
Mass: Approximately 120 million kilograms.
Size: Approximately 45 meters in diameter.
Distance from earth's surface during closest approach: Approximately 25,000 kms
Components: Silicate rock
Geographic location during closest approach to earth: Above the Indian Ocean, south of Sri Lanka and just south of the equator.
Risk of impact: 0
- Source: Don Yeomans of NASA's Near-Earth Objects Program.