Scientists have made an important breakthrough in deciding how to deal with an asteroid impact threat that still faces Earth. They have discovered which materials make up a giant space rock that could just possibly hit us in 2036.
The chance of disaster is rated at only one in 45,000 but has proved impossible to rule out. Any impact on land would wipe out a country the size of France or cause a devastating tsunami if it hit the sea.
Using two giant telescopes in Chile and Hawaii, astronomers found that the cosmic missile, called Apophis, is identical to a rare type of meteorite found on Earth. Such a space rock is called a “Type LL chondrite,” and is rich in the minerals pyroxene and olivine.
The information about the asteroid, which is 270 metres wide and weighs 25 million tons, is vital in helping Nasa and other space organisations to decide how to deal with the deadly threat.
Professor Richard Binzel, of the Massachsetts Institute of Technology, said: “Basic characterisation is the first line of defence. We’ve got to know the enemy. The composition is, I think, finally nailed.”
Apophis will have Earth in its sights twice in the next 30 years. During the first close encounter, in 2029, Apophis will miss us by 22,000 miles, putting it closer than TV and GPS satellites.
But experts fear that the near miss in 2029 will put the asteroid on a direct collision course with our planet seven years later in 2036. It would strike with the force of 65,000 atom bombs.
The US-based Planetary Society has put up a $50,000 prize for whoever comes up with the best scheme to tackle the threat that Apophis poses.
Proposals to prevent an Armageddon-style disaster range from using bombs, lasers or spacecraft to nudge it out of the way to blasting it with nuclear missiles. Earlier this month, UK scientist suggested that a swarm of satellites could focus sunlight onto Apophis to steer it off course. The UK arm of satellite builders EADS Astrium has come up with its own plans for a mission to visit the asteroid and divert it.
The US scientists studied Apophis in visible and infrared light, using the MIT Magellan telescope in Chile and NASA’s Infrared Telescope Facility in Hawaii. The tell-tale signature of its spectrum was found to match the special type of meteorite.
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