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| A combo shows a sequence of images released by the ESA on July 10, 2010 of the Lutetia asteroid at various distances before the closest approach of the Rosetta spacecraft. The billion-euro (1.25-billion-dollar) European spacecraft got up close and personal with the asteroid as the probe blasts through the Solar System on its way to rendezvous with a comet. The flyby comes halfway in the extraordinary tale of the European Space Agency's Rosetta, launched in 2004 on a 12-year, 7.1-billion-kilometre (4.4-billion-mile) mission. [AFP] |
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The European spacecraft Rosetta performed a fly-by of a massive asteroid on Saturday, the European Space Agency said, taking images that could one day help Earth defend itself from destruction.
Racing through the asteroid belt between Mars and Jupiter at 47,800 kph (29,925 mph), the billion-euro (1.25-billion-dollar) probe flew within 3,200 kms (2,000 miles) of the huge potato-shaped rock, Lutetia.
"The fly-by has been a spectacular success with Rosetta performing fautlessly," ESA said in a statement.
"Just 24 hours ago, Lutetia was a distant stranger. Now, thanks to Rosetta, it has become a close friend," the agency added.
The aim of the fly-by of the asteroid, measuring 134 kms (83.75 miles) in diameter, is to measure Lutetia's mass and then calculate its density, knowledge which could one day be a lifesaver, according to ESA scientists.
If a rogue asteroid enters on a collision course with Earth, knowing its density will help the planet's defenders to determine whether they should try to deflect the rock or, instead, blow it up.
As Rosetta is around half a million kilometres from Earth, the probe's signal and images took 25 minutes to be received.
Once widely dismissed as bland lumps of debris left over from the building of the planets, asteroids have turned out to be intriguingly individual.
They are extremely different in shape and size, from just hundreds of metres (yards) across to behemoths of 100 kms (60 miles) or more, and also vary in mineral flavours.
Most measurements suggest Lutetia is a "C" type of asteroid, meaning that it contains primitive compounds of carbon. But others indicate it could be an "M" type, meaning that it holds metals.
New data proving this could rewrite the theory about asteroid classification.
Metallic asteroids are far smaller than Lutetia: they are deemed to be fragments of far larger rocks that, in the bump and grind of the asteroid belt, were smashed apart.
The fly-by comes halfway through the extraordinary voyage of Rosetta, launched in 2004 on a 12-year, 7.1-billion-kilometre (4.4-billion-mile) mission.
