Fly By in Outerspace
The European spacecraft Rosetta has performed a fly-by of a massive asteroid, taking images that could one day help Earth defend itself from destruction.
Racing through the asteroid belt between Mars and Jupiter at 47,800 km/h, the €1 billion ($1.4 billion) probe flew within 3200 kilometres of the huge potato-shaped rock, Lutetia.
”The fly-by has been a spectacular success with Rosetta performing faultlessly,” the European Space Agency said. ”Just 24 hours ago, Lutetia was a distant stranger. Now, thanks to Rosetta, it has become a close friend.”
More than 400 ”fantastic images” showed many craters and details.
”Rosetta opened up a new world which will keep scientists busy for years,” said Holger Sierks of the Max Planck Institute in Germany, who is in charge of the spacecraft’s camera.
The aim of the fly-by of the asteroid, which is 134 kilometres in diameter, is to measure Lutetia’s mass and then calculate its density, knowledge which could one day be a lifesaver, space agency scientists say.
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 blow it up.
As Rosetta is about half a million kilometres from Earth, the probe’s signal and images took 25 minutes to be received.
Most measurements suggest Lutetia is a ”C” type of asteroid, meaning it contains primitive compounds of carbon. But others indicate it could be an ”M” type, meaning 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 mission.
One of the biggest gambles in the history of space exploration, the unmanned explorer is designed to meet up in 2014 with Comet 67/P Churyumov-Gerasimenko 675 million kilometres from home.
The goal is to unlock the secrets of these lonely wanderers of the cosmos, whose origins date back to the dawn of the solar system, some 4.5 billion years ago, before planets existed.
To get to its distant meeting point, Rosetta has had to play planetary billiards for five years, using four ”gravitational assists” from Earth and Mars as slingshots to build up speed.