Scientists at the European Space Agency's Space Operations Centre in Darmstadt, Germany are preparing for a probe to perform a flyby of the largest asteroid ever surveyed by satellite.
The spacecraft, which is called Rosetta, will pass within 3,162 kilometres of the centre of the 100km-wide asteroid 21 Lutetia at a speed of about 54,000 kilometres per hour. It'll take pictures, measure the asteroid's temperature, work out what it's made of, and grab dust particles to see if the asteroid has any kind of atmosphere.
Lutetia orbits between Mars and Jupiter and is thought to consist of material left over from the formation of planets. The idea behind the flyby is to try and find out more about our own origins -- one prominent theory for the formation of life on earth is that it arrived on an asteroid.
Rosetta is conducting the flyby on the way to its main mission goal -- a study of the comet 67P/Churyumov, which it'll intercept in 2014. Following the encounter with 21 Lutetia, it'll shut its systems down for deep space hibernation until it approaches the comet, when it'll spring back into life.
Dr Dan Andrews of the Open University will be at mission control, and told Wired: "Rosetta will be using its suite of instruments to study Lutetia in amazing detail, producing stunning images of a surface battered and cratered since the dawn of time.
"Asteroid Lutetia is an enigmatic body, roughly 100 km across and like all asteroids composed of the ‘rubble’ left over from the formation of the planets -- as such, understanding these mysterious objects orbiting mostly between Mars and Jupiter can shed new light on our own origins."
From there it'll enter orbit around the comet's core, and drop a landing vehicle to try and find out more about its composition, firing a pair of harpoons into its surface during its descent to keep it attached and stop it from bouncing off. It'll then accompany the comet as it approaches the Sun, before ending its mission in 2015.
Andrews added: "Rosetta is Europe’s comet chaser: a 3 tonne spacecraft hurtling through space on a ten-year mission to intercept and rendezvous with comet 67P/Churyumov-Gerasimenko in May 2014, before entering orbit around the 4 km wide nucleus and later releasing a lander to the surface.
"The journey is not simple, and along the way Rosetta has to date flown past Earth three times and Mars once, on each occasion stealing energy from the planet in a ‘gravitational slingshot’, modifying its orbit to closer match that of the comet -- saving fuel in doing so."
Pictures from the fly-by will be appearing on the agency's Rosetta photo gallery from late in the evening on 10 July, 2010. More data will follow in the days afterward. There's also a liveblog from mission control, if you want to follow proceedings in even greater detail.