AFTER a decade-long quest spanning 6 billion kilometers, a European space probe will intercept a comet, one of the solar system’s enigmatic wanderers, tomorrow.

    The moment will mark a key phase of the most ambitious project undertaken by the European Space Agency (ESA), a 1.3 billion euros (US$1.75 billion) bid to get to know these timeless space rovers.

    More than 400 million km from where it was launched in March 2004, the spacecraft Rosetta will finally meet up with Comet 67P/Churyumov-Gerasimenko (C-G).

    To get there, Rosetta has had to make four passes of Mars and Earth, using their gravitational force as a slingshot to build up speed, and then entering a 31-month hibernation as light from the sun became too weak for its solar panels.

    It was awakened in January.

    After braking manoeuvres, the three-ton craft should move about 100km from the comet, a navigational feat that, if all goes well, will be followed by glittering scientific rewards.

    “It has taken more than 10 years to get here,” said Sylvain Lodiot, spacecraft operations manager. “Now we have to learn how to dock with the comet, and stay with it for the research months ahead.”

    Astrophysicists believe comets are clusters of the oldest dust and ice found in the solar system, the rubble left from the formation of the planets 4.6 billion years ago.

    Some suggest they could be the key to understanding how the planets coalesced after the sun flared into life.

    One theory is that comets, by bombarding the fledgling earth, helped kick-start life by bringing water and organic molecules.

    Until now, though, explorations of comets have been rare and mainly entailed fly-bys by probes on unrelated missions snatching pictures from thousands of kilometers away.

    Exceptions were the U.S. probe Stardust, which recovered dust snatched from a comet’s wake, while Europe’s Giotto ventured to within 200km of a comet’s surface.

    On Nov. 11, the plan is for Rosetta to move to within a few kilometers of the comet to send down a 100kg refrigerator-sized robot laboratory known as Philae.

    Anchored to the surface, Philae will carry out experiments in cometary chemistry and texture for up to six months. After the lander expires, Rosetta will accompany “C-G” as it passes around the sun and heads out towards the orbit of Jupiter. (SD-Agencies)