DARMSTADT, Germany — Turning what seemed like a science fiction tale into reality, an unmanned probe swung alongside a comet Wednesday after a 4-billion-mile chase through space over the course of a decade.
Europe's Rosetta probe will orbit and study the giant ball of dust and ice as it hurtles toward the sun and, if all goes according to plan, drop a lander onto the comet in November.
Rosetta turned up as expected for its "rendezvous" with comet 67P/Churyumov-Gerasimenko between the orbits of Mars and Jupiter. The incredible trip, launched March 2, 2004, marks a milestone in mankind's effort to understand the mysterious shooting stars that periodically flash past Earth.
Although the moon, Mars and even asteroids have been visited, no spacecraft has yet gotten so close to a comet.
Rosetta will now spend several months observing 67P from a safe distance of up to 60 miles. This will give scientists time to find a safe place to land Rosetta's sidekick, Philae, on 67P's icy surface, which recent pictures show is porous, with steep cliffs and boulders as big as houses.
Even if the landing fails, Rosetta itself will remain in the comet's orbit until at least the end of 2015, gathering reams of data with its 11 on-board sensors. As 67P gets closer to the sun it will begin to fizz and release the cloud of dust and ice that most people associate with comets.
"We're going to have a ringside seat to see, for the first time, a comet turn into a comet, to develop its tail and explain what for centuries mankind has been puzzled by," said David Southwood, a former president of the Royal Astronomical Society, who was involved with the Rosetta mission from the start.
Overall, scientists hope the $1.74 billion mission will help them learn more about the origins of comets, stars, planets and maybe even life on Earth, he said.