DARMSTADT, Germany — Turning what seemed like a science fiction tale into reality, an unmanned probe swung alongside a comet on Wednesday after a 4 billion-mile chase through outer space over the course of a decade.

Europe’s Rosetta probe will orbit and study the giant lump of dust and ice as it hurtles toward the sun and, if all goes according to plan, drop a lander onto the comet in the coming months.

Rosetta turned up as planned for its rendezvous with comet 67P/Churyumov-Gerasimenko somewhere between the orbits of Mars and Jupiter.

The incredible trip, launched on March 2, 2004, marks a milestone in mankind’s effort to understand the mysterious “shooting stars” that periodically flash past Earth, and which have often been viewed with fear and trepidation.

While the moon, Mars and even asteroids have been visited, no spacecraft has yet gotten so close to a comet. Having achieved this feat, Rosetta will go one step further and drop a lander on 67P’s icy surface – a maneuver planned for November.

“You can compare what we’ve done so far to finding a speck of dust in a big city,” said Gerhard Schwehm, who was lead scientist on the Rosetta mission until his recent retirement.

That’s probably an understatement.

To catch their quarry, scientists at the European Space Agency had to overcome a series of hurdles that included a tense hibernation period of 31 months during which the probe was out of contact with ground stations.

Rosetta will now spend several months observing 67P from a safe distance of up to 100 kilometers. This will give scientists time to find a safe place to land Rosetta’s sidekick, Philae.

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, according to those involved with the project.