Nearly 11 years after launch and five months into its cosmic road trip with a comet, the European Space Agency's Rosetta orbiter is providing stunning views and raising puzzling questions about its traveling companion: comet 67P/Churyumov-Gerasimenko.

The comet, 67P for short, sports a rubber-duck-shaped nucleus with goosebumps. It's a Baby Huey, sporting a mass of 10 billion metric tons. It displays more variety in the amount and relative abundance of the gases it sheds than researchers expected. And it sports an array of dust and chunks of debris up to six feet across that orbit the nucleus, like bees unwilling to leave the hive's neighborhood.

These are among the observations the Rosetta science team is unveiling in Friday's issue of the journal Science. Rosetta arrived at the comet last August. The observations researchers have described were gathered during the first two months Rosetta and 67P became co-travelers.

The results so far are "tremendous; they are completely changing what we know about comets," says Dennis Bodewits, a researcher at the University of Maryland, College Park,who focuses on behavior and evolution of comets. "Being able to orbit a comet while it is flying close to the sun, we can see things and really figure out how comets work" at an unprecedented level of detail.

Comets, along with asteroids, represent the construction rubble left over from the solar system's planet-building stage some 4.5 billion years ago. Comets in particular are thought to carry some of the most pristine ingredients the young sun and its extended disk of dust and gas had to offer as raw material for planets. Comets also are known to carry organic compounds and are thought to be one type of vehicle that delivered water and organic chemicals to Earth chemicals that could serve as building blocks for more-complex molecules underpinning organic life.

Comet 67P is providing the most rigorous test yet for ideas about how comets form and evolve as they make their periodic pilgrimages toward the sun and back.

Using Rosetta's OSIRIS cameras one for detailed close-ups of the surface and one for wider views the mission's science team has uncovered an amazing variety of surface features.

On large scales, some portions of the surface appear brittle, with sections hundreds of feet across looking as though they'd collapsed after being undermined. Other regions of the surface appear to be vast rubble piles, while others appear as smooth plains. One region hosts a cliff nearly 3,000 feet tall that rises from the adjoining plain.

Virtually the entire surface is covered in a layer of dark dust. The craft's VIRTIS spectrometer has uncovered an array of molecules with high carbon content in the surface material, but precious little ice. This is unlike other comets similar to 67P members of a class known as Jupiter-family comets with return periods of about 20 years. They get their name from the influence Jupiter's gravity has in shaping their trajectories.

"67P represents a different species in the cometary zoo," writes the VIRTIS team in its contribution to the package of Rosetta results in Science.

Read the rest here:

Rosetta's up-close views of comet: stunning, but puzzling