Solar system-wide 'climate change': Rosetta spacecraft sees sinkholes on comet

The European Space Agency's Rosetta spacecraft first began orbiting comet 67P/Churyumov-Gerasimenko in August 2014. Almost immediately, scientists began to wonder about several surprisingly deep, almost perfectly circular pits on the comet's surface. Now, a new study based on close-up imagery taken by Rosetta suggests that these pits are sinkholes, formed when ices beneath the comet's surface sublimate, or turn directly to gas.

The study, which appears in the July 2, 2015 issue of the journal Nature, reveals that the surface of 67P/Churyumov-Gerasimenko is variable and dynamic, undergoing rapid structural changes as it approaches the sun. Far from simple balls of ice and dust, comets have their own life cycles. The latest findings are among the first to show, in detail, how comets change over time.

"These strange, circular pits are just as deep as they are wide. Rosetta can peer right into them," said Dennis Bodewits, an assistant research scientist in astronomy at the University of Maryland who is a co-author on the study. The pits are large, ranging from tens of meters in diameter up to several hundred meters across.

"We propose that they are sinkholes, formed by a surface collapse process very similar to the way sinkholes form here on Earth," ... read more>>>...