The European Space Agency’s (ESA) Rosetta spacecraft has found enormous sinkholes on the surface of comet 67P, according to a recent survey published on Wednesday in the journal Nature.
“We see jets arising from the fractured areas of the walls inside the pits. These fractures mean that volatiles trapped under the surface can be warmed more easily and subsequently escape into space,” said Jean-Baptiste Vincent from the Max Planck Institute, lead author of the study.
According to the study, Rosetta has identified 18 circular pits in the northern hemisphere of the Comet 67P/Churyumov-Gerasimenko.
Scientists are measuring some of these pits, which stretch from a few tens to a few hundreds of meters in diameter and up to 210 meters in depth.
“These strange, circular pits are just as deep as they are wide,” said astronomer Dennis Bodewits from the University of Maryland and a co-author of the study.
“We propose that they are sinkholes, formed by a surface collapse process very similar to the way sinkholes form here on Earth.”
Researchers think that when carbon dioxide, carbon monoxide and water ices are vaporized beneath the surface, a huge void is formed as the gas escapes from holes in the comet.
“Although we think the collapse that produces a pit is sudden, the cavity in the porous subsurface could have growing over much longer timescales,” said another co-author Sebastien Besse from the ESA’s center in the Netherlands.
None of these 18 sinkholes are located near to the landing point of the recently revived lander Philae.
Rosetta has been monitoring Comet 67P for over a year and ESA has officially extended the mission until September 2016.