Multiple Sinkholes Discovered on Comet 67P

Posted on July 7, 2015

Astronomers have discovered the there are a number of sinkholes on the surface of Comet 67P. The comet is being monitored by the ESA's Rosetta spacecraft. There are dust jets emerging from the pits on the surface of the comet which astronomers say likely formed by a sudden collapse of the surface. The image shows one of the pits located in the Seth region of Comet 67P.

The pits were observed using high-resolution images from the OSIRIS camera aboard Rosetta from distances of 10 to 30 kilometers. The pits are estimated to range in size from tens to hundreds of meters in diameter. This means some of the pits are quite large. They extend up to 210 meters below the surface. Dust can be seen streaming from the most active sinkholes.

Jean-Baptiste Vincent from the Max Planck Institute for Solar System Research, lead author of the study, says in a statement, "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."

The scientists say the pits form when the ceiling of a subsurface cavity becomes too thin too support its own weight and collapses. The previously hidden material beneath the surface then sublimates. The researchers say a couple ways these pits could form is through seismic shaking or the sublimation of pockets of ices beneath the surface. The diagram below illustrates the comet pit formation.

A larger version of the pit photograph can be found here. The study of the comet pits was published here in the journal, Nature.

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