Scientists are saying that the comet 67P, which is currently being studied by the Rosetta probe of the European Space Agency (ESA), has huge sinkholes in it. According to them, the materials underneath the icy dirt-ball’s surface vaporize in places to form voids which cannot support the comet’s crust anymore.
These ceiling collapses result in formation of cylindrical holes which can be as deep as 100m. The researchers are saying that these pits offer a view of 67P’s inside. Max Planck Institute for Solar System Research’s Jean-Baptiste Vincent informed that the width and depth of the sinkholes are almost similar. The biggest one, according to Vincent, is 200 m deep and 200 m wide.
Vincent feels that it’s good that the pits have such dimensions. This is because it is giving them the chance to check what’s inside the comet for the very first time.
All these observations about the comet 67P have been published in this week’s edition of the journal Nature.
Earth also has sinkholes. They are more common in the landscapes that have easily erodible rock varieties like limestone. Watercourses and rain often eats up the underlying sediments, which results in formation of cavities that finally break to create sinkholes. Experts on the Rosetta probe believe that similar events are taking place on the Comet 67P, which is also often referred to as Churyumov-Gerasimenko.
The probe has identified a total of 18 pits on the 4 km wide object’s northern hemisphere. The scientists are saying that as the Churyumov-Gerasimenko moves in the direction of the sun, it starts heating up, which drives off all the buried volatiles and opens up hollows.
As a result of being an excessively porous structure, the comet might have already had these voids. Scientists are saying that loss of the volatiles has only exacerbated the situation.
In addition, despite 67P’s low-gravity setting, its dusty, rocky crusts don’t possess the ability of supporting their own weight. So, they eventually fall to create big pits. This in turn exposes all the walls of the hollows to sunlight resulting in vaporization of the ice within. Pictures captured by Rosetta are clearly showing spurts of dust and gas coming out from the walls of the pits. The floors, on the other hand, are flat, smooth and dusty.