Comet 67P May Break in Two to Expose Fluffy Insides

Is 67P-Churyumov/Gerasimenko the comet-ary equivalent of a candy bar? That’s the conclusion one might draw after reading the latest findings from scientists studying images from the Rosetta probe that show the comet has a crack in its neck and its interior is mostly fluffy layers of dust and ice.

The new photographs and studies were released this week in a special comet issue (sorry - no 67P in a swimsuit on the cover) of the journal Science.

The crack around the duck-shaped comet’s neck is puzzling and worrisome, at least to Comet 67P. Spotted with the Rosetta’s Osiris camera, it’s up to a meter wide and runs for hundreds of meters around the 1 kilometer circumference of the neck. Scientists still aren’t sure if 67P was formed by the joining of two comets or if its shape is due to erosion. They’re also not sure if, as it gets closer to the sun, the crack will get wider or close up.

If it does break apart, it would expose what the scientists have determined is a fluffy interior. Measurements taken by Rosetta’s instruments show that the comet’s mass is 10 tons but its density is only .5 gram per cubic centimeter or half that of water and it has a porosity of between 70 to 80%. This is due to its gravity which is 100,000 times weaker than Earth's and can barely hold on to the layers of dust and ice it's made of.

Adding to 67P’s candy bar looks, the photos also show cylindrical pits on the surface measuring up to 200 meters wide and having giant bumps on the interior walls that could have been formed by gas bubbles or by impacts from micrometeorites.

Let’s hope everything holds together until August 13, which is when comet will be nearest to the Sun and Rosetta will be sent through the gases and clouds of dust coming from the surface. In the meantime, if Comet 67P really WAS a candy bar, what kind do you think it would be?