The Rosetta spacecraft has discovered massive sinkholes on the comet it is surveilling, and they are big enough to swallow the Great Pyramid of Giza. Scientists say the sinkholes may be caused by collapses of the comet’s external materials, just like ones on Earth. The discoveries on the comet—dubbed the mouthful name of 67P/Churyumov-Gerasimenko—may help scientists understand how comets are formed. The sinkholes were a surprise, and some speculate they may form as the comet gets closer to the sun.
