ESA’s Rosetta space mission has discovered massive sinkholes on the surface of the comet 67P it was studying since August, along with its larger module Philae – and turns out they are large enough to engulf Egypt’s Great Pyramid of Giza! The cavities on comet 67P/Churyumov-Gerasimenko, are huge, spanning some 200 metres in diameter and 180 metres in depth. In comparison, the Great Pyramid is 230 metres across and currently 139 metres tall.
Scientists now believe that the pitted surface of the comet is due to the various sink holes which have formed over its surface. This new information will help researchers understand just how comets are formed.
“Finding the pits was a total surprise,” said space physicist Paul Weissman, with NASA’s Jet Propulsion Laboratory in California.
What exactly is a comet? And what is it normally made up of?
Comets are celestial objects composed normally always of a nucleus of ice and dust and – when approaching the sun – develop a ‘tail’ of gas and dust particles pointing away from the sun.
Comets such as 67P are theorized to be only piles of boulder-sized mini-comets made of rock, organics and ices. Gravity pins them together gently. However, this one appears to be markedly different. It’s also a mystery as to why the pits have started collapsing. Researchers think it may be linked to the heating up of a comet as it draws closer to the sun. Several of 67P’s sinkholes, for examples, are pumping out jets of dust.
“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,” lead researcher Jean-Baptiste Vincent, with the Max Planck Institute for Solar System Research, said in a statement.
Similar circular shapes have been found on the surface of other comets, but those pits were filled in by new material that had collected over the eons. Scientists suspect they are seeing freshly formed pits on 67P, which in August will reach its closest point to the sun in its 6.5-year orbit.
None of the 18 pits found on the surface of 67P are located near where Europe’s Philae lander settled in November. Scientists are attempting to re-establish a steady communications link between the newly revived Philae and Rosetta so the lander can resume science operations.
The European Space Agency last week extended Rosetta’s mission, which was due to end in December, to September 2016.
Rosetta is a robotic space probe built and launched by the European Space Agency. Along with Philae, its lander module, Rosetta is performing a detailed study of comet 67P/Churyumov–Gerasimenko (67P).
On 12 November 2014, the mission performed the first successful landing on a comet and returned data from the surface.