Comet 67P/Churyumov-Gerasimenko has undergone a series of strenuous events over the last 4.5 billion years old that have led to its current shape. Image credit: C. Matonti et al (2019)
Feeling stressed? You’re not alone. The European Space Agency’s (ESA) Rosetta mission has revealed that geological stress arising from the shape of Comet 67P/Churyumov–Gerasimenko has been a key process in sculpting the comet’s surface and interior following its formation.
Small, icy comets with two distinct lobes seem to be commonplace in the Solar System, with one possible mode of formation a slow collision of two primordial objects in the early stages of formation some 4.5 billion years ago. A new study using data collected by Rosetta during its two years at Comet 67P/C-G has illuminated the mechanisms that contributed to shaping the comet over the following billions of years.
The researchers used stress modelling and three-dimensional analyses of images taken by Rosetta’s high resolution OSIRIS camera to probe the comet’s surface and interior.
“We found networks of faults and fractures penetrating 500 metres underground, and stretching out for hundreds of metres,” says lead author Christophe Matonti of Aix-Marseille University, France. “These geological features were created by shear stress, a mechanical ...