Comets: Soft shell, hard core?
Comet Churyumov-Gerasimenko poses new riddles: Surface material measurements performed by the «Philae» landing module indicate that the near surface material might have changed since its formation. Up to now, many researchers had assumed that it has remained in virtually the same state since its formation about 4.5 billion years ago. The results of the study, in which researchers from the University of Bern were also involved, have been published in «Science» magazine.