Take two smaller comets and add a cosmic smashup
MPS for OSIRIS Team/Rosetta/ESA, MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
To make one oddly shaped comet, take two smaller comets and squish them together. That probably explains why comet 67P/Churyumov-Gerasimenko looks like a rubber duck, a new study reports.
Since the Rosetta spacecraft’s arrival last August (SN: 9/6/14, p. 8), researchers have debated whether 67P was a comet that lost some weight around its waistline or two comets that got a little too attached to one another. Layers and terraces on cliffs gave away 67P’s coupling. Mismatched layers between the head and body imply that the two lobes formed independently and later fused together, Matteo Massironi, a geologist at the University of Padua in Italy, and colleagues report online September 28 in Nature.
The cliffs provide a peek at what passes for bedrock on a comet, revealing a stack of ice and dust