Comets: Rosetta results and related science
Imaging Comet 67P/Churyumov-Gerasimenko from Rosetta
Stephen Lowry
University of Kent
The European Space Agency’s Rosetta spacecraft began acquiring spatially-resolved imaging of comet 67P/Churyumov-Gerasimenko using the OSIRIS optical camera system in July 2014. While large-scale concavities were expected based on early telescope observations (Lowry et al. A&A 548, 2012), initial images from the spacecraft revealed an unexpected bilobate configuration, which is most likely the result of two components merging early in its formation history. The Rosetta mission is providing an opportunity to study a suspected ‘contact binary’ up close, especially the interface region between the two lobes. Subsequent images of this region and across the whole illuminated northern portion of the comet have exceeded our most hopeful expectations, and have revealed a striking world with a range of surface features including ‘cliff’ faces and terraces, spherical depressions and deep pits (none of which have so far been attributed to impact events), as well as very smooth features possibly indicating upwelling of subsurface material, and regions that imply the presence of ‘winds’ on the surface. There also appears to be many areas on the comet that reveal subsurface structures that may provide direct insight into the very earliest formation processes that where prevalent in the region of the solar system from which 67P originated. I will present an overview of what we have learned to date about the comet from OSIRIS imaging data, and what may await in coming months as Rosetta approaches perihelion in August 2015.
09:00 - 10:30