During today's science briefing at ESA's ESOC, Ramy El-Maarry (University of Bern) presented a series of highlights about the landscape of Comet 67P/Churyumov-Gerasimenko.
Over the past two years, Rosetta mapped the entire surface of the comet at high-resolution, resolving very small features and monitoring surface changes with time.
The comet nucleus is indeed very dark (see our 2014 blog post NAVCAM's shades of grey), reflecting only about 4% of the light that hits it. But why is it so dark?
Measurements from both Rosetta and Philae report that most of the surface is dry (with the exception of icy boulders) and covered in organic material, most of which had never been detected on the surface of a comet (on this topic, see previous blog posts: Extremely dark, dry and rich in organics and Science on the surface of a comet).
The surface presents a rich diversity in texture, with the northern hemisphere mostly covered in dust, produced by the comet's activity – for example in the Ma'at and Ash regions.
Philae's multiple landings allowed scientists to observe in details two distinct regions on the comet's surface: the smooth-covered terrains at the first touchdown point, Agilkia, and the hard surface at ...