#virtis

Icy surprises at #Rosetta’s #comet
▻http://blogs.esa.int/rosetta/2016/11/17/icy-surprises-at-rosettas-comet

This article is mirrored from the main ESA Web Portal. #rosetta’s comet approached its most active period last year, the spacecraft spotted carbon dioxide ice – never before seen on a comet – followed by the emergence of two unusually large patches of #water_ice. The carbon dioxide ice layer covered an area comparable to the size of a football pitch, while the two water ice patches were each larger than an Olympic swimming pool and much larger than any signs of water ice previously spotted at the comet. The three icy layers were all found in the same region, on the comet’s southern hemisphere. A combination of the complex shape of the comet, its elongated path around the Sun and the substantial tilt of its spin, seasons are spread unequally between the two hemispheres of the double-lobed (...)

#Comet_67P #Images #Instruments #Science #activity #co2_ice #colour #osiris #VIRTIS

#Rosetta measures production of #water at comet over two years
▻http://blogs.esa.int/rosetta/2016/09/27/rosetta-measures-production-of-water-at-comet-over-two-years

Over the past two years, #rosetta has kept a close eye on many properties of #Comet_67P/Churyumov-Gerasimenko, tracking how these changed along the comet’s orbit. A very crucial aspect concerns how much water vapour a comet releases into space, and how the water production rate varies at different distances from the Sun. For the first time, Rosetta enabled scientists to monitor this quantity and its evolution in situ over two years. In a new study led by Kenneth C. Hansen of the University of Michigan, in the US, measurements of water production rate based on data from #rosina, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, are compared with water measurements from other Rosetta #Instruments. The combination of all instruments shows an overall increase of the production of (...)

#Ground-based_observations #Science #dust #ground-based_observations #miro #rpc-ica #simulations #VIRTIS

Extremely dark, dry and rich in organics: #VIRTIS view of 67P/C-G
▻http://blogs.esa.int/rosetta/2015/01/23/extremely-dark-dry-and-rich-in-organics-virtis-view-of-67pc-g

Based on the press release of the National Institute for Astrophysics in Italy covering the results of the VIRTIS instrument – the Visible and Infrared Thermal Imaging Spectrometer on #Rosetta – that were published last night in the journal #Science. The results are based on data collected by VIRTIS between August and December 2014. The first surprising result emerging from VIRTIS’s study of #Comet_67P/Churyumov-Gerasimenko is the measurement of its #albedo, or how much sunlight is reflected by the surface of the nucleus. With an albedo of only 6%, about half as much as the Moon’s, 67P/C-G is one of the darkest objects in the Solar System. Such a low reflecting power indicates that the surface of the #comet contains minerals such as, for example, iron sulfides, but also carbon-based (...)

#Instruments #organic_molecules