Much of the Rosetta data is under embargo, because the instruments were not paid for by ESA but private organisations like Max Planck Institute. Hence the pauc

Much of the Rosetta data is under embargo, because the instruments were not paid for by ESA but private organisations like Max Planck Institute. Hence the paucity of hard data released to the public; the organisations have first dibs on the data to make their money back through publications and in attracting research funding. As an example: http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta Basically, ESA provide the bus on which the science kit rides. As an EU tax-payer I've raged against this in the past but that's just the way it is. Source: direct question on this matter that I put to an ESA PR at a public lecture about Rosetta.