In situ mass spectrometry during the Lutetia flyby
Wurz, P.; Altwegg, K.; Balsiger, H.; Berthelier, J. J.; Rème, H.; Calmonte, U.; Fiethe, B.; Rubin, M.; Mall, U.; De Keyser, J.; Hässig, M.; Jäckel, A.; Fuselier, S.; Hofer, L.; Schläppi, B.
Switzerland, France, Belgium, Germany, United States
Abstract
During the Rosetta flyby at asteroid Lutetia the ROSINA instrument tried to detect a thin exosphere of the asteroid. Although the instrument is sensitive enough to detect even very tenuous gases at a density level of 1 cm-3 the Lutetia exosphere could not be unambiguously detected due to spacecraft outgassing, which was not constant because of the changing solar aspect angle. An upper limit for a water exosphere density at the flyby distance of 3160 km of (3.5±1.0)×103 cm-3 was deduced from the measurements.