Deep Impact Observations by OSIRIS Onboard the Rosetta Spacecraft
Keller, Horst Uwe; Hviid, Stubbe F.; Lamy, Philippe; Sierks, Holger; Rodrigo, Rafael; Barbieri, Cesare; Jorda, Laurent; Küppers, Michael; Knollenberg, Jörg; Rickman, Hans; Gutierrez, Pedro J.; Lara, Luisa-Maria
Germany, France, Spain, Italy, Sweden
Abstract
The OSIRIS cameras (optical, spectroscopic, and infrared remote imaging system) onboard the European Space Agency's Rosetta spacecraft observed comet 9P/Tempel 1 for 17 days continuously around the time of NASA's Deep Impact mission. The cyanide-to-water production ratio was slightly enhanced in the impact cloud, compared with that of normal comet activity. Dust particles were flowing outward in the coma at >160 meters per second, accelerated by the gas. The slope of the brightness increase showed a dip about 200 seconds after the impact. Dust Afρ values before and long after the impact confirm the slight decrease of cometary activity. The dust-to-water mass ratio was much larger than 1.