Washington, Oct 5 (ANI): The International Rosetta Mission performed a successful close fly-by at the main-belt asteroid (21) Lutetia on 10 July 2010.
Closest approach occurred at 15:45 UTC at a distance of 3160 km - only 2 kilometres further out than the minimum distance Rosetta had to keep in order to track the asteroid continuously.
Rosetta passed the asteroid with a relative fly-by velocity of 15 km/s, and went through zero phase angle at a distance of 16400 km, 18 minutes before closest approach.
Altogether 17 instruments were switched on during the fly-by, obtaining spatially resolved imaging and spectral observations covering wavelengths from the UV to the radio, as well as in-situ measurements of the asteroid and its direct environment.
The asteroid is heavily cratered. Also a giant bowl-shaped depression stretching across much of the asteroid rotated into view. (21) Lutetia was Rosetta's second and main asteroid target in its 11.5-year mission.
The International Rosetta Mission is one of ESA's Planetary Cornerstone Missions and is on its way to rendezvous with comet 67P/Churyumov-Gerasimenko, go in orbit around its nucleus, and accompany the comet for more than a year while it approaches the inner solar system, goes through perihelion, and moves outbound again.
While travelling to the comet Rosetta has performed two fly-bys at main belt asteroids with the scientific objective of providing a global characterization of these asteroids, including the determination of their dynamic properties, surface morphology and composition.
Images and animations from the Lutetia fly-by:ttp://www.esa.int/esaMI/Rosetta/SEM44DZOFBG_1.html (ANI)