Workshop ROSETTA – OSIRIS at Lutatia

Organisateur :

Date prévue : 1-2 Mars 2011
Date définitive : 2011-03-01

Organisateur : Antonella Barucci (LESIA, tel : 75 39)

From the ground based observations, 21 Lutetia appeared to be a puzzling asteroid different from all the other asteroids. Its nature was uncertain because of contradictory observations, either favoring an M type or a C type asteroid. From polarimetry, Lutetia appeared an atypical object with a surface covered by a fine-grained regolith.

From the amazing images received by OSIRIS imaging system on board of ESA Rosetta spacecraft, Lutetia reveals a complex and morphologically diverse surface, confirming its “weird” character.

Lutetia seems to be a very old object with an irregular shape which is the result of its collisional history. Some smooth younger areas have been also observed. The asteroid lifelong bombardment produced several big craters (tens of kilometers), and many different generation of smaller craters. An apparently tick regolith layer probably covers most of the surface of the asteroid and its presence is revealed by the unique land slide structures along the wall of some craters, most likely generated by impact-induced seismic activity. Sparsely the presence inside some big craters of sparse boulders, apparently dark, indicates a complex impact mechanism.

Moreover images display a great richness of different structures: pits, craters chains, ridges, scarps and wide younger terrains.

The first analysis of the data shows the extreme diversity of Lutetia which does not resemble any other space explored asteroid. The variety of shapes, morphologies, structures, histories provides us with an invaluable patrimony of information.

Goal of the workshop is to discuss the first analyses of the images taken by OSIRIS instruments (taking into account the synergies with the others Rosetta experiments) and summarize the main results concening both the nature of Lutetia and, in général, the knowledge of the asteroid population.