Rosetta at Lutetia
On 10 July 2010, Rosetta made a close fly-by (3168 km from the target) of asteroid 21 Lutetia. 3D models now show a highly irregular shape ((126 ± 1) × (103 ± 1) × (95 ± 13) km3). The spacecraft passed the asteroid at 14.995 km/s. The phase angle of the approach was 7.7 degrees. The OSIRIS imaging system produced some superb images of the target (see below and Thomas et al., 2012). We are currently working on modeling the impact of the latest event (which contributed most to the structure of the Baetica region).
We have demonstrated that ejecta deposition from the largest impact in the north polar crater cluster matches features observed using Rosetta’s OSIRIS camera. Crater erasure via the seismic shock from the impact was shown to be less significant and inconsistent with observation. The velocity field lines ~50 s after impact exhibit a qualitative correlation with surface lineament orientation (Jutzi et al., 2013), which provides a plausible explanation for these remarkable phenomena on small bodies.
Thomas, N., C. Barbieri, H.U. Keller, P. Lamy, H. Rickman, R. Rodrigo, H. Sierks, K.P. Wenzel, G. Cremonese, L. Jorda, M. Küppers, S. Marchi, F. Marzari, M. Massironi, F. Preusker, F. Scholten, K. Stephan, M.A. Barucci, S. Besse, S. Fornasier, O. Groussin, S.F. Hviid, D. Koschny, E. Kührt, E. Martelleto, R. Moissl, C. Snodgrass, C. Tubiana, and J.-B.Vincent, (2012), The geomorphology of (21) Lutetia: Results from the OSIRIS imaging system onboard ESA’s Rosetta spacecraft, Planetary and Space Science, 66, 96-124, doi:10.1016/j.pss.2011.10.003.
Jutzi, M., N. Thomas, W. Benz, M.R. El Maarry, L. Jorda, E. Kührt, F. Preusker, (2013), The influence of recent major crater impacts on the surrounding surfaces of (21) Lutetia, Icarus, 226, 89-100, doi:10.1016/j.icarus.2013.05.022.