Images of Asteroid 21 Lutetia: A Remnant Planetesimal from the Early Solar System

• Published in: Science
• Main Authors: Sierks, Holger, Rodrigo Montero, Rafael, León, Julia María de, Lara, Lucas, López-Moreno, José Juan, Sabolo, Walter
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science 2011
• Subjects: Asteroid 21 Lutetia; North Pole
• Online Access: http://hdl.handle.net/10261/41929; https://doi.org/10.1126/science.1207325

Holger Sierks et al. Images obtained by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras onboard the Rosetta spacecraft reveal that asteroid 21 Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4 ± 0.3 grams per cubic centimeter. The north pole region is covered by a thick layer of regolith, which is seen to flow in major landslides associated with albedo variation. Its geologically complex surface, ancient surface age, and high density suggest that Lutetia is most likely a primordial planetesimal. This contrasts with smaller asteroids visited by previous spacecraft, which are probably shattered bodies, fragments of larger parents, or reaccumulated rubble piles Peer reviewed