Shape, density, and geology of the nucleus of Comet 103P/Hartley 2

P. C. Thomas , Michael F. A'Hearn , Joseph Veverka , Michael J. S. Belton , Jochen Kissel , Kenneth P. Klaasen , Lucy A. Mcfadden , H. Jay Melosh , Peter H. Schultz , Sebastien Besse (1) , Brian T. Carcich , Tony L. Farnham , Olivier Groussin (2) , Brendan Hermalyn , Jian-Yang Li , Don J. Lindler , Carey M. Lisse , Karen Meech , James E. Richardson

1 Department of Astronomy [College Park]
2 LAM - Laboratoire d'Astrophysique de Marseille

Data from the Extrasolar Planet Observation and Deep Impact Extended Investigation (EPOXI) mission show Comet 103P/Hartley 2 is a bi-lobed, elongated, nearly axially symmetric comet 2.33 km in length. Surface features are primarily small mounds \textless40 m across, irregularly-shaped smooth areas on the two lobes, and a smooth but variegated region forming a “waist” between the two lobes. Assuming parts of the comet body approach the shape of an equipotential surface, the mean density of Hartley 2 is modeled to be 200-400 kg m(-3). Such a mean density suggests mass loss per orbit of \textgreater1%. The shape may be the evolutionary product of insolation, sublimation, and temporary deposition of materials controlled by the object's complex rotation. (C) 2012 Elsevier Inc. All rights reserved.

Domaines: Astrophysique [astro-ph]

P. C. Thomas, Michael F. A'Hearn, Joseph Veverka, Michael J. S. Belton, Jochen Kissel, et al.. Shape, density, and geology of the nucleus of Comet 103P/Hartley 2. Icarus, 2013, 222 (2, SI), pp.550--558. ⟨10.1016/j.icarus.2012.05.034⟩. ⟨hal-01439472⟩