Author/Authors :
Thomas، نويسنده , , P.C. and A’Hearn، نويسنده , , Michael F. and Veverka، نويسنده , , Joseph and Belton، نويسنده , , Michael J.S. and Kissel، نويسنده , , Jochen and Klaasen، نويسنده , , Kenneth P. and McFadden، نويسنده , , Lucy A. and Melosh، نويسنده , , H. Jay and Schultz، نويسنده , , Peter H. and Besse، نويسنده , , Sébastien and Carcich، نويسنده , , Brian T. and Farnham، نويسنده , , Tony L. and، نويسنده ,
Abstract :
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 <40 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 >1%. The shape may be the evolutionary product of insolation, sublimation, and temporary deposition of materials controlled by the object’s complex rotation.
Keywords :
Nucleus , comets , comets , geological processes , geophysics
