I know it's a minor planet, but that includes a large array of different stuff. Specifically, I am looking at the general chemistry/geology of the object.
656 Beagle is a small (~53 km diameter) asteroid with a 3.15 AU semimajor axis. It's luminosity is very faint, with H = 9.92. Nothing seems to be known about its geologic basis, but it certainly does not possess a measurable atmosphere. See http://occsec.wellington.net.nz/planet/2008/updates/080912_656_19331_u.htm for more information.