Mars' Moon Phobos has been analyzed as being one-third hollow according to European Space Agency reports, which has triggered some wild and utterly fascinating rumors and speculation that we've featured below.

From "The Phobos Blog" -- published on March 25th: General , Science 25 March, 2010 17:21

Radio science result from 2008 Phobos Flyby now accepted for publication:

We report independent results from two subgroups of the Mars Express Radio Science (MaRS) team who independently analyzed Mars Express (MEX) radio tracking data for the purpose of determining consistently the gravitational attraction of the moon Phobos on the MEX spacecraft, and hence the mass of Phobos. We conclude that the interior of Phobos likely contains large voids. When applied to various hypotheses bearing on the origin of Phobos, these results are inconsistent with the proposition that Phobos is a captured asteroid.

Rest of post: [link to www.dailygalaxy.com]