This image of Orcus Patera was acquired by ESA's Mars Express orbiter; see press release. Orcus is an elliptical depression near Mars's equator, near the well-known volcanoes of Elysium Mons and Olympus Mons. Its origin is unknown, possibly a volvanic feature, or perhaps a circular impact crater that was later deformed by tectonic forces.
Astronomers used the HARPS radial-velocity instrument (at the European Southern Observatory) to detect five exoplanets orbiting the star HD 10180. Two additional planets are also suspected, but their existence is uncertain due to their weak signal. These five make this exo-planetary system one of the most abundant discovered to date. The five planets are Neptune-class, and they all reside at distances interior to Mar's orbit about the Sun. The above graphic is an artist's rendition of this system. A press release is also available.
