Mooning Mercury (April Fool's Day)
This discovery image provides the first evidence that Mercury has a small natural satellite or moon. Visible as a small bright spot in an image taken yesterday by the Mercury Dual Imaging System (MDIS) Wide Angle Camera (WAC), the moon is approximately 70 meters (230 feet) in diameter and orbits Mercury at a mean distance of 14,300 km (8,890 miles). A proposal to name the moon "Caduceus," after the staff carried by the Roman god Mercury, has been submitted by the MESSENGER team to the International Astronomical Union, the body responsible for assigning names to celestial objects.
Date acquired: March 31, 2012
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington