June 15, 2012 at 7:33 PM ET
The mousy shape comes from three overlapping craters in Mercury's southern hemisphere, northwest of a larger crater known as Magritte. The biggest crater in this scene, which serves as Mickey's head, measures about 65 miles (105 kilometers) across.
This picture was taken during Messenger's extended mission, with the aim of collecting imagery when the sun is near the horizon. Such conditions produce long shadows that highlight small-scale surface features. The result is that the Mercury mission's mapmakers get a better sense of the lay of the land.
Messenger became the first spacecraft to orbit Mercury back in March 2011, and the end of its one-year primary mapping mission marked the beginning of a one-year extension. Which means we may be hearing more about Mickey, Magritte and their Mercurial friends for months or years to come.
Where in the Cosmos
The Mickey Mouse Face on Mercury was today's featured image for our "Where in the Cosmos" Facebook contest. It took just a couple of minutes for Leslie Kebschull and Brad Perdew to come up with the locale for the cartoonish craters. Their entries came in just three seconds apart. To reward their quick minds and fingers, I'm sending them a pair of 3-D glasses, courtesy of Microsoft Research's WorldWide Telescope. (Microsoft is a partner in the msnbc.com joint venture.)
To get in on next week's contest, click the "like" button for the Cosmic Log Facebook page. And while you're at it, sign up for the Tech/Science email newsletter, which is sent out Monday through Friday. That's a great way to get your daily dose of Cosmic Log as well as other goodies from msnbc.com's Space and Science sections.
Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.