The innermost planet in our solar system, Mercury has been something of a mystery. Its proximity to the Sun made getting a close look at the planet tricky, but now NASA has released a new video from the MESSENGER probe that shows us a detailed view of Mercury’s surface.
Earlier this year, NASA had released a single false-color image of Mercury’s surface, and this video expands on that. The many images taken by MESSENGER provide the first close-up look at the planet since the single Mariner flyby back in 1975. MESSENGER stands for “MErcury Surface, Space ENvironment, GEochemistry, and Ranging,” proving that budget cutbacks clearly haven’t hit NASA’s Department of Acronyms.
Thanks to the NASA probe, astronomers are getting a much better look at Mercury’s geology than they have had before. The probe has already taken more than 80,000 images of Mercury, and NASA plans to take 80,000 more before it’s through. Those images were spliced together to make the above video, which color-codes Mercury’s features to denote composition. The MESSENGER website explains:
This view captures both compositional differences and differences in how long materials have been exposed at Mercury’s surface. Young crater rays, arrayed radially around fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury’s crust known as the “low-reflectance material,” thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The large circular area near the top center is the Caloris impact basin, whose interior is filled with smooth, somewhat younger volcanic plains. Small orangish spots are materials deposited by explosive volcanic eruptions.
Launched on August 3, 2004, MESSENGER is the first space vehicle to orbit Mercury. It successfully entered orbit around the innermost planet on March 18, 2011, after using flybys of Earth, Venus, and Mercury itself to decelerate and thus save on fuel.