Composite images taken by MESSENGER in hundreds of different wavelengths of light --from ultaviolet to infrared--show Mercury's mineral composition, age and volcanic vents. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
This color image of an young, elliptical crater on Mercury--with bright rays making a butterfly pattern--indicate a very oblique object struck the planet. Taken on May 1, 2013. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
This photo of Mercury's sunlit horizon. The photo was acquired looking from the shadows toward the sunlit side of the planet on Oct. 2, 2013. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
A map of Mercury's north pole, produced by a composite of images MESSENGER captured in the flyover during this flight path over Mercury's north polar region. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Mercury's Lennon crater, named for Beatle John Lennon, as seen from NASA's MESSENGER spacecraft. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Before its trek to Mercury, MESSENGER snapped this mutli-wavelength photo of Earth to test its instruments, showing extraordinary plant growth in red. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Composite images taken by MESSENGER in hundreds of different wavelengths of light --from ultaviolet to infrared--show Mercury's mineral composition, age and volcanic vents. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Composite images taken by MESSENGER in hundreds of different wavelengths of light --from ultaviolet to infrared--show Mercury's mineral composition, age and volcanic vents. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Composite images taken by MESSENGER in hundreds of different wavelengths of light --from ultaviolet to infrared--show Mercury's mineral composition, age and volcanic vents. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)
Composite images taken by MESSENGER in hundreds of different wavelengths of light --from ultaviolet to infrared--show Mercury's mineral composition, age and volcanic vents. (NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution)