The subtle yet surprisingly varied colors of Mercury are revealed in the latest images from NASAs MESSENGER spacecraft, now in its extended mission and second year in orbit.
The image above, a composite of Wide Angle Camera images acquired in 996, 748 and 433 nanometers for red, green and blue, shows a semi-lit limb of Mercury with the bright rayed crater Debussy visible at left. (The image has been rotated 180 degrees from the original, and color saturation was boosted by 25%.)
Named for the French composer Claude Debussy of Claire de Lune fame, the crater itself is approximately 50 miles (80 km) wide. It was first detected by ground-based radar telescopes in 1969 as a bright spot.
Now, 43 years later, we have a spacecraft in orbit sending back images like this. Amazing.
The various colors seen across Mercury are due to different mineral compositions of the geologic regions. The exact compositions are not yet known, and the current puzzle that researchers are trying to solve with MESSENGER is to figure out what materials make up Mercurys complex, multi-hued surface. That will also give a clue as to whats inside the planet and how it evolved as well as how it is currently evolving today.
The image below is from MESSENGERs Visual and Infrared Spectrograph (VIRS) and shows a map of Mercurys surface, with RGB colors corresponding to different mineralogical compositions.
Younger surface materials that are brighter at visible wavelengths and less affected by space weathering show up in reds, yellows and greens. Materials that may have relatively higher iron contents show up in blue.
These are Mercurys other colors maybe not what we would see with our own eyes, but beautiful nonetheless to planetary scientists!
See the above image on the MESSENGER website here.
Explore further: MESSENGER Returns Images from Oct. 6 Mercury Fly-By