Stunning new images of Mercury have been produced by combining data from the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) instrument and the Mercury Dual Imaging System (MDIS) aboard NASA’s MESSENGER spacecraft. These colors are not what the planet would look like to the human eye, but rather the colors that enhance the chemical, mineralogical, and physical differences between the rocks on the surface of the planet.
MASCS/MDIS color mosaics of Mercury. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington.
The MESSENGER spacecraft was launched on August 3, 2004, and was inserted into orbit about Mercury on March 18, 2011. Since then, it has acquired over 250,000 images and extensive other data sets.
To probe the mineralogy of the surface of Mercury, MESSENGER’s MASCS instrument collected hundreds of different wavelengths of light, ranging from the ultraviolet through the near-infrared.
These spectra have been visualized by mapping different wavelengths or combinations of wavelengths into red, green, and blue, so the human eye can distinguish them.
To accentuate the geological context of the spectral measurements, the MASCS data have been overlain on the monochrome mosaic from the MESSENGER’s MDIS.
MESSENGER is only the second spacecraft sent to Mercury. Mariner 10 flew past it three times in 1974 and 1975 and gathered detailed data on less than half the surface.
Now, after MESSENGER has logged more than ten years in flight, the spacecraft and science instruments remain remarkably healthy, but the propulsion system is running on fumes.
The force of solar gravity continues to perturb the spacecraft orbit in a manner that drives the probe downward toward the planet’s surface with each closest approach, and the tanks of propellant – needed to boost the spacecraft to higher altitudes – are running dry.
According to the mission’s science team, MESSENGER will impact the surface of Mercury near the end of April 2015 (possibly on April 30).