The temperatures range from 50 K (purple) to 550 K (red).
The permanently shadowed craters near Mercury’s north pole have thermal environments that allow water ice to be stable in these craters either at the surface or a few tens of centimeters below the surface.
MESSENGER results have shown that Mercury contracted by as much as 7 km in radius, a number substantially larger than previously believed.
Mercury’s tenuous atmosphere scatters sunlight, and the brightness of the emission is proportional to its content.
So you don’t have to be a fan of blues rock to enjoy a gig by Wooden Paul.
For Mercury, as seen in the first graph, this ratio is similar to that for other terrestrial planets at greater distances from the Sun but significantly higher than that for the Moon, which lost potassium during the giant impact that led to its formation.
Particularly high potassium concentrations were observed by MESSENGER's Gamma-Ray Spectrometer at high northern latitudes, as illustrated in the abundance map on the left side of the animation.
The first frame shows an Earth-based Arecibo radar image in red overlaid on a mosaic of MESSENGER’s Mercury Dual Imaging System images, enabling for the first time the identification of the host craters for all of the radar-bright deposits.
The second frame shows the topography of the region as measured by MESSENGER’s Mercury Laser Altimeter (purple: about 5 km below average surface elevation; red: about 5 km above average surface elevation); illumination models derived from the topography show that the radar-bright deposits are located in regions of permanent shadow.
MESSENGER has provided multiple lines of evidence that Mercury’s polar regions host water ice.