July 7, 2014
Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) and Mercury Dual Imaging System (MDIS)
VIRS Color Composite Wavelengths:
575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
Waters crater (center) is about 15 km (9.3 mi.) in diameter
The top image is a MASCS
VIRS color composite
of Waters crater
(center) in Mercury's mid latitudes. The bottom image is a monochrome MDIS mosaic of the same area. The central blue area corresponds to both Waters and its impact melt flow
. The encompassing yellow area likely relates to Waters' ejecta blanket
. Blue areas indicate low reflectance, while yellow areas relate to high reflectance and newer material.
The VIRS composite shows hundreds of individual footprints tracks (minimum 100-200 m across and 3-4 km long) taken from different directions and altitudes. In locations where multiple footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map. In the MDIS mosaic, some brightness variations are due to tiling of images taken at different illuminations.
The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation
are unraveling the history and evolution of the Solar System's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
For information regarding the use of MESSENGER images, see the image use policy.