Craters Munch, Sander and Poe

The top image is a MASCS VIRS interpolated color composite of craters Munch and Sander (center), with Poe toward the east. These craters are in the north of Caloris basin. The center image is a MASCS color composite showing individual spectral footprints. The bottom image is a monochrome MDIS mosaic of the same area. The three crater rims are blue, indicating low reflectance. Sander's floor is yellow, however, which is high reflectance and indicative of fresh 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 areas where footprints are sparse (separated by tens of km), observations are interpolated for complete coverage of the surface. This is particularly true in the northern hemisphere, where Caloris is located. In the MDIS mosaic, some brightness variations are due to tiling of images taken at different illuminations.

Date Created: June 16, 2014
Instruments: 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
Center Latitude: 42.5°
Center Longitude: 154.5° E
Resolution: 1 km/pixel
Scale: Sander crater (center) is about 50 km (31 mi.) in diameter.

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington