The Mercury Dual Imaging System (MDIS) has 11 narrow-band spectral filters
covering visible and near-infrared wavelengths (400 to 1050 nm). The
specific colors of the filters were selected to discriminate among common
minerals. Three-color images (480 nm, 560 nm, 630 nm) were combined to
produce an approximation of Mercury’s true color as might be seen by the
human eye (left) (see PIA11364). From this rendition of Mercury it
is obvious that color differences on the surface are slight. Statistical
methods that utilize all 11 filters in the visible and near-infrared
highlight subtle color differences (right) and aid geologists in mapping
regions of different composition. What do the exaggerated colors tell us
about Mercury? The nature of color boundaries, color trends, and
brightness values help MESSENGER geologists understand the discrete
regions (or “units”) on the surface. From the color images alone it is not
possible to determine unambiguously the minerals that comprise the rocks
of each unit. During the brief flybys, MESSENGER’s other instruments
sensitive to composition lack the time needed to build up adequate signal
or gain broad areal coverage, so only MESSENGER’s cameras were able to
acquire comprehensive measurements. Once in obit about Mercury,
MESSENGER’s full suite of instruments will be brought to bear on the newly
discovered color units to unlock their secrets.
Date Acquired: October 6, 2008
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Scale: Mercury’s diameter is 4880 kilometers (3030 miles)
These images are from MESSENGER, a NASA Discovery mission to conduct the
first orbital study of the innermost planet, Mercury. For information
regarding the use of images, see the MESSENGER image use policy.