PIA11389: A Patch of Black


A Patch of Black

Caption:

Update : This crater containing interesting dark material was given the name Hemingway in July 2009 .

The crater in the lower right-hand corner of this image has a patch of very dark material located near its center. The region of this image has been seen only with the Sun high overhead in the sky. Such lighting conditions are good for recognizing color differences of rocks but not well suited for ascertaining the topography of surface features from shadows. The shape of the surface in this area is difficult to resolve given the lighting angle, but the dark patch is not in shadow. Dark surfaces have also been seen on other regions of Mercury, including this dark halo imaged during the second Mercury flyby ( PIA11357 ) and near such named craters as Nawahi , Atget , and Basho seen during MESSENGER's first Mercury encounter. The example here is particularly striking, however, and from this NAC image the material may appear even darker than in other example areas. The dark color is likely due to rocks that have a different mineralogical composition from that of the surrounding surface. Understanding why these patches of dark rocks are found on Mercury's surface is a question of interest to the MESSENGER Science Team. The right edge of the image here aligns with this previously released NAC image (see PIA11763 ), where other dark surface material, as well as patches of light-colored rocks, can be seen.

Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131771988
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 260 meters/pixel (0.16 miles/pixel)
Scale: This image is about 270 kilometers (170 miles) across
Spacecraft Altitude: 10,100 kilometers (6,300 miles)

Background Info:

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 .

Cataloging Keywords:

Name Value Additional Values
Target Mercury Sun
System Mercury
Target Type Planet Sun
Mission MESSENGER
Instrument Host MESSENGER
Host Type Orbiter
Instrument Mercury Dual Imaging System (MDIS)
Detector
Extra Keywords Crater, Grayscale, Shadow
Acquisition Date
Release Date 2009-01-27
Date in Caption 2008-10-06
Image Credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Source photojournal.jpl.nasa.gov/catalog/PIA11389
Identifier PIA11389