PIA14465: An Angular Albedo Arc


An Angular Albedo Arc

Caption:

A distinct albedo difference is visible in this image, separating lighter, smoother ground in the north from darker, older terrain in the south. This contrast is likely indicative of a compositional difference between the two terrains. Although at first glance this feature seems angular, the albedo change most likely marks the edge of an extremely degraded impact basin.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Date acquired: June 21, 2011
Image Mission Elapsed Time (MET): 217183900
Image ID: 409241
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 30.53°
Center Longitude: 226.2° E
Resolution: 343 meters/pixel
Scale: The diagonal length of this image is about 500 km (310 mi) across.
Incidence Angle: 54.3°
Emission Angle: 0.3°
Phase Angle: 54.1°

Background Info:

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. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing.

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
System
Target Type Planet
Mission MESSENGER
Instrument Host MESSENGER
Host Type Orbiter
Instrument Mercury Dual Imaging System (MDIS)
Detector Wide Angle Camera (WAC)
Extra Keywords Grayscale, Impact, Map, Radio, Shadow
Acquisition Date
Release Date 2011-07-18
Date in Caption 2011-06-21
Image Credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Source photojournal.jpl.nasa.gov/catalog/PIA14465
Identifier PIA14465