PIA04052: Defrosting North Polar Dunes


Defrosting North Polar Dunes

Caption:

MGS MOC Release No. MOC2-323, 12 December 2002

Each spring as the sun comes up over the polar regions, the seasonal frosts that have accumulated there during winter begin to sublime away. Dunes are among the first features to show spots and streaks resulting from the defrosting process. Unknown is whether the dark spots and streaks are sand (from the dune) that has been mobilized by wind, or frost that has become disrupted and coarse-grained (coarse grains of ice can look darker than fine grains). This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows north polar dunes near 76.6°N, 255.9°W in early spring. The image, acquired in June 2002, is 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

Cataloging Keywords:

Name Value Additional Values
Target Mars
System
Target Type Planet
Mission Mars Global Surveyor (MGS)
Instrument Host Mars Global Surveyor
Host Type Orbiter
Instrument Mars Orbiter Camera (MOC)
Detector
Extra Keywords Atmosphere, Dune, Grayscale, Storm
Acquisition Date
Release Date 2002-12-17
Date in Caption 2002-12-12
Image Credit NASA/JPL/MSSS
Source photojournal.jpl.nasa.gov/catalog/PIA04052
Identifier PIA04052