And it could help explain debris flows scientists have spotted on sunlit sections of crater and canyon walls in various locations around the planet.
"Mars has likely had active sand dunes during every geologic era, and some of these eras were warmer and wetter than Mars is today," notes Cynthia Dinwiddie, a researcher with the Southwest Research Institute in Boulder, Colo.
"There is some possibility that equivalent processes are currently occurring on Mars," primarily in dune fields in Mars' equivalent of the Arctic, she writes in an email. Still, "the likelihood is even greater that equivalent processes occurred on ancient Mars."
The dune field in Alaska that Dr. Dinwiddie and Southwest Research Institute colleague Don Hooper study sits on the boundary between boreal forests to the south and Arctic tundra to the north. Known as the Great Kobuk Sand Dune field, the sands were first formed during ice ages that occurred between 300,000 and 130,000 years ago.
Glaciers sculpted the Brooks Range to the north and left the sandy debris in the Kobuk River Valley. There, wind, meltwater, and more-recent ice ages would continue to rework the material to leave some 24 square miles of mobile dunes on the surface and another 250 square miles of sandy soils that don't get around much anymore.