Huge Spirals Found on Mars—Evidence of New Lava Type?
Coils hint that volcanoes, not ice, shaped odd red planet region.
Athabasca Valles is a region of flow channels and valleys covered with terrain plates, structures that show clear evidence of something fracturing and drifting across the planet's surface millions of years ago.
Scientists have been divided, however, as to whether the plates were made by the hardening of a massive lava flow or by icy "rafts"—much like Arctic pack ice—from an ancient inland sea.
(Related: "Lava, Not Water, Made Mars 'Riverbed.'")
Now, high-resolution pictures of Athabasca Valles from NASA's Mars Reconnaissance Orbiter have revealed 269 coils up to a hundred feet (30 meters) wide.
"There are no known mechanisms to naturally produce spiral patterns in ice-rich environments on the scale and frequency observed in our study area," study authors Andrew Ryan and