Coils hint that volcanoes, not ice, shaped odd red planet region.
Hundreds of large spirals have been discovered on Mars, and scientists think the coiled features are evidence of a type of lava flow never before seen on the red planet.
If so, the spirals would suggest that volcanoes—not ice floes, as other experts believe—shaped an unusual area near the red planet’s equator.
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.