The seasonal thawing of carbon dioxide ice near Mars’ north pole carves grooves in the red planet’s sand dunes, new research has found.
Researchers using Nasa’s Mars Reconnaissance Orbiter see seasonal changes on far-northern Martian sand dunes caused by warming of a winter blanket of frozen carbon dioxide, Nasa said in a statement.
Earth has no naturally frozen carbon dioxide, though pieces of manufactured carbon-dioxide ice, called “dry ice,” sublime directly from solid to gas on Earth, just as the vast blankets of dry ice do on Mars. A driving factor in the springtime changes where seasonal coverings of dry ice form on Mars is that thawing occurs at the underside of the ice sheet, where it is in contact with dark ground being warmed by early-spring sunshine through translucent ice. The trapped gas builds up pressure and breaks out in various ways. Transient grooves form on dunes when gas trapped under the ice blanket finds an escape point.