Martian Gullies: An Explosive Discovery

Laboratory experiments have settled a long-standing Martian mystery: the gullies etched across the planet’s dunes owe their existence to explosive movements of dry ice, not flowing water. The results, published in Phys.org, overturn previous assumptions about the Red Planet’s surface and its habitability.

CO₂ Ice in Martian Winters

• Blocks of carbon dioxide ice, known as dry ice, form during Mars’ harsh winters as temperatures plunge to -120°C.

• As sunlight returns, meter-long slabs of CO₂ ice break from dune crests.

The Sublimation Process

• Martian sunlight heats the sand, causing the bottom of the ice to sublimate rapidly—directly transitioning from solid to gas.

• This creates a pressurized gas cushion, "burrowing" and sliding the ice block downhill, carving deep, sinuous gullies.