These dramatic gas geysers that blast material hundreds of feet into the air have been discovered on Mars.
The powerful jets of carbon dioxide erupt from layers of ice at the Martian south pole, spraying the surrounding area with fine dark sand.
They are the explanation for mysterious dark spots, fan-like markings and spider-shaped features on the ice cap, say scientists.
Sunlight warming the ice turns frozen carbon dioxide underground into high-pressure gas which shoots through narrow vents at 100mph.
Dr Phil Christensen, from Arizona State University in Tempe, in the United States, said: "If you were there, you'd be standing on a slab of carbon dioxide ice.
"All around you, roaring jets of carbon dioxide gas are throwing sand and dust a couple of hundred feet into the air."
Pictures were beamed back from a Thermal Emission Imaging System (THEMIS) camera on the Mars Odyssey probe.
The findings were published in the latest edition of the journal Nature.
