The latest discovery increases the chances of life existing on the planet in the recent past, or even surviving today. That can be scarry at some level. Scientists have identified the gullies inside a crater that appear to be not more than 1.25 million years old.
The theory is that the channels must have been sculpted by surface water from melting ice. There is evidence of water-borne sediments being carried down from high ground and deposited in low-lying alluvial fans. The gully system is in Promethal Terra, an area of cratered highlands south of the Martian equator.
Professor James Head, from Brown University in Rhode Island, USA, was in the team that reported the discovery in the journal Geology. He said: "We think there was recent water on Mars. This is a big step in the direction to proving that."
The best theory for the gullies is melting snow and ice rather than groundwater bubbling up to the surface. This lobe it's probable to be about the same age. The other three lobes were unblemished and therefore had to be younger, said the scientists.
As a final conclusion, experts think the planet was occasionally wet for far longer than was initially believed.