A dry landslide—not liquid water—is the most likely explanation for at least one of the bright streaks seen recently on Mars

The streaks first made waves in 2006, when scientists reported them in pictures of Martian gullies taken in 2005.

The features had not been in images of the same region from 1999, indicating that something had flowed down those gullies recently.

At the time the researchers figured the most likely candidate was a flash flood—which would have offered proof of liquid water on modern Mars.

The new paper, published this month in the journal Geology, concludes that the shape of at least one of the bright deposits doesn't match the way water would flow.

This doesn't mean that Mars never had water, but it does cast doubt on more recent liquid flowing on the red planet.

The new maps not only provided a more detailed look at the features, they allowed the team to model the flows based on the steepness of the slopes.