Today’s Mars may be a dry and barren wasteland, but millions of years ago, so much water flowed on the red planet’s surface that entire landscapes were shaped by it.

Scientists have known for years that the erosion from huge ancient rivers has created breathtaking valleys and lakes across the surface of the planet.

But, according to a new study, the planet also witnessed wild floods from overflowing lakes, which created vast chasms on the planet’s surface, dumping millions of tons of sediment and drastically altering the planet’s surface.

Unlike on Earth, these changes happened within a matter of weeks and were a much more common occurrence than previously thought.

The study published in the journal Nature, by researchers from the University of Texas, finally answers the mystery of the Martian craters, that had puzzled astronomers for decades.

On Earth, tectonic activity and soil erosion tend to erase much of the impact craters, on the other hand, a lack of tectonic activity on Mars meant the planet is riddled with craters.

When the red planet was still wet, this meant creates filled with water was a common occurrence. When those “crater lakes” were full, the walls would breach causing devasting floods and altering the surrounding landscapes. Prior research has shown that floodwater from these breached craters created deep valleys into nearby landscapes.

“There have been extensive efforts to understand the environmental conditions and formative mechanisms associated with valley network incision, with past global studies primarily proposing formation by surface runoff, groundwater discharge at the heads of valleys, and subglacial drainage from large ice sheets,” said Timothy Goudge, lead author of the study.

Researchers say the findings show that the floodwater from these crater lakes was crucial to the formation of Mar’s ancient river valleys. The floods were found to be responsible for the rapid erosion of up to 24 percent of early river valleys on the planet’s surface.

Cover Image: NASA/GSFC/ JPL ASU