“The findings demonstrate that only a fraction of valley networks match patterns typical of surface water erosion, which is in marked contrast to the conventional view. Using the geomorphology of Mars’ surface to rigorously reconstruct the character and evolution of the planet in a statistically meaningful way is, frankly, revolutionary.”

Grau Galofre’s theory also helps explain how the valleys would have formed 3.8 billion years ago on a planet that is farther away from the sun than Earth, during a time when the sun was less intense.

“Climate modelling predicts that Mars’ ancient climate was much cooler during the time of valley network formation,” said Grau Galofre. “We tried to put everything together and bring up a hypothesis that hadn't really been considered: that channels and valleys networks can form under ice sheets, as part of the drainage system that forms naturally under an ice sheet when there's water accumulated at the base.”

These environments would also support better survival conditions for possible ancient life on Mars. A sheet of ice would lend more protection and stability of underlying water, as well as provide shelter from solar radiation in the absence of a magnetic field — something Mars once had, but which disappeared billions of years ago.

Though Grau Galofre’s research was focused on Mars, the analytical tools she developed for this work can be applied to uncover more about the early history of our own planet.

“Currently we can reconstruct rigorously the history of global glaciation on Earth going back about a million to 5 million years,” said Jellinek. “This work will enable us to explore the advance and retreat of ice sheets back to at least 35 million years ago — to the beginnings of Antarctica, or earlier — back in time well before the age of our oldest ice cores. These are very elegant analytical tools.”

This article was written by University of British Columbia media relations with contributions from Karin Valentine, marketing and media relations manager, ASU School of Earth and Space Exploration.