Researchers compared Mars’s valleys with the subglacial channels on Devon Island, Canada, and found striking similarities.
Over the past 40 years, researchers have believed that the valleys of Mars originated from rivers that flowed on the surface of the planet, eroding the soil.
However, new research by the University of British Columbia, Canada, suggests that, unlike previously thought, the planet was initially covered by ice sheets.
The findings were published this week in the journal Nature Geoscience. “Only a fraction of valley networks match patterns typical of surface water erosion, which is in marked contrast to the conventional view,” said co-author Mark Jellinek, a professor in UBC’s department of earth, ocean, and atmospheric sciences.
To conduct the research, lead author Anna Grau Galofre and her team examined more than 10,000 Martian valleys using algorithms to compare them with the subglacial channels on Devon Island, in the Canadian Arctic. That’s how scientists discovered striking similarities.
“Devon Island is one of the best analogues we have for Mars here on Earth–it is a cold, dry, polar desert, and the glaciation is largely cold-based,” said co-author Gordon Osinski, a professor in the Western University, Canada.
This theory also helps explain how the valleys formed 3.8 billion years ago on a planet farther from the Sun than Earth, during a period when the star was less intense.
According to the new theory, channel networks can form under ice sheets, as part of the drainage system that naturally forms under an ice sheet when water is accumulated at the base. It would also mean better survival conditions for possible ancient life on Mars.
Even though the research was focused on Mars, the analytical tools developed by scientists for this study can be applied to discover more about the ancient history of our own planet.
Mark Jellinek said he plans to use these new algorithms to analyze erosions on Earth and find out more about our planet’s early history.
“Currently we can reconstruct rigorously the history of global glaciation on Earth going back about a million to five million years,” Jellinek said. “Anna’s work will enable us to explore the advance and retreat of ice sheets back to at least 35 million years ago.”