Planet Mars has had between six and 20 ice ages in the course of the past 300 to 800 million years, a study published in the Proceedings of the National Academies of Sciences (PNAS) has found.
While the cold surface of the Red Planet may seem barren and dusty, glaciers from millions of years ago lie dormant underneath.
The study, which was conducted by Colgate University planetary geologist and assistant professor of geology Joe Levy discovered that Mars’ glaciers formed across multiple ice ages.
An ice age occurs when the tilt of a planet’s axis is shifted (known as obliquity). The breakthrough has provided scientists with information on how Mars’ orbit and climate have been transformed.
“This paper is the first geological evidence of what Martian orbit and obliquity might have been doing for hundreds of millions of years,” Levy said.
Levy analysed 45 high resolution images of glaciers on the planet’s surface from the Mars Reconnaissance Orbiter satellite.
Levy and 10 Colgate University students counted and measured 60,000 large rocks in the images.
“We did a kind of virtual field work, walking up and down these glaciers and mapping the boulders,” Levy said.
By identifying how the boulders are grouped together, Levy discovered that the rocks were travelling inside the glaciers and were distributed in clear bands of debris. This revealed separate and distinct flows of ice on the surface as Mars’ axis tilted.
Levy said between six and 20 separate ice ages have occurred in the past 300 million to 800 million years on Mars.
“These glaciers are little time capsules, capturing snapshots of what was blowing around in the Martian atmosphere,” Levy said.
“Now we know that we have access to hundreds of millions of years of Martian history without having to drill down deep through the crust – we can just take a hike along the surface.”
Levy and his team are currently mapping the remaining glaciers on Mars’ surface, and will utilise artificial intelligence to identify and count boulders.