A new study has found that Mars is emerging from an ice age that ended about 400,000 years ago. While scientists have long believed that the planet has undergone several rounds of ice ages in the past, there have been few physical measurements to actually prove the theory. Now, the journal Science has published the first map of the red planet’s ice deposits, along with confirmation of the planet’s icy past.
Just like Earth, Mars undergoes cycles of planetary warming and cooling, but this has more to do with the “tilt” of the planet than anything else. While Earth’s axis is tilted 23.5 degrees and remains relatively stable over time, Mars has an axis that shifts from 10 to 40 degrees. The wobble in Mars’ orbit is due to two factors: one, it doesn’t have a large moon like we do to stabilize it, and two, its proximity to Jupiter allows it to be tugged by the larger planet’s gravity. When the planet is tilted to an extreme degree, its poles receive more sunlight and its equator cools, causing an ice age.
Researchers used NASA’s Mars Reconnaissance Orbiter to gather radar images of the red planet’s ice deposits, allowing them to look for signs of erosion and other hints of how the ice on Mars has formed and redistributed over time. These images confirmed that Mars’ last ice age ended about 400,000 years ago — which, in planetary terms, is not as long as it seems.
This research is exiting because it gives us more hints about what’s on the Martian planetary surface, which could help lay the groundwork for future manned missions. But it also may offer scientists a better glimpse into the science behind climate change on our own planet. While global warming on Earth is due to greenhouse gas emissions, not the wobble of the Earth’s pole, Mars is the most similar planet to our own in the Solar System and could help us better understand the physics behind climate change in an environment without human interference.
Via The Verge
Images via NASA/JPL-Caltech/MSSS