Ice Mounds Abound in Martian Craters

An analysis of the thickness and the shapes of the ice mounds in Martian craters found that the patterns matched Mars’ axial tilt and precession.

Beth Johnson

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IMAGE: Layered ice in Burroughs crater on Mars, with imagery from THEMIS (left) and HiRISE (right panels). The ice layers here record climate oscillations now linked precisely to changes in Mars’ orbit and tilt, according to a new study in the AGU journal Geophysical Research Letters. CREDIT: Sori et al./Geophysical Research Letters

Researchers recently discovered deposits of layered ice in craters in Mars’ southern hemisphere. These deposits gave the team insights into the past orientation of the planet, which in turn, helps us understand more about Mars’ past climate. And that, of course, can help us figure out just when Mars could have been habitable.

The results of this study were published in Geophysical Research Letters with lead author Michael Sori, who matched the ice layers to the tilt of Mars’ axis. Basically, these ice deposits tell us about the temperature, hydrology, and even planetary dynamics of the red planet, just as similar layers can tell us about the same aspects of Earth. The tilt of a planet and how it orbits the Sun affects the temperature which depends on the amount of sunlight hitting the surface.

So thicker layers mean colder periods. That makes sense, right?

You also have to add in the precession of the planet’s axis, or how much it wobbles in space like a top. That can also affect how much sunlight reaches the surface, and as the precession changes the axial tilt over…

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Beth Johnson

Planetary scientist, podcast host. Communication specialist for SETI Institute and Planetary Science Institute. Buy me a coffee: https://ko-fi.com/planetarypan