Mars’ South Pole Looks Like Swiss Cheese and Now Scientists Know Why
by Jen Sako
Mars has a scarlet-red surface, right? But, bizarrely, the planet’s south pole looks like holey Swiss cheese.
For the past few years, scientists have realized that these Swiss cheese-like formations are actually layers of frozen water and frozen carbon dioxide, deposited over the years. Yet they have not had much luck in uncovering how the formations developed and changed.
A recent study published in the Geophysical Research Letters journal, however, gives us a model from planetary scientist, Peter Buhler, of the Planetary Science Institute in Tucson, Ariz., mapping a 510,000-year climate history of these amazing Swiss cheese formations and how they transformed under Mars’ orbital polar tilts, which he calls an “essential step” for understanding its water cycle.
Buhler said a press release,
“Mars experiences 100,000-year cycles in which its poles vary from tilting more toward or away from the Sun. These variations cause the amount of sunlight shining on each latitude band, and thus the temperature of each band, to cycle, too. Water ice moves from warmer to colder regions during these cycles, driving Mars’ basic long-term global water cycle.”
Buhler uses a numerical model “to simulate the build-up of the layers over time.”
He ran the model, “approximately one billion times,” until he was able to statistically determine which specific configuration of water deposition best matched the Swiss cheese layers that are on the Mars now.
Buhler further explained,
“The water layer thicknesses tell us how much water vapor has been in Mars’ atmosphere and how that water vapor has moved around the globe.
The carbon dioxide layers tells us the history of how much of the atmosphere froze onto the ground, and thus how thick or thin Mars’ atmosphere was in the past.”
Understanding Mars’ climate patterns are critical if humans ever want to colonize there.
Buhler also added,
“The history of Mars’ atmospheric pressure and availability of water are critical information for understanding the basic workings of Mars’ climate and near-surface geologic, chemical, and perhaps even biologic history. Specifically, the results of this work provide a major step forward for deciphering the basic workings of Mars’ water cycle.”