Bright reflections beneath Mars’ South Pole’s surface, according to Cornell astronomers, are more likely to be the result of geological layers than liquid water.
In their paper in Nature Astronomy, researchers describe their alternative theory in detail.
According to research associate Dan Lalich, even submerged lakes like Lake Vostok can have reflections that bright on Earth. However, the general consensus was that it should be too cold on Mars for similar lakes to form.
But the bright reflection still exists and needs an explanation, according to Lalich.
Basalt, water ice, carbon dioxide (CO2) ice, and the atmosphere were the four materials used in Lalich’s simulations. Each layer was given a corresponding permittivity, a property of the material that describes how it interacts with electromagnetic radiation passing through it.
Three-layer simulations—two CO2 layers, separated by a layer of dusty ice—produced reflections that were just as bright as the measurements.
We know that CO2 already exists in significant amounts close to the ice cap’s surface, so Lalich said that he used layers of CO2 that were embedded within the water ice. However, in theory, I could have achieved the same results by using rock layers or even particularly dusty water ice. The main argument of this essay is that layer thicknesses and separations matter more than the composition of the basal layers.
The researchers deduced from the models that the thickness of the layers and their spacing have a greater influence on reflection power than their composition. The researchers wrote, “We have shown that bright reflections can be made without liquid water.” They also said that no single simplified stratigraphy in the paper can explain every observation.
Lalich said that due to the stakes involved, it is crucial to identify what on Mars is not liquid water. He remarked, “If there is liquid water, maybe there is life, or maybe we could use it for manned missions to Mars in the future.”
Lalich doesn’t completely rule out the possibility of liquid water, which could have big effects on how old the polar cap is, how Mars heats itself from the inside, and how the climate has changed on Mars in the recent geological past.
According to Lalich, “None of the research we’ve done refutes the possibility that there is liquid water below.” “Simply put, we believe that the interference hypothesis fits the data better. I doubt that anything short of a drill could demonstrate conclusively whether one side of this argument is correct or incorrect. “
