Dusty snow on Mars may soften just under the floor
Dust gets everywhere on Mars, including on ice that was deposited during one of Mars’ earlier ice ages. How this dust affects the ice is still being discussed. In addition to this debate, a recent paper by researchers at Arizona State University and the University of Washington created a map between the dust content of a glacier and the brightness of its ice.
As with many climate-related interactions, the seemingly simple interface between ice and dust is much more complicated than it appears. The team used images from the Phoenix Mars Lander and the Mars Reconnaissance Orbiter to build a model that would predict how bright snow and ice would be here on Earth. Then they flipped that approach to gauge how the dust on Mars affects the brightness of the ice deposits on the planet.
UT video on in situ resource use on Mars.
It turns out that much of the ice on Mars is covered in dust, and the color of that dust makes a huge difference to the ice it covers. Darker dust stems would attract more heat, making the ice covering them more likely to melt. Alternatively, ice that is not covered by dust is reflective, making it less likely to melt in the much weaker Martian sun.
When ice melts due to increased solar radiation, the dust piled on it also reduces the likelihood that the resulting water will evaporate into the Martian atmosphere. The Martian dust itself could therefore play an important role in any hydrological cycle on Mars.
Further analysis of the dust-covered Phoenix snow found. With the help of brightness measurements (albedo), the scientists were able to differentiate between ice and dust.
Credit – Blaney et al
So far, this is just a theory, backed by some preliminary data collected from orbital satellites and a lander. To gain further credibility, this theory must withstand further study of ice samples that will be collected from the surface of the planet in the future. Either way, if humanity ever hopes to build a permanent base on Mars, it will be important to understand how all of the complex factors on the Red Planet work together to create its local environment.
ASU – Martian snow is dusty, could potentially melt, new study shows
AGU – Spectral Albedo of Dusty Martian H2O Snow and Ice
First post – RESEARCHERS FIND THAT THE SNOW OF MARS MIXED DUST AND COULD MELT IN WATER
UT – This is the best place for explorers to harvest Marseis
Snow (white segments) covered in dust, which was then scraped off by the Phoenix lander.
Credit – NASA / JPL-Caltech / University of Arizona / Texas A&M