U.S. and British scientists have proposed an idea to make the Martian climate livable for humans, using a material that mimics Earth’s atmospheric greenhouse effect, Xinhua reported.
The study published in the journal Nature Astronomy showed that a two to three-centimeter-thick shield of silica aerogel could raise the Martian temperatures underneath permanently above the water’s melting point while blocking hazardous ultraviolet radiation.
American scientists and science fiction writer Carl Sagan suggested in 1971 that vaporizing the northern polar ice caps would increase Martian temperatures, but NASA researchers found in 2018 that the greenhouse gases and water it may produce would only increase the Martian atmospheric pressure to about 7% that of Earth, far from enough to make the chilly planet habitable.
In the new study, researchers from the Harvard University, NASA’s Jet Propulsion Lab, and the University of Edinburgh took a more regional approach, the report said.
“A system for creating small islands of habitability would allow us to transform Mars in a controlled and scalable way,” said Laura Kerber with NASA’s Jet Propulsion Laboratory.
The heat-insulating material silica aerogel is 97% porous, which can greatly slow the conduction of heat. It wouldn’t require large amounts of energy to keep an area warm over long periods of time, according to Kerber.
The researchers demonstrated that a thin layer of this material could increase average temperatures of mid-latitudes on Mars to Earth-like temperatures.
It could be used to build habitation domes or even self-contained biospheres on Mars, maintaining permanent liquid water underneath, according to the study.
The researchers are going to test the material in Mars-like climates on Earth, such as the dry valleys of Antarctica or Chile, the report said.
Should humans ever decide to spread beyond Earth, as the late Stephen Hawking declared we must, then growing food on alien worlds will be a skill that has to be mastered.
But on Mars the conditions are hardly conducive. The planet is frigid and dry and bombarded by radiation, the soil contains potentially toxic chemicals and the wispy atmosphere is low on nitrogen.
Researchers acknowledge there are still significant engineering challenges to overcome.
Based on a climate model produced along with the experiment, it would take lots of aerogel and at least two Mars years (or four Earth years) of warming to produce a permanent region of liquid water underneath.
Although aerogel is several times lighter than air, building structures with roofs made out of the material would require shipping large quantities of it to Mars or somehow manufacturing it there.
Silica aerogel is very fragile and porous; layering it within another translucent material, or combining it with flexible materials, could prevent fracturing.
Doing so could increase air pressure under a structure made with an aerogel roof or shield as well, allowing liquid water to pool more easily on the surface instead of vaporizing in the thin Martian atmosphere.
But the study’s authors noted that developing small habitability zones on Mars is more plausible than attempting to “terraform” the planet, as science-fiction writers have proposed doing in the past.
“Mars is the most habitable planet in our Solar System besides Earth,” said Kerber. “But it remains a hostile world for many kinds of life.”