Raising crops on Mars is far easier in science fiction than it will

be in real life: The Red Planet is an inhospitable world. Among other

challenges, subzero temperatures mean water can persist on the surface

only as ice, and the planet's atmosphere offers little protection to

plants (or people) from the Sun's radiation.

Of course, NASA has plans to eventually put humans on Mars, using lessons it will learn from its Artemis lunar explorations.

And those humans will need to eat. Being able to produce food on Mars

would help reduce the quantity of supplies consuming valuable space and

fuel on crewed missions to the Red Planet. But figuring out how — and

where — to produce that food, while also being exceedingly careful not

to contaminate Mars with Earth-borne bacteria, are some of the

challenges scientists and engineers face.

In a new paper in Nature Astronomy, researchers propose that a

material called aerogel might help humans one day build greenhouses and

other habitats at Mars' mid-latitudes, where near-surface water ice has

been identified. The study was funded by Harvard University's Faculty of

Arts and Sciences.

Aerogel is a Styrofoam-like solid that is 99% air, making it

extremely light. It’s adept at preventing the transfer of heat as well,

making it an excellent insulator; in fact, it's been used for that

purpose on all of NASA's Mars rovers. Moreover, aerogel is translucent,

allowing visible light to pass through while blocking ultraviolet

light's harmful radiation. Most aerogel is made from silica, the same

material found in glass.

In an experiment conducted by lead author Robin Wordsworth of

Harvard, 2-3 centimeters of silica aerogel allowed light from a lamp

tuned to simulate Martian sunlight to heat the surface beneath it by up

to 150 degrees Fahrenheit (65 degrees Celsius) — enough to raise

temperatures on the Martian surface and melt water ice.

"The study was meant as an initial test of aerogel's potential as a

Martian building material," said second author Laura Kerber, a geologist

at NASA's Jet Propulsion Laboratory in Pasadena, California.

Kerber participated in a 2015 NASA workshop to identify the best

places on Mars to send astronauts. "The ideal place for a Martian

outpost would have plentiful water and moderate temperatures," she said.

"Mars is warmer around the equator, but most of the water ice is

located at higher latitudes. Building with silica aerogel would allow us

to artificially create warm environments where there is already water

ice available."

Broadening the regions on Mars where humans could grow things also

opens up new areas where they could conduct valuable scientific

research, Kerber added.