As far as we know, Mars is currently completely lifeless. We do not know if this has always been the case, but we know that modern Mars is a hostile place thanks to freezing temperatures and deadly radiation. If humans ever arrive on the Red Planet, we may be able to change that, and a new study gives an indication of how this could happen.
A New Article Published in Nature Astronomy Researchers Explain how a thin layer of airgel – a highly porous, virtually weightless material – could make vast areas of Mars habitable.
Scientists have imagined in the past how to terraform the planet, and the general consensus is that the surface temperature above freezing point of water must be the first big step. As soon as there is running water on Mars, we could start to really change the environment and maybe even make it more liveable, but that's easier said than done.
Researchers in the latest study considered how airgel might play a role. They designed an experiment to simulate how sunlight falling through an "aerosol shield" could alter the conditions of the underlying surface. They found that a layer of silica airgel only 2 to 3 centimeters thick allows enough light to pass through to allow plants to be used for photosynthesis, but also prevents harmful UV radiation.
On Earth, we are dealing with the greenhouse effect because it drives the surface temperature of our planet to dangerous heights. On Mars, an airgel layer could serve the same purpose. Layers of incredibly light material could raise the temperature over large areas, allowing water to flow and plants to thrive.
At this point, of course, everything is very theoretical. Airgel is real and apparently could be used to solve a bigger problem for future Mars settlers, but producing it on the Red Planet (or bringing it completely from Earth) is hardly worth it at this point dream] Source: Jon Wade