As on the Moon, future human settlements on Mars will have to be located near an essential resource: water. But you still have to know where it is.
If we often talk about SpaceX’s Martian projects, let’s remember that NASA also plans to launch a manned mission to the red planet in the 2030s, with the ambition of establishing a first research outpost. With this in mind, future explorers should draw on local resources wherever possible.
The most important of these resources is probably the water ice which will not only be crucial for survival supplies, but will be used for agriculture or even for the production of rocket fuel by dividing it into its constituents hydrogen and oxygen. In other words, water ice will be essential to be able to live there, but also to return to Earth.
Finally, water ice could be studied for purely scientific purposes in order, for example, to probe the possible presence of traces of microbial life.
But then, where to land?
According to NASA, this base will probably have to be built at the level of Martian mid-latitudes. There is ice, but also enough heat and sunlight to operate. The Martian poles are indeed also home to a lot of ice, but they also have the disadvantages of being very cold and very dark.
Mid-latitude terrain also tends to be at low elevations, which is a real plus when landing. Mars is indeed coated with a very fine atmosphere, too fine to allow heavy machinery to brake enough to allow a smooth touch. Also, the more atmospheric thickness there is, the less complicated it will be to land.
If we know that there is ice at the mid-latitudes of the planet, the question we must now ask ourselves is: where exactly is it hiding? A new project called Groundwater ice mapping (SWIM), led by the Planetary Science Institute in Tucson, Arizona, allows us today to see a little more clearly.
A map of Martian ice
To draw up this map, the researchers relied on data collected over the past two decades by three NASA orbiters (Mars Reconnaissance Orbiter, Mars Odyssey and Mars Global Surveyor) using five different remote sensing techniques, including neutron spectroscopy and radar.
“Ultimately, NASA tasked the SWIM project to determine how far from the equator you could travel to find ice underground.“, Summarizes Sydney Do, head of the water mapping project on Mars at JPL. “Imagine we have drawn a wavy line across Mars representing this ice line. This data allows us to draw this line with a thinner pen instead of a thick marker and focus on the parts of that line closest to the equator.“.
The SWIM team has just published its first results on Monday in the journal Nature astronomy. And these data are encouraging. It appears that large strips of land that line the mid-latitudes shelter ice buried at depths ranging from only a few centimeters to a kilometer.
Valuable data for the future
Of course, delivering humans safely to Mars and ensuring their survival requires many other considerations beyond in situ use of water resources. Also, the choice of the future landing site is obviously not yet relevant. Nevertheless, these data can be reviewed and taken into account by decision-makers in due course.
They could also be further refined in the years to come. NASA has in fact joined forces with three space agencies (Italy, Canada, Japan) to work on a mission project called Mars Exploration Ice Mapper. The objective will be to map exploitable ice deposits by the crews of a manned mission. This mission could be launched from 2026.