Humanity is gaining a deeper picture of where to set up shop on Mars.
NASA plans to send crewed missions to Mars early in the 2030s, intending to build a Red Planet exploration outpost in the very distant future. If such a base is to be viable in the long run, its inhabitants must live off the ground and, to the maximum practicable, utilize local capital, agency officials have said.
Water ice, which will not only help keep Mars explorers alive but also promote their trips back to Earth, is the most significant of those commodities. (The main components of rocket fuel, water can be broken into its constituent hydrogen and oxygen.) Setting up a base close to access to water often makes scientific sense, since it is probable that traces of Mars's existence could be located in or near those locations if it ever were.
In the Martian mid-latitudes, which have plenty of water ice and ample heating and sunlight to make operations viable, this base would likely be established. The poles are very icy, but also cold and dark; by Martian standards, the equatorial regions are warm and light, but also comparatively dry. NASA officials also said the mid-latitude terrain often appears to be at low elevations, making it possible for heavy human-class landers to touch down. (Given that Mars' air is just 1% as dense as Earth's, it is beneficial to have a more spacecraft-slowing atmosphere to plummet through).
On Mars, secret ice
Under the planet's prominent red dirt, Mars' mid-latitude ice is buried. But, thanks to a project called Subsurface Water Ice Mapping (SWIM), which is led by the Planetary Science Institute in Tucson, Arizona, and managed by NASA's Jet Propulsion Laboratory (JPL) in Southern California, NASA and its exploration partners are now getting a better idea of where its most accessible pockets are.
"Ultimately, NASA tasked the SWIM project with figuring out how close to the equator you can go to find subsurface ice," Sydney Do, JPL's Mars Water Mapping Project chief, said in a NASA statement. "Imagine we’ve drawn a squiggly line across Mars representing that ice boundary. This data allows us to draw that line with a finer pen instead of a thick marker and to focus on parts of that line that are closest to the equator."
In a paper published online on Monday (Feb. 8) in the journal Nature Astronomy, the SWIM team has just announced its first findings. And from a crewed exploration point of view, these findings are promising, showing that wide swaths of mid-latitudes exhibit signs of ice.
A Martian resource of critical value
The new research does not flag particular areas, team members emphasized, for potential crew touchdowns. But if everything goes according to schedule, it does act as a resource for the people who are going to make those decisions down the line.
In a separate quote, study lead author Gareth Morgan, a senior scientist at the Planetary Science Institute, said: "Of course, safely delivering humans to Mars and ensuring their survival requires many other considerations beyond in situ utilization of water resources, including landing-site safety and solar and thermal specifications".
It is outside the reach of the SWIM project to identify those site criteria and would be premature, provided that all human Mars mission proposals are still in the conceptual stage," Morgan added. "We have a hemispheric ice distribution perspective to support initial landing-site studies and enable the group to investigate the variety of Martian terrains hosting ice.
In the coming years, the ice picture may clear up considerably, especially if a NASA orbiter named Mars Ice Mapper gets off the ground. NASA is negotiating the idea of the Mars Ice Mapper with Japan, Canada, and Italy's space agencies, who could come on board as partners. The mission may be launched by the agency as early as 2026.