Water on Mars: How Future Colonists Will Turn Ice and Dust Into Something You Can Actually Drink

Water is life. It's one of those phrases that gets thrown around so often it starts to feel like a bumper sticker. But when you're talking about Mars, it becomes brutally, literally true. No water, no colony. Full stop.

The good news is that Mars actually has water. Quite a bit of it, in fact. The bad news is that almost none of it is sitting in a convenient lake or river waiting to be scooped up. Getting clean, safe water on Mars is going to require some serious ingenuity — and it's going to require input from scientists, engineers, community advocates, and ordinary people who care about what comes out of the tap.

Let's break it down.

Where Is the Water on Mars?

Mars isn't the dry, dead rock it looks like from a distance. Scientists have confirmed water exists there in several forms:

Polar ice caps. Both the north and south poles of Mars have visible ice caps. The northern cap is mostly water ice; the southern cap is a mix of water ice and frozen CO₂ (dry ice). These are real, confirmed reservoirs of water — enormous ones.

Subsurface ice. Radar data from orbiters like the Mars Reconnaissance Orbiter has shown vast deposits of water ice just beneath the surface at mid-latitudes. In some places, this ice is only a few feet underground. In 2018, the MARSIS radar instrument on the European Space Agency's Mars Express orbiter detected what appeared to be a subglacial liquid water lake about a mile beneath the southern polar ice cap.

Regolith-bound water. Martian soil contains water molecules chemically bound to minerals. Heating the soil can release this water as vapor, which can then be captured and processed.

Atmospheric water vapor. Mars's atmosphere is thin and dry, but it does contain trace amounts of water vapor. Specialized systems could theoretically pull this moisture out of the air, similar to how atmospheric water generators work on Earth.

So the water is there. The challenge is getting it out, cleaning it up, and making sure it's safe to drink — repeatedly, reliably, and for a whole community of people.

The Extraction Problem

The most accessible near-term source for a Mars colony is probably subsurface ice. A colony sited near a known ice deposit could drill down, heat the ice, capture the water vapor, and condense it back into liquid water. NASA and other agencies have been developing concepts for exactly this kind of system — sometimes called ISRU, or In-Situ Resource Utilization.

But extraction is just step one. Raw Martian water is not something you want to drink straight. It's likely to contain:

• Perchlorates, the same toxic compounds that make Martian soil so inhospitable to plant life. The Curiosity rover confirmed perchlorates in Martian soil and water sources.
• Heavy metals leached from Martian rock.
• Dissolved CO₂ and other gases.
• Microbial contamination risks — not from Martian life (as far as we know), but from Earth microbes that might hitchhike on equipment.

Cleaning all of that out requires a multi-stage filtration and purification system. Think reverse osmosis, UV sterilization, and chemical treatment — similar to what municipal water treatment plants do on Earth, but miniaturized, closed-loop, and designed to run with minimal outside input for years at a time.

Lessons From Earth We Can't Afford to Ignore

Here's where this gets personal.

Right now, in the United States, millions of people don't have reliable access to clean water. Flint, Michigan became a national scandal, but it's not unique. Native American reservations across the Southwest have faced water access crises for decades. Rural communities in Appalachia and the Mississippi Delta deal with contaminated wells and aging infrastructure. Colonias along the US-Mexico border often lack running water altogether.

The people who have been fighting for clean water in these communities — the engineers, the activists, the public health workers — have developed knowledge and resilience that is directly applicable to Mars. They know what happens when water systems fail. They know how to monitor water quality with limited resources. They know what it costs when communities are cut out of decisions about their own water supply.

Any honest conversation about making clean water on Mars has to reckon with the fact that we haven't solved this problem on Earth. And the solutions we develop for Mars — affordable, efficient, decentralized water purification technology — should absolutely flow back to the communities that need them most right here at home.

The Technology Being Developed

Some of the most promising Mars water tech is being developed through partnerships between NASA, universities, and private companies:

Forward Osmosis Systems. Originally developed for military field use, these systems can purify highly contaminated water using very little energy. NASA has been adapting them for spacecraft and planetary use.

Electrochemical Perchlorate Removal. Because perchlorates are such a specific and serious problem on Mars, researchers have developed electrochemical processes that can selectively break down perchlorate ions in water. Some of this research has dual-use potential — perchlorate contamination is also a problem in parts of the American Southwest.

Closed-Loop Recycling. The ISS already recycles about 90% of its water — including, yes, urine and sweat — back into drinkable water. On Mars, that efficiency will need to be even higher. The goal is a system where virtually no water is lost, ever.

Atmospheric Water Harvesting. While Mars's atmosphere is thin, new materials called MOFs (metal-organic frameworks) can capture water vapor even in very dry conditions. Research teams at MIT and UC Berkeley have been working on MOF-based water harvesters that could work on Mars — and in dry regions on Earth like the American Southwest.

What This Means for the Rest of Us

You might be reading this in a city where clean water flows out of your tap without a second thought. Or you might be in a community where that's not the case. Either way, the work being done to solve the Mars water problem is connected to your life.

Here's how to engage:

• Follow open-access research from NASA's ISRU projects and university water science programs. Much of it is publicly available and genuinely interesting.
• Support water justice advocacy in your own community and nationally. Organizations like Dig Deep and the US Water Alliance are fighting for universal water access right here at home — and the technology and policy frameworks they're pushing for overlap significantly with what Mars will need.
• Get involved in citizen science. Programs like Globe Observer and various NASA Earth science projects let everyday people contribute to water and climate data that feeds into planetary science research.
• Advocate for open-source water tech. Push back against the idea that life-critical technologies should be proprietary. Water purification that works on Mars should be freely available to communities on Earth that need it.

The Bigger Picture

Making clean water on Mars isn't just an engineering problem. It's a statement about what kind of civilization we want to build out there. Will water be a commodity controlled by whoever owns the drilling equipment? Or will it be treated as a common resource, managed collectively, accessible to everyone in the colony regardless of their role or status?

That question doesn't have a technical answer. It has a political one. And it's a question all of us — not just the people who buy rocket tickets — deserve a voice in answering.

Water is life. On Mars, maybe more than anywhere, that'll be impossible to ignore.