Could Anyone Live on Mars?

There are two versions of this question, and they have very different answers.

The first version is: does anything live on Mars right now? The honest answer there is "we don't know — and that's exactly what NASA is trying to find out."

The second version is: could humans ever live on Mars? That answer is more concrete: not yet, but maybe within your lifetime.

Let's take both questions in turn.

Is There Life on Mars Already?

Nobody's ever found a Martian. Or a Martian plant. Or a Martian bug. So far, every rover and lander we've sent has come back without proof of life.

But "no proof of life" is not the same as "definitely no life." Mars probably had liquid water on its surface for at least a billion years a long time ago, which is plenty of time for microbes — tiny single-celled creatures — to have appeared. On Earth, microbes were the first form of life, and they showed up almost as soon as the planet had liquid water.

So the search has shifted. NASA isn't really looking for life walking around on Mars today. It's looking for clues — chemical fingerprints — that something used to live there, billions of years ago, when Mars was warmer and wetter.

The Cheyava Falls Discovery (2024)

In July 2024, NASA announced something pretty exciting. The Perseverance rover, working in an ancient lakebed called Jezero Crater, had drilled into a rock the science team named Cheyava Falls.

The rock contained organic compounds — carbon-based molecules that often come from living things — along with strange tiny spots that looked a bit like the chemical signatures microbes leave behind when they break down minerals.

Scientists are being very careful with this. There are non-living explanations for what Perseverance found, and you don't claim "we discovered alien life" without rock-solid proof. The samples are sealed inside Perseverance for now. They'll only get a final answer when the rocks are shipped back to Earth as part of the future Mars Sample Return mission, where labs can study them with much more powerful equipment than a rover can carry.

It's the most promising thing anyone has found on Mars in decades. But promising isn't the same as proven.

Where Is the Water?

Liquid water is the one thing every form of life we know about needs. So tracking water on Mars is a huge part of the search.

Today, most of Mars's water is frozen. Polar ice caps at the top and bottom hold massive amounts of water ice. Just below the surface across most of the planet, there's even more buried ice. NASA's Phoenix lander touched it directly back in 2008.

There's also some liquid water around. In 2018, scientists using ground-penetrating radar from a European spacecraft spotted what looked like a salty lake of liquid water about 1.5 km below the south polar ice. There are also dark streaks called recurring slope lineae that flow down crater walls in summer — likely briny water trickling out of the ground when it warms up enough.

Long ago, there was much more. The riverbeds, deltas, lake floors and shorelines that rovers have photographed all show that 3.5 billion years ago Mars had a hydrologic cycle similar to Earth's. Water flowed, pooled, evaporated, rained down again. That's the Mars where life might have started.

Could Humans Live on Mars?

Right now? No. The list of problems is brutal.

• The air is unbreathable. Mars's atmosphere is 95% carbon dioxide and only 0.16% oxygen.
• The pressure is too low. Without a sealed spacesuit, a person's blood would actually boil from low pressure alone.
• It's freezing cold. The average surface temperature is –63 °C (–81 °F).
• There's no magnetic field. That means radiation from the Sun and from deep space hits the surface much harder than on Earth.
• The dust gets into everything. Mars dust is made of fine, jagged grains that are slightly toxic to breathe.
• Low gravity is a long-term health problem. Astronauts who spend many months at low gravity lose bone density and muscle mass, even with daily exercise.

So nobody's stepping out of a Mars rocket and going for a walk in shorts.

What Would a Mars Base Look Like?

Engineers are seriously working on this. The general plan goes like this:

Sealed habitats. Astronauts would live in pressurized buildings — almost like living inside a giant inflatable balloon, with breathable air piped in. Some designs put the habitats partly underground, or cover them in a thick layer of Mars dirt, to block radiation.

Make oxygen on Mars. Hauling enough oxygen from Earth would be hopelessly expensive. But the Perseverance rover is carrying a tool called MOXIE that has actually done it: turning Mars's carbon dioxide into breathable oxygen. MOXIE is small, but it's proof the chemistry works. Scaled-up versions could make enough oxygen for an entire crew.

Use Martian water. Astronauts would dig up the buried ice, melt it, purify it, and use it for drinking and growing food. Splitting some of it apart with electricity would also produce oxygen and hydrogen fuel for the trip home.

Grow food on site. Greenhouses would grow plants under artificial light, using a mix of Earth soil, recycled water, and whatever could be made from Martian regolith.

When Are Humans Going?

This is changing fast.

NASA is targeting the 2030s, with their first crewed Mars mission coming after they've spent more time on the Moon at the upcoming Artemis bases.

SpaceX wants to go even sooner with its Starship rocket, although the timelines have slipped a few times. Founder Elon Musk has talked about building a city on Mars eventually.

The trip itself takes about 7 to 9 months one way, and astronauts would have to wait on Mars another 18 months for Earth and Mars to line up again before flying home. So the very first crewed Mars mission would last around three years from launch to return. A long time to be away.

The Honest Answer

So could anyone live on Mars? Today, no. Tomorrow, with the right technology and a lot of money, yes — but only inside sealed habitats, with imported air, water from melted ice, and oxygen made from Martian air.

Whether life ever lived on Mars is a different question, and the next decade might finally answer it. The Cheyava Falls samples are sitting in Perseverance right now, waiting to come home. When those rocks reach a lab on Earth, we'll find out if Mars was ever a second living planet.

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