Topics Space and the universe

Could humans live on Mars?

Not comfortably, and not yet. Humans could probably survive on Mars only inside sealed, heated, shielded shelters or suits. The air is very thin and is mostly carbon dioxide, so nobody could breathe it. The surface is far colder than most places on Earth, and with little atmosphere and no global magnetic field, radiation is a serious concern. No person has ever set foot there.

What makes the question interesting is that Mars is the least hostile of the other worlds nearby. A Mars day is just a little longer than an Earth day, there is water ice, and robotic rovers have studied the ground for years. But a trip takes many months, supplies are hard to send, and nobody knows how bodies cope with years of low gravity. Whether a lasting settlement is realistic, or what terraforming could ever achieve, is debated.

An episode would walk through the problems one at a time: air, water, food, radiation, the journey, and the human side. bre's hosts are AI, so they can be wrong, and the episode says plainly where the science is unsettled. You can press Talk at any point and ask your own question.

What a bre episode would cover

An outline of the episode bre would make for this question. Every episode is written fresh when you ask, so yours will differ.

  1. What Mars is actually likeA cold, dry, dusty world with a thin atmosphere and about a third of Earth's surface gravity. Its day is close to ours, which helps.
  2. Air, water and foodHow people might get breathable oxygen, use water ice, and grow crops in Martian soil. Some of this has been tested only in small experiments.
  3. Radiation and the thin skyWhy a weak atmosphere offers little protection, and how burying shelters under soil might help.
  4. Getting there and backThe trip takes months, launch windows come around roughly every two years, and every kilogram sent is costly.
  5. What it does to a body and a mindLower gravity, isolation and long delays in talking to Earth. What space station stays can and cannot tell us.
  6. Could Mars ever be made more Earth-like?The idea of terraforming, and why many scientists doubt it is possible with known methods.

How the episode might open

A sample exchange between two of bre’s AI hosts, bre and Cal. Both are AI; this is written by AI, as every bre episode is.

  1. breAI host

    Okay, the question first: could people actually live on Mars? Not visit, not plant a flag. Live there, eat dinner, raise kids.

  2. CalAI host

    Short answer, maybe. Long answer, and this is the part that gets me, it depends on what you mean by live, because you would be living inside a very elaborate sealed box.

  3. breAI host

    A box. Go on. What is outside the box?

  4. CalAI host

    Air you cannot breathe, mostly carbon dioxide and very thin, cold that makes Antarctica look like a beach holiday, and radiation hitting you with hardly any sky to stop it.

  5. breAI host

    And yet people keep wanting to go. Why Mars and not, say, the Moon?

  6. CalAI host

    Mars has water ice and a day about as long as ours. Hold on, how does that actually work for growing food, though? The soil has chemicals we would need to deal with first.

  7. breAI host

    I don't know how well that scales, honestly. We will separate what has been tested from what is just hoped for.

  8. CalAI host

    Good, because the hoped-for list is long, and the money side of it makes my head spin.

Questions people also ask

Can you breathe on Mars?
No. The atmosphere is very thin and is mostly carbon dioxide, with very little oxygen. A person would need a pressurized suit or shelter with its own air supply. Robotic experiments have made small amounts of oxygen from the Martian atmosphere, but that is far from supporting people.
How long does it take to get to Mars?
With current rockets, a one-way trip generally takes several months, roughly half a year or more. The best launch windows come about every two years, when Earth and Mars are well placed. A round trip with a stay would take years.
Has anyone been to Mars?
No human has. Many robotic orbiters, landers and rovers have, and they have taught us a great deal about its rocks, weather and ancient water. Crewed missions have been proposed by space agencies and companies, but none has flown.
Could we make Mars like Earth?
This is called terraforming, and it is debated. Mars may not hold enough easily released gas to build a thick atmosphere, and it lacks a global magnetic field. Many scientists think it is not possible with today's technology, and some doubt it ever will be.

Related topics

More: all 300 topics, space and the universe, or the longer reads on /learn.

bre’s hosts are AI, and every episode is generated, so they can be wrong: check anything that matters. This page outlines what an episode would cover. It is for interest and learning, not medical, financial or legal advice.