Spending More Than 4 Years on Mars Could Kill Us

May 5

Not to be the one to crush all of Elon Musk’s dreams or anything, but I just found out some bad news.

I’ll admit it, I’ve always dreamed of living on Mars. Something about waking up under a dusty pink sky, sipping coffee in low gravity, and being a tiny speck in an alien landscape? Total vibe.

But apparently, I’d need to keep that Martian lease short. Not that I planned on staying there for good in this fantasy of mine or anything, I’m very partial to trees and forests and such.

According to new research though all of us would need to keep our leases short, because spending more than four years on Mars could literally kill a human.

Yeah…turns out, the biggest threat isn’t the lack of oxygen or food or even water, it’s cosmic radiation. And if we ever want to send people to Mars (and bring them back alive), this problem needs solving, fast. Hello, Elon Musk.

Wait, Why Is Mars So Dangerous?

Okay, maybe a silly question, and you’re immediately like, “well that’s a dumb question, Michele, first of all there’s no air.” But come on, Mars seems like it wouldn’t be that bad. I mean, sure, it’s cold and dusty and has no breathable atmosphere even a little bit, but we’ve seen sci-fi movies. We’ll just build domes or underground bases, right? I’m personally partial to domes in case anyone is wondering.

Well, here’s the thing though, Mars has no magnetic field and almost no atmosphere. On Earth, our magnetic field and thick atmosphere protect us from harmful cosmic rays and solar radiation. It’s like living under a giant invisible shield. By the way, if you haven’t taken a moment to appreciate the invisible shield we have yet today, now’s the time.

Mars, though? Mars is more like living in a house with no roof. Every day, high-energy particles from the sun and deep space rain down on the planet’s surface. And while a quick visit wouldn’t fry you, long-term exposure builds up in your body in ways that aren’t great. (Understatement of the century, yes, I will accept my award any day now.)

The 4-Year Limit: How Did They Figure That Out?

This new study (led by scientists from UCLA, MIT, and other top institutions in 2021-2022) basically asked: “How long could humans safely stay on Mars before radiation becomes life-threatening?”

Their answer was depressingly about four years. After that, the risk of cancer and other radiation-related health issues apparently skyrockets.

It’s not like at four years and one day you drop dead. It’s more like your cumulative exposure reaches a level that dramatically increases long-term health risks.

And this isn’t just “a little sunburn.” We’re talking about radiation that damages DNA, increases cancer risk, and affects the nervous system. Prolonged exposure could even increase the risk of degenerative diseases or super fun for us, a dash of cognitive decline.

Not exactly the retirement plan I imagined for my Martian farmhouse. Guess I’ll just have to keep working on Blockchain Botany to grow my imaginary plants on Mars.

Why Can’t We Just Build Better Shields?

Okay, great question Michele. The obvious answer would be: “Just build thicker walls!” But shielding against cosmic radiation isn’t as simple as my mind seems to want it to be.

Radiation doesn’t just politely stop at a thicker wall. Because normal radiation wasn’t bad enough, some types of high-energy particles can actually create some fun secondary radiation when they hit shielding materials (ie metals), producing a wonderful cascade of additional particles inside your habitat. It’s like plugging one leak and accidentally making three more.

The ideal solution seems to involve a combination of materials, possibly even using Martian soil (regolith) to build thick protective layers. Some scientists have even proposed living underground or inside lava tubes already carved by ancient volcanic activity. I guess the underground idea has more merit than those domes I was voting for. Damn.

But even with that fancy shielding, you’re only reducing the exposure, not eliminating it completely. And every extra day on the surface increases that risk. Boo.

Why Is This a Big Deal for Space Missions?

We’ve always known radiation was a problem for deep space travel, even astronauts aboard the International Space Station (protected by Earth's magnetic field) get higher radiation doses than we do on the ground.

But Mars missions have been the ultimate goal for NASA, SpaceX, and a ton of other space agencies. And until now, timelines for a crewed missions to Mars have ranged from a few months to permanent colonies.

This research puts a hard clock on the dream of living there long-term, sadly. If we can’t figure out better shielding or medical interventions, humans might be limited to short stays on Mars, which would be no more than four years total.

That’s enough time for a mission, but probably not enough for a colony.

(Although, knowing Elon Musk, I’m sure he’s already tweeting solutions while we speak.)

What Does This Mean for Colonizing Mars?

So, realistically, colonizing Mars won’t be as simple as just building houses and greenhouses like we did in my mind.
Radiation is actually a fundamental problem baked into Mars itself.

If we want to stay longer than four years, we’ll need much better shielding materials that don’t cause a whole bunch of other issues, some kind of underground habitats to help reduce the radiation effects, and some biological or medical ways to repair radiation damage.

If we can’t figure out those things, Mars might only be safe for short-term missions, not for the “new home for humanity” we’ve imagined.

And if you’re wondering how come all our robots we’ve sent are fine, fun fact: robots don’t get cancer.

We’ve sent rovers like Curiosity and Perseverance, and they’re thriving (as much as robots can thrive), but human bodies are way more fragile than metal and circuits. Well, for now anyway.

A robot’s circuit board doesn’t care about a blast of solar particles. Your DNA definitely cares, however.

This might be a big part of the reason why robotic missions will always be easier and cheaper. But let’s be real for a moment, no rover selfie can replace the wonder of a human standing on Mars for the first time.

What About Mars Suits?

Another thought I had and was totally destroyed by the internet: spacesuits apparently offer some radiation shielding, but they’re not designed to block the most dangerous high-energy cosmic rays yet. Even the best suits won’t protect you enough for long-term surface work.

Seems like they’re great for the first five minutes but not for five years. That’s the situation here.

Any protective suit or structure would need to be a lot more advanced than what we currently use in space. We’re talking about engineering materials that don’t even exist yet, or haven’t been tested in deep space environments. Yikes.

Here’s the thing, it’s still worth going so I hope I didn’t convince you to give up on your dreams of going to Mars one day.

Every great leap in any exploration has risks. Early sailors faced unknown diseases and uncharted waters, arctic explorers braved frostbite and starvation, and really, Mars will be no different.

This research doesn’t say “we can’t go,” it just says, “we need better prep so we don’t fry some people.”

Also, we’ve already overcome impossible challenges before. Think about it: we put humans on the Moon using computers less powerful than a basic calculator. If we could figure that out, solving the radiation challenge feels like a matter of time.

Even with a four-year limit, Mars remains one of the most exciting frontiers in human history. And maybe, that ticking clock is exactly the challenge we need to drive innovation.

Besides, four years is still longer than most people spend in college, which is plenty of time to explore, research, and stand under that alien sky.

I don’t know about you, but I’d still take the chance. Radiation and all.

Want to Learn More About Space Weirdness?

If you’re as fascinated by space as I am, you’ll love my deep dive on NASA’s “spider web” discovery in deep space. Or check out my latest post on whether black holes might actually be tunnels to white holes.

Because honestly? The universe keeps getting weirder, and I’m so here for it.