Surprising Ways Humans Could Survive On Other Planets | Unveiled

The Surprising Ways Humans Could Survive on Other Planets

Sooner or later, the Earth will end. Whether it’s via climate change or as our own sun transforms into a red giant, it’s destined to die eventually. If we’re alive to see that happen, humanity will be faced with a tough decision: where could we call home next?

This is Unveiled and today we’re uncovering the extraordinary ways that humans could survive on other planets.

Earth is special because it’s the only planet that we know for sure can harbour life. A variety of circumstances make this possible; we have liquid water, an atmosphere, a magnetic field and we’re in the solar system’s “Goldilocks Zone” - where it’s not too hot or too cold. It’s perhaps unlikely that there are many other worlds out there which share all of this in common… So if, for any reason, our species ever does find itself jetting off into space, we’d need to find other ways of making other planets suitable for life.

Mars appears the most likely destination for another home, but even it poses complications. It’s thought that there would be more than enough water on the Red Planet, trapped in the ice caps, but it doesn’t have a magnetic field strong enough to protect life from the radiation of outer space; it doesn’t offer the oxygen that so many of Earth’s life forms depend on; and there isn’t an atmosphere of note. Of course, Mars isn’t the only solar system hope for an off-Earth home, with other contenders including distant moons like the Jovian satellite, Europa - which has large amounts of ice and water and is even a contender to already host life below its icy surface. But despite Europa’s encouraging credentials, there are aspects of it that still pose major problems, including issues linked with gravity and, again, radiation.

If we ever hope to live anywhere else, we need solutions. And for Mars, there have been a number of “fixes” put forward. According to a study by Harvard University’s Robin Wordsworth, we may be able to solve the specific challenges of liquid water and building an atmosphere in one satisfying move. By covering the surface of Mars (or parts of it) with raised layers of silica aerogel, an insulator used in buildings on Earth, we could slowly melt away the Martian ice caps. And, as large amounts of water but also carbon dioxide are released, the process could kick-start our efforts to make Mars more liveable - with the CO2 gathering to form a thicker atmosphere. At the same time, the aerogel sheets would shield anything below them from UV radiation, in theory allowing plant life to grow, to introduce oxygen into the atmosphere, as well.

Another idea on “how to melt the ice” comes from Elon Musk. And it’s a little more… dramatic. Musk’s advice is to nuke the planet! By creating controlled and continuous nuclear explosions above the ground, the bombs could act as miniature suns to eventually melt the ice caps - to trigger the same processes as the aerogel approach. While Musk specifically made the proposal when considering ways to terraform Mars, it might just as well work on any planet with large enough amounts of water trapped in ice. Perhaps unsurprisingly, this idea does have its critics… with some arguing that multiple explosions could have the opposite effect than intended, covering the planet in a cloud of debris that would block out the sun, instead. In our bid to survive on another world, we’d have actually plunged it into a nuclear winter... For his detractors, then, Musk’s plans are the last of last resorts! Especially as they could also only add to another of the major challenges facing humans on another planet… exposure to radiation.

When the human body meets the charged particles of space it can cause cancer, damage to the nervous system, and can even alter the genetic code in our DNA. As such, NASA lists radiation as one of the most pressing concerns for any proposed deep space missions of the future. The standard methods to try to manage the risk of radiation usually centre on the materials used to make spaceships and spacesuits. But, one less conventional idea on how we could avoid rad exposure is by living in underground lava tubes. Underground lava tubes, as the name implies, form out of hardened lava on certain planets. They’re sweeping tunnels, they’re usually pitch black and they can be as deep as the Grand Canyon. But, if space-faring humans could find a way of getting inside them, they also block out radiation. In this way, they’re arguably a safer, more cost-effective and certainly more “ready-made” alternative to proposals that astronauts on another world would need to build their own rad-proof pods on the surface. Living in lava tubes would be a challenge - particularly when it comes to generating power and finding space - but another positive of underground living would be that we’d avoid all of the dust storms, ice storms and any other, often unknown forces of nature which regularly pummel the surfaces of other worlds.

If living underground doesn’t work, we might instead turn to the sky. Venus seems an unlikely contender for human habitation thanks to its scorching temperatures and it having an atmosphere 90-times thicker than Earth’s, but it could be possible to live there with the right techniques and technology. In general, the task facing us would be the opposite of what we’d have on somewhere like Mars, as we’d need to slow down - or flat out avoid - the greenhouse effect rather than speed it up.

One especially ambitious idea is to build a colony in Venus’ clouds. First proposed by NASA scientist Geoffrey Landis, the idea rests on the fact that higher up in Venus’ atmosphere (about 50 kilometres above the surface), the conditions more closely mirror Earth’s own environment. For Landis, the Venusian sky is actually more like Earth than any other place in the solar system! And, were we to develop the tech to do so, building colonies there could work because Earth’s atmosphere, which is mainly nitrogen and oxygen, naturally floats on carbon dioxide… while Venus’ atmosphere is mostly CO2. All of which means we could theoretically recreate human-friendly environments above the definitely deadly, natural conditions on Venus. In this case, we’d survive on another planet by maintaining the optimum distance away from the ground.

And it isn’t an idea that’s exclusive to Venus, either. Sky-living could work almost anywhere in the solar system and beyond! Engineer Kenneth Roy proposed the idea of “hanging cities” back in the mid-2000s, and it’s effectively a combination of multiple terraforming plans. First, Roy envisions that we’d cover planets in a large shell of sorts, to contain and regulate an atmosphere similar (or even identical) to Earth’s. Then we’d build industrial spaceports on top of that shell as entry points only, and eventually we’d construct whole cities to be hung inside the shell using cables. It’s arguably the furthest of far-off dreams, but Roy argues that by using this method any planet, moon, or sufficiently sized asteroid could be turned into a safe, habitable, Earth-like environment.

Clearly, the prospect of human habitation anywhere other than Earth requires some truly innovative thinking. But whether it’s done via aerogel sheets, nuclear explosions, lava tubes, sky cities or sprawling shell worlds… those are the surprising ways that humans could survive on other planets.