Why Lava Tubes Could Hold The Secret To Life On The Moon And Mars | Unveiled

Why Lava Tubes Could Hold the Secret to Life on the Moon and Mars

Is there life out there beyond Earth? It’s one of the biggest questions of our time, with increasing numbers of scientists dedicated to searching the stars for evidence that we’re not alone in the universe. And, according to some, alien life could still be hiding just beneath the surface of our very nearest neighbors in the solar system. We just need to make sure we’re looking in exactly the right places…

This is Unveiled, and today we’re exploring the extraordinary ways that lava tubes could hold the secret to life on the moon and Mars.

Lava tubes are exactly what they sound like. The product of volcanic eruptions, they’re created when a lava flow develops a hardened crust on the outside, while molten lava continues to flow underneath. Eventually the lava inside drains out and what’s left behind are unique caves, some of which are extremely long. They’re generally found in the most volcanically active parts of our planet, like Hawaii, Iceland, and the Canary Islands. Some, like the tunnel “Raufarhólshellir” near Reykjavik, are even open to the public. And while they may sound dangerous or at risk of collapse, many have stood for thousands of years and are very stable.

But Earth isn’t the only place in the solar system that has volcanoes, and so isn’t the only place that has lava tubes. There are many places in outer space with volcanoes; Jupiter’s moon Io, for example, is the most volcanically active body in the entire solar system. Io appears bright yellow because it’s covered in sulfur from countless eruptions. The moon is far too volatile and toxic to ever be a viable location for a human colony, but there are much nearer idylls that have volcanic activity. The moon and Mars both boast lava tubes as well, much like Earth’s only far larger. Currently, the moon is not volcanically active, but it was millions of years ago. The moon’s dark gray patches, its “maria”, are made of ancient lava flows, for instance. We also don’t know for sure whether the moon still has a molten, magma interior, though it seems very likely that it does.

Mars, on the other hand, is home to the tallest mountain in the entire solar system, Olympus Mons, and Olympus Mons is also a volcano. It’s not the only volcano on Mars, either, just one of many. Its peak is 13.6 miles high. That makes it more than double the height of Mount Everest, which is around 5.5 miles above sea level. Olympus Mons is also a shield volcano, which is especially important because shield volcanoes are the best at producing the lava tubes we’re interested in. On the moon, the tubes are formed slightly differently by powerful lava flows that eventually sink beneath the surface after an eruption. But in every case, what we’re left with are large, underground caverns.

We’re particularly interested in these lava tubes for two reasons: one, they’re ideal locations for human bases to be built when we eventually leave Earth; and two, they could be hosting evidence that life exists or once existed on these celestial bodies. In both cases, the lava tubes are ideal because they’re relatively protected from the environmental extremes of the lunar and Martian surfaces. The moon is inhospitable to life because of its exposure to radiation and wild temperature fluctuations. Lunar daytime lasts for two weeks, meaning that a base built anywhere except in a lunar crater is exposed to the full force of the sun half the time, and plunged into freezing darkness the rest. At its coldest, the moon is -208 degrees Fahrenheit, and at the warmest, this skyrockets to 250 degrees Fahrenheit, way beyond the temperature gradient humans can survive at. This is why many proposals for human lunar bases focus on the moon’s poles, specifically the enticing South Pole-Aitken Basin, where the walls of the crater could protect us. But the lava tubes are another step beyond this, places with much more stable temperature gradients to work with.

Astronomers have already spotted what might be entrances to lunar lava tubes, nicknamed “skylights”, which means we could access these tubes without having to dig or mine at all. The tubes are also far larger than the ones on Earth, with scientists theorizing that some lunar tubes could be over half a mile in diameter. So, there’s certainly plenty of room for humans to build whatever we want down there, and we’d have a far easier time than if we were to try and construct shelters on the lunar surface. On the surface, our habitats would have to withstand both of those temperature extremes. While we already have a habitat that can do this in the form of the International Space Station, the ISS is only scheduled to last around thirty years. We’d likely want any permanent lunar bases to last much longer, and shielding the habitats from such extreme conditions is a good first step. You would also be less exposed to deadly solar radiation in the caves. Protecting astronauts from radiation is a problem NASA still hasn’t solved, and is a major reason astronauts can’t stay in space indefinitely. Even though the ISS is in Low Earth Orbit and therefore subjected to less radiation than you would be if you were truly in outer space, radiation remains a massive problem.

Many of the same things hold true for Mars, even down to the “skylights” that have been identified on the Red Planet as well. Thankfully, Mars is less extreme than the moon in a lot of ways. Though its atmosphere is extremely thin, Mars’s atmosphere is still better protection against the sun than the moon’s, which is even weaker. Temperatures also stay in a more acceptable range. Though at its lowest point it can be -200 degrees Fahrenheit, the warmest temperature we’ve ever recorded on Mars was a mild 70 degrees. Inside the lava tubes, which are also expected to be much larger than Earth’s, the temperatures would be even more stable. Building habitats underneath the Martian surface would be even better than building them on the moon, though we’d still have to overcome the large distance between us and Mars in the first place. Once there, though, this is the best option for building a safe human outpost. Plus, since they could be the least-hostile part of the entire planet, Mars’ lava tubes could potentially host evidence of alien life. We’d need to go there with probes and robots to study this for ourselves and see if there are microbes – or perhaps even larger organisms – calling the caverns their home.

There are still more benefits to building bases in these lava tubes. On both the moon and Mars, going underground into the lava tubes would protect intrepid explorers from impact events. Asteroids burn up when they reach Earth because of our planet’s robust atmosphere. But that’s something the moon and Mars don’t really have, meaning they’re far more susceptible to deadly impact events. While caves can’t provide shelter from every impact event and could collapse, they’re still going to offer more protection than if we were on the surface out in the open.

Finally, though, in the case of the moon, those lava tubes could bring us even closer to water ice. Scientists have long known that there is water ice on the moon, an invaluable resource for astronauts looking to build a settlement since it means they don’t have to rely on getting deliveries of water from Earth. Water is heavy and journeys even to the moon take days, long enough for dehydration to become lethal, so having a reliable and local source of water would be essential. Large ice deposits could be more accessible if we can get underground via the lava tubes. And once again, there’s the potential that these water molecules could be supporting or preserving alien life of some kind – but we’d need to go there to check.

There are still some downsides it would be irresponsible not to mention, however. Namely, there would be a mental toll from living underground. Astronauts are already put under tremendous psychological pressure, doing one of the most difficult, dangerous, and stressful jobs in the world. If they were also confined to an underground bunker with no way to easily see the stars or Earth, they could become even more mentally strained than they would have been in a base on the surface. But these problems aren’t inherent to underground bases, and any astronaut going to live on the moon or Mars would have undergone rigorous evaluation; would be supported by the best doctors in the world; and would know exactly what they signed up for.

This network of extra-terrestrial caves could support not only humans, by providing environmental protection and water ice, but alien life as well. And that’s why lava tubes could hold the secret to life on the moon and Mars.