What Happens If We Heat The Martian Core? | Unveiled
What Happens if We Heat the Martian Core?
Mars has been cold and uninhabitable for much longer than humans have been around to observe it. It has a thin atmosphere made up almost entirely of toxic CO2, no standing bodies of liquid water, and only 38% of Earth’s gravity. But Mars wasn’t always like this, and there may be a way to return it to its former glory.
This is Unveiled, and today we’re answering the extraordinary question; what happens if we heat the Martian core?
A study conducted by NASA’s Jet Propulsion Lab concluded in 2003 that Mars’ core is not completely solid. Based on observations about how the Sun’s gravitational pull affects the planet, JPL said that Mars’ core must be at least partially molten. It likely has either a liquid outer core or a completely liquid core. The former is much like Earth, which has a solid inner core and liquid outer core. The motion of this liquid outer core creates convection currents that distribute heat and, because of its rotation, a magnetosphere. Earth’s magnetosphere keeps the solar wind from stripping away our atmosphere, allowing the planet to sustain life.
Convection in the Earth’s mantle, which sits atop the outer core, is responsible for the movement of tectonic plates - large slabs of the planet’s crust that help form volcanoes and cause earthquakes. We know that Mars did once have tectonic activity, and so must have once had a more active core, because the planet has volcanoes and there’s evidence of earthquakes – or Marsquakes – having occurred in the planet’s past. The largest volcano in the solar system, Olympus Mons, is on Mars, and science has yet to tell us whether this monster – which is 2.5 times taller than Mount Everest – is active.
But while there’s concrete evidence that convection could be happening beneath the Martian surface, it’s not enough for Mars to hold onto its own atmosphere. In fact, Mars’s atmosphere is 100 times thinner than Earth’s, and this is the biggest barrier when it comes to the planet being habitable. It means that if humans ever go there, we’d either need to terraform the whole planet with ambitious and currently unworkable technologies, or we’d need to build risky, artificial habitats where a million things could go wrong at any given moment - killing the inhabitants inside.
One reason that Mars’s magnetosphere is weaker than Earth’s is the planet’s size. With about half the diameter of Earth, some experts estimate that even in its prime it was only formed with 10-15% of the internal heat that Earth was. Over time, this heat dissipates; and the heat generated by radioactive decay in a planet’s crust and mantle has a shelf life too. This is what happened to Mars between three to four billion years ago, and is what made it into the desolate, red rock we see in the sky today. It cooled down so much that it couldn’t generate a magnetic field anymore, and its atmosphere began to be stripped away by the sun’s deadly solar winds. This process is actually ongoing.
One of the most ambitious proposals to terraform Mars is to kick-start convection in the Martial core to create a new magnetosphere. Since Mars did have an atmosphere and may have supported all kinds of life for the first billion years of its lifetime, this could hypothetically be a workable solution. After all, the magnetosphere today isn’t completely gone, it’s just incredibly weak. There ARE a few other ways to give Mars a breathable atmosphere – for example pumping it full of greenhouse gases like the non-toxic perfluorocarbon, or PFC, faster than the solar winds can blow them away. But this would take hundreds of factories dedicated to spewing out gases on the planet’s surface. We might also be able to send a satellite equipped with a magnetic shield into Mars’ orbit, an idea that was actually proposed by NASA researchers in 2017. This might take the form of an large, electrified copper solenoid; but it would require a huge amount of power, and having sensitive equipment near such a big magnet poses its own problems.
So, remarkably, heating up the core to kickstart convection isn’t that crazy of an alternative. But how would we feasibly accomplish such a thing? We’d first need to come up with the technology to drill into the centre of a planet. Even with such a small amount of convection, Mars’s interior will still be very, very hot, and we’d need a metal capable of withstanding the incredible temperature and pressure. The go-to material for drilling is often diamond, which could do the trick. The temperature of Mars’s core is around 1500 degrees Kelvin, and in high pressure conditions diamonds can withstand over double that. However, you’d need to build all your equipment from something that could survive the heat, or the rest of it would melt. Then you’d need the means of heating up the core, for example using huge nuclear bombs. Once it gets hot enough, Mars would be able to finish the process itself.
However, transporting nuclear bombs to Mars, then taking them through molten tunnels of alien magma, then detonating them deep underground, sounds a little risky. And there’s no telling how many nukes you’d need to take with you. But despite the smaller size of Mars, it would still take an insane amount of energy to heat up the core of a planet, potentially more energy than we’ve ever used on Earth.
Our other option requires more patience, but there could be a way to use nuclear fusion, rather than nuclear fission. Fusion and fission are the two types of nuclear reactions that create energy. Fission is used in your standard nuclear powerplant, while fusion is the reaction that happens within the core of a star, which we haven’t yet been able to harness to generate electricity. If we found a way to do so in the future, we’d have a pretty good method for heating up Mars’ core.
In the best possible future, we would manage to build giant fusion generators deep within Mars to heat up the core and kick-start the magnetosphere. This would begin a new, golden age – or green age – of Martian history. Over time, Mars would become habitable again. Maybe not quickly enough for those who worked on the drilling to see it, but one day it would be able to support life. Mars sustained its atmosphere for roughly a billion years initially, so it could do so for at least this much time again, if not more if we kept the generators maintained. This is still more than long enough for Mars to develop life of its own, for those lakes and oceans it once held to reform, and at the very least to make it easily habitable for humans.
There is also one other possibility, however. Since Mars did form and start convecting all on its own at the dawn of the solar system 4.5 billion years ago, there is the slim possibility that it might naturally start doing this again without any need for alien intervention. Naturally-occurring crystallization in the core could potentially influence convection, and eventually switch Mars’ magnetic field back on. It’s a small chance, but it’s not impossible.
It may currently be impractical, but if we beat the odds and come up with some ingenious technology, heating up Mars could make the planet capable of sustaining life for billions of years to come. And that’s what would happen if we heat the Martian core.
