Jeff Bezos. NASA. Especially Elon Musk. All are dreaming of transforming Mars from a red dust bowl into a blue-green heaven. All are spending up big in the hope of eventually making it so.
Problem is, it's probably impossible.
A study published yesterday in the science journal Nature Astronomy and the discovery of a frozen lake under one of the planet's poles has poured cold water on the idea.
More specifically, it hasn't.
There's not enough water to create the planetary network of oceans and lakes necessary for a stable ecosystem.
"It is a fixer-upper of a planet," Musk said in 2015. "But eventually you could transform Mars into an Earth-like planet."
The billionaire entrepreneur has some rather direct ideas about how.
"You'd warm it up", he said.
"There's the fast way, and the slow way …"
You decide which is which.
One idea is to drop nuclear bombs on the north and south pole to melt the ice and kick the vapour and dust up into the atmosphere. It may take a million years for the radiation to dissipate, but who's in a hurry?
His other idea was to do to Mars what we're doing here on Earth: flood the skies with carbon dioxide and induce global warming. His suggestion to release the carbon dioxide in the red planet's poles and soil - create a series of small, artificial suns in orbit.
Elon Musk speaks about his "Interplanetary Transport System" which aims to reach Mars with the first human crew in history. Photo / AP
Under pressure
Mars' atmosphere is very thin. It's one of the reasons why landing there is so difficult.
Spacecraft use atmospheres to slow down, and then generate lift, as they sink towards the surface.
Mars just doesn't have a lot of 'stuff' in its skies to provide either that drag or lift.
Any humans walking its surface will have to wear hefty space suits in order to breathe — and survive the background radiation.
This will have to change — both for making breathing easier with stable oxygen contents, as well as enabling liquid water to sit soundly on the planet's surface. If the atmosphere is too thin, water and oxygen simply evaporate away into space.
Here on Earth, our atmosphere is measured as 1000 millibars at sea level. It's made-up of 78 per cent nitrogen, 21 per cent oxygen. Carbon dioxide, nitrous oxides, methane and ozone account for a fraction of one per cent. But that carbon dioxide is particularly powerful when it comes to trapping the Sun's rays.
We know there's abundant carbon dioxide on Mars: it makes up most of its wispy skies, and is embedded in rock and ice.
But is there enough in storage to boost atmospheric pressures by any meaningful level and create a stable, planet-warming blanket?
Bruce Jakosky of the University of Colorado Boulder and Christopher Edwards of Northern Arizona University have done the math. They've analysed surveys of Mars to estimate how much carbon dioxide is available. They've calculated how much is needed to reach 1000 millibars.
Their findings:
The 'dry ice' (frozen CO2) caps that makes up the north and south poles are actually quite thin. Even when combined with that embedded in rocks, there's only enough to create about 15 millibars of pressure.
Musk disagrees.
"There's a massive amount of CO2 on Mars adsorbed into soil that'd be released upon heating," he asserts, without detailing how he knows. "With enough energy via artificial or natural (sun) fusion, you can terraform almost any large, rocky body."
And this freshly discovered subsurface lake isn't likely to be palatable.
This artistic rendering shows the Mars Express Spacecraft probing Mars' south pole as radar signals appear at left. Photo / AP
It's estimated it sits in a zone which is somewhere between -10C and -30C. To be liquid at those temperatures, it would have to be very, very salty.
All up, the discovery indicates Mars has long since lost almost all its water.
We know it was there: we can see the fossilised streams, rivers, lakes and oceans. And our robotic rovers have found more than enough examples of sedimentary rock that can only be formed under water.
But that water has long since boiled off into space.
It's atmosphere wasn't thick enough to maintain the water under sufficient pressure for it to remain liquid, nor keep enough carbon dioxide in the skies to trap enough of the Sun's warming rays.
A cutaway plan for Elon Musk's proposed 'BFR' vehicle, capable of carrying cargo - and people - to mars. Photo / SpaceX
Full steam ahead
Musk plans to have two of his Space X 'BFG' rockets headed to Mars with prepackaged supplies by 2022. Two years later, another 'BFG' will carry the first humans to the red planet.
It's a big step for those men and women on the mission. It'd be a giant leap for Musk's ego.
But will it be the first step towards building a better world?
Musk says he's figured out a way to pay for it all (by offering a 30minute rocket trip to anywhere in the world - to paying customers).
He says he wants to combine the different spacecraft his SpaceX already has - Falcon 9, Falcon Heavy, and Dragon module - into a single ship. He's code-named it "BFR" - for Bick F*&^ing Rocket.
It will be launched into orbit, where it will be refuelled. It will then head to Mars, where prepositioned supplies will sustain its cargo of 40-80 peoople.
"I feel fairly confident that we can complete the ship and be ready for a launch in about five years," he said last year. "Five years feels like a long time to me."
His goal?
To build a base. Turn it into a city. Then terraform Mars.
He's never elaborated on his project to make Mars inhabitable beyond his few media appearances. It's not as though he'll be alive to answer to investors then, anyway.
One thing for certain, Musk sets himself high goals. In this case, he's truly aiming for the stars.
"I think fundamentally, the future is vastly more exciting and interesting if we're a space-ranked civilization and a multiplanet species than if we're not," he told an International Astronautical Congress in Adelaide. "You wanna be inspired by things. You wanna wake up in the morning and think, 'The future's gonna be great.' That's what being a space-ranked civilization is all about. It's about believing in the future, and believing the future will be better than the past."
