Simon Morden “If life is simply a question of the right environment, then yes, Mars had life”
Planetary scientist and award-winning sciencefiction writer Dr Simon Morden talks to All About Space about his obsession with Mars and his latest science-fact book on the Red Planet
In The Red Planet: A Natural History of Mars, you vividly describe what it’s like to be on ancient Mars. How much of this is scientific fact versus artistic licence?
Over the last 50 years, we’ve built up a considerable body of evidence that tells us what Mars was like at various points in its long history – what the climate was like, what the volcanoes were doing, where the rivers and lakes and oceans were – so while it’s an act of the imagination to describe what it would feel like to sail on the Martian sea or sample gases erupting from fissures on primordial Mars, everything there is backed by peerreviewed papers.
Do you think life ever existed on Mars? If so, do you think we’ll ever find evidence of it?
A lot turns on the answer to the question how
inevitable is life?. If life is simply a question of the right environment, then yes, Mars had life. Conditions in the early Martian ocean were pretty much identical to those in early terrestrial ones: there would have been mineral-rich hydrothermal vents pouring a cocktail of energyproducing chemicals into the deep seas. If those chemicals had the same capacity for self-organisation as they did on Earth, then simple life would have spontaneously appeared.
It’s a very long way from a single-celled organism to something we might recognise as a fossil, though. Until we get a lot more rocks, and from the right places – the ancient ocean floor, specifically – we won’t be able to say with any confidence one way or the other.
Where would you like to see the next lander or rover mission go, and why?
For the reasons above, I’d like to put something down on the vast plains of the north, where there was once a deep ocean. I’d be looking for those relics of hydrothermal vents and having a really good dig around. If we can identify some of them from orbit, even better.
What do you think the next really big Mars discovery is likely to be?
If the science is correct, then Mars has had continuous volcanic activity for almost its entire history – from the very earliest volcanoes we can identify to the very latest ones on the plains south of Elysium. Those lava flows appear to date from barely a few million years ago, so I remain sceptical that the planet has actually decided that now, relatively speaking, is the time to stop erupting. Active volcanism on Mars is my call.
NASA is targeting the early 2040s for the first boots on Mars. What could astronauts do there that robot missions can’t?
The robots are absolutely brilliant, and our ability to get them there and have them (mostly) work is at the very limits of our technology. But people bring a whole different skill set to bear. They’re adaptable – an
“Putting people on another planet will inspire a whole new generation of scientists and engineers, and writers and artists too”
astronaut is able to carry out a vast range of tasks. They’re also much faster decision makers. It takes, at best, minutes to send a message to Earth and have a controller decide what the robot will do next, then minutes more to send the instruction and yet more minutes to see if that worked. A human on the ground will be able to cover more ground and do more science, even if their time on the surface is limited by other factors. There’s also the undeniable wow factor, which mustn’t be discounted. Putting people on another planet will inspire a whole new generation of scientists and engineers, and writers and artists too.
Do you think it would be worth terraforming Mars in the distant future?
I think terraforming is very much the grand folly of projects. If our technology is advanced enough to turn Mars into an Earth-like world, we wouldn’t need to. That same technology would be more than sufficient for us to transform not just the way we live on Earth, but the way we’d live in space. Building vast orbital habitats around any planet we choose would be an order of magnitude easier and faster than any terraforming scheme.
What’s your favourite geological feature of Mars, and why?
This is worryingly like asking me which is my favourite child! There are many candidates, but I think I’d have to go for Korolev crater. It sits on the high northern plains, is almost a perfectly circular 80 kilometres (50 miles) across with high, defined walls and inside it is a vast lens of bright water ice that stretches 60 kilometres (37 miles) side to side and nearly two kilometres (1.2 miles) tall. It’s startling and beautiful.
Was there a point when Mars and Earth were much more similar than they are now, and what made them go off on different evolutionary trajectories?
Very early on – the first 600 to 700 million years, possibly up to a billion years – both planets would have superficially looked similar: barren land, oceans and lakes that may or may not have had simple life. But the differences between Earth and Mars were baked in from the very start, and it just took some time to unwind. Mars is significantly smaller, and for whatever reason it couldn’t sustain either a system of plate tectonics, which recycles the crust and moves water into the deeper mantle layer, or a planetary magnetic field that protects the atmosphere from being stripped by the Sun’s radiation. Earth remained a rich, dynamic planet, while Mars slowly became a gasping, stagnant one.
Mars has changed radically from one era to the next. What does the next billion years hold in store for the Red Planet?
One of the curious things about Mars is that because it doesn’t have a large moon to stabilise its axis of rotation, it flops around in an entirely chaotic and unpredictable manner. Currently, the axis is at 25 degrees to the orbital plane, similar to that of Earth, and it has summer and winter seasons just like us. But in the past the axis has been anywhere between 0 and 60 degrees, and this has enormous effects on the Martian climate. If the axis was at 40 degrees, both ice caps would melt and we’d see free water on the surface of Mars again. And this wouldn’t take a billion years… a few thousand would do it.
Total Recall or The Martian?
At least you didn’t ask me to choose between War of the Worlds and John Carter of Mars! The problem with The Martian – as epic as it is – is that I know too much and can see where the science has been tampered with. Total Recall doesn’t pretend to be accurate at all – everything there is to service the lurid plot. So as much as I enjoyed Matt Damon’s survival antics on the Red Planet, I’ll go with Arnie and get my ass to Mars.