Life on Mars

Is there life on the red planet? How can we find out?
29 May 2018

Interview with 

Andrew Coates, UCL’s Mullard Space Science Laboratory


Certain Earth-like systems are just too far for us to reach. So to search for an alternative home, astronomers need to look closer to our blue dot. Specifically, Mars. Izzie Clarke sat down with Andrew Coates, from UCL’s Mullard Space Science Laboratory, the principal investigator for a panoramic camera that will be visiting the red planet as part of a new rover mission called ExoMars 2020. But how are scientists exploring Mars?

Andrew - Well what we're doing at the moment is using a combination of orbiters and rovers, currently Masser has the curiosity mission on the surface looking for signs of water and habitability and what we want to do in the future is actually to extend that search now and look for signs of life and so we have the European Space Agency and Russian mission called ExoMars that's going to the surface of Mars. And what we'll be able to do with that is actually drill underneath the surface of Mars for the first time up to two meters. The surface of Mars is a very inhospitable place at the moment because it's got pretty thin atmosphere which means you have a high radiation environment high ultraviolet environment. It's also a very oxidizing environment and thin carbon dioxide atmosphere so it's not conducive for life now but underneath the surface that's where we hope the evidence for life having been on Mars, that's where it will be.

Izzie - So how do you know where to drill. Because obviously we're down here on Earth. How can you control that.

Andrew - That's one way to do that is with the instruments which look at context. So our one is the main context instrument really, the Pancam panoramic camera system inside the box. Basically we have three cameras so the two of them are wide angle cameras and these are spaced 50 centimetres apart. So with that we get stereo reconstruction and better than the human eyes can do. Each of those cameras actually has a little filter wheel on the front of it. So this has 11 filters for each of the two cameras. So with that we split up the light into its constituent colours and measure basically the reflected spectrum of rocks. We're trying to identify the rocks and in particular water rich minerals to see where the right places to drill for signs of life.

Izzie - How would this all work together because it's got quite a lot of different instruments on this rover.

Andrew - Yes so with the context instruments of which pan cam is one and then we get the other context as well. We actually get a sample from underneath the surface, so it drills underneath the surface and so we get the sample from there bring it up and put it on the same Rover into the analytical draw. And so there are more instruments inside the analytical draw to actually look for signs of life on Mars.

Izzie - Obviously all of this - No humans! How far away is that?
Andrew - The problems with sending humans are the expense of doing it. Twenty thousand dollars a kilogram to launch anything into space at the moment. So by the time you've sent a person, the water, the food it's a lot of kilograms and a lot of money to actually do that.

Izzie - Because Elon Musk has said that it can be possible, he's got this blueprints to colonise Mars so he's only a bit more about that. What does that involve.

Andrew - Yes so he is building a very large rocket system. I mean currently they have the Falcon Nine which can read land. The launcher actually back on Earth and that helps to save cost. But what he's doing now is building something called a BFR which stands for big something rocket and we think that something is Falcon

Izzie - Not something else!

Andrew - But it really is big and that potentially could be taking 100 people to Mars.

Izzie - So how long is he planning to do that? Can they stay there? What are some of the problems
with it?

Andrew - Well he says that they want to launch the first two missions in 2022 and then in 2024 maybe take a couple of people to Mars. I think that is wildly optimistic because of course they've got to develop the technology to be able to do that. They want to try and use the surface of Mars using water from the under the ground, carbon dioxide from the atmosphere to make methane and oxygen and so with that you could build the fuel to come back. Now this is the realms of science fiction really. There's a lot of things to do. First of all landing in this very thin atmosphere. The other big challenge with Mars is Mars doesn't have a global magnetic field so unlike the Earth which has a magnetic field which help to shield us and our atmosphere from radiation from space that is dangerous to humans. And so actually having that on the surface and being able to deal with it even taking people there at all that's something which has to be really thought about.

Izzie - Are there any plans on if we were to stay on Mars, how we might live there what life would be like would we even be able to have a houses. How could we build anything like that.

Andrew - We wouldn't be able to do that very easily because there are a number of differences, I mean the atmospheric pressure is low. It's carbon dioxide atmosphere so obviously you have to have an atmosphere including oxygen. So that would be done inside probably huts or whatever or you know things that you built on the surface. So so you'd need that type of arrangement. You need to keep the inhabitants warm. You need to - of course - grow food and things like that. So I mean people talking about colonisation. Elon Musk of course is one of the people who has wonderful plans for that. But you know the technical challenges of doing it the difficulties are certainly quite significant at the moment. We don’t have the technology to do that.

Izzie - And how optimistic are you. Do you think it could be done.

Andrew - I think potentially it could be done if the political will and the money and so on was there one could get over the technical challenges. It’s always great to aim high and have the possibility of solving the technical problems to do it. But no we'll take a little while to actually do that.


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