Another Earth?

Is it possible to find a second planet to live on?
06 June 2017

Interview with 

Professor Stephen Hawking, Cambridge University; Garik Israelian, Starmus Festival; Claude Nicollier, European Space Agency; Simon Evetts, Blue Abyss


Could you imagine living elsewhere? We’re not talking about a new home or town but a different planet! Recently, Professor Stephen Hawking has said that we have 100 years left to colonise a new planet. He, along with other eminent scientists will be speaking at Starmus Festival in Trondheim later this month. This five day festival is a celebration of science and music, and it’ll be at Starmus where Professor Hawking will reveal just what the problem is. In the meantime, Izzie Clarke went to an event at the Royal Society in May to investigate what needs to be done to find an alternative Earth…

Stephen - I strongly believe we should start seeking alternative planets for possible habitation.

Izzie - Even from Professor Stephen Hawking himself, it sounds like an impossible challenge. Can we really find and colonise a new planet within the next century? With climate change and the global population continuing to increase, is there a plan - or planet - B? I spoke to astronomer and Director of Starmus Festival, Garik Israelian to found out what conditions we’d need to survive on an alternative Earth.

Garik - We were part of the evolution for millions of years. It’s very deep in our genes to have the daylight that we have, the magnetic field of the Earth that we have. We would need the same gravity, so we don’t really know, if you change those conditions slightly - lets say 10% of the magnetic field, 10% of the daylight - what will happen to us? How are we going to evolve as creatures?

Izzie - Are there any possible planets that we might be able to relocate to in the next 100 years?

Garik - No. We don’t know any now. The only thing that astronomers find from time to time are planets where you can have liquid water. But we have no idea about magnetic fields in those planets; we have no idea about atmospheres so all these parameters that we have for the Earth. But I don’t think that having a planet with the mass of the Earth and with liquid water is enough.

Izzie - So more research needs to be done into finding an alternative Earth. Earlier on in the year, scientists from the University of Cambridge found signs of water on a planet within Trappist 1, a planetary system 39 light years away. That’s quite a long way to go without knowing other environmental factors! But imagine if we had found the perfect planet - how do we get there? What, in terms of technology, is holding us back?

Claude - I’m Claude Nicollier. I was a European Space Agency astronaut for 25 years. The two major problems in technology development for the next few decades for going to the solar system will be protection against radiation and the proper propulsion system.

The problem is, if you go outside of the vicinity of the Earth towards the Moon, or Mars, or satellites of Jupiter or Saturn, we need to protect the crew against radiation. Once we are on the surface of another celestial body, we can build habitats where there is protection. If we are on Mars, we can use Mars material to cover the habitat so that we are protected, to a certain degree, against radiation.

For the rest we need, of course, propulsion systems that allow us to go from one place to another in the solar system using something other than chemical propulsion. Chemical propulsion doesn’t give us enough efficiency and capability to travel.

Izzie - Do you know of any further work that’s being done to reach that?

Claude - Lots of testing is being done on nuclear propulsion or, lets say, was done in the 60s mainly and then it was kind of abandoned. We are starting now again to look at new propulsion systems and once you are in space you can use electric propulsion where you ionise a material, then you accelerate the ions using an electric field. The problem with electric propulsion or what’s very efficient, is the thrust is very low. So you cannot leave the surface of a celestial body, be it the Earth, or Mars, or any other body in the solar system using electrical propulsion. But to go from one place to another, if you have enough time, you can do it.

Izzie - It’s safe to say we need to improve our propulsion systems and radiation protection. But what about the human body? Can it actually cope with such a long journey? I spoke to Simon Evetts, a space physiologist who’s creating the first commercial astronaut training centre Blue Abyss…

Simon - When we’re in space and gravity is taken away from us we have less need to contract our muscles. There aren’t heavy things to lift up and we don’t move our heavy body around, so our muscles and our bones decondition - they wither if you like.

Izzie - What are some of the other factors that will affect us living in space?

Simon - Radiation is currently one of the showstoppers, whether it be galactic cosmic radiation or solar flares. High energy particles can hit the body and hit the cells, and these can damage and mutate cells increasing the risk of cancer which is, of course, something we want to avoid. We see reductions in immune capability that occur over long periods in space. All of these things add up to basically deconditioning and degrading the body and our physicality.

Izzie - Can we live in deep space for a long period of time?

Simon - Using the same systems that we have now, then I would say no. It’s very unlikely that we would do so because the body de-conditions so much and the individuals involved would be in a weak state when they arrived at the planet, X number of months or years away.

What we need ideally is, rather than a number of systems and a number of devices to be able to help us, we need to take gravity with us. So we’re talking about spinning space ships, we’re talking about human centrifuges in space. Because if we’ve got artifical gravity with us then all of our systems are being affected and stimulated in the same way that we tend to find on Earth.

Izzie - Right. So all we have to do in the next 100 years is to find a new planet with the same mass, atmosphere, and magnetic field. Develop a new propulsion system and, ideally, have a spacecraft that generates artificial gravity and protects us against radiation!

Stephen - We are running out of space on Earth and we need to break through the technological limitations preventing us living elsewhere in the universe. I am not alone in this view and many of my colleagues will make further comments on this at Starmus next month.


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