Chris Hadfield: Are we on the brink of finding ET?

James - Speaking as a producer of science radio programmes, it feels like a really exciting time in astronomy and space science. The first thing I wanted to get your view on is the recent resurgence of interest in the Moon and getting back there. We had India's Chandrayaan launcher just recently, Russia and China have expressed interest, thoughts of a lunar base. What's the timeline on this sort of thing?

Chris - Well, I think the biggest driving discovery has been water on the moon. If the moon is an inhospitable desert, then you have to bring every single thing with you and it's no place you're going to want to live. But over the last decade, our sensors have found vast reserves of water trapped in the shaded parts of the moon, especially at the South and North Pole on the order of 400 billion litres. And so if you have power from the sun like we do at the poles, because the sun is always visible and you have vast reserves of water, then what you really have is Sunny Waterfront, and everybody wants to live at Sunny Waterfront! That's the real estate on Earth and that real estate is now being very much contested. China have said we are going to have Chinese astronauts walking on the moon by 2030.

Chris - And there's already a crew, including three Americans and a Canadian, who are assigned to go to the moon probably early in 2025 and all those missions after that. There are 77 national Space Agencies in the world, not just the UK Space Agency and NASA and whatever, but 77 countries. All of them realise this is a huge new continent of resources and opportunity. With our improved rocket technology, with SpaceX and such radically dropping costs, suddenly it's like we've gone from sails to steam. Suddenly, this is now way more possible than it was even a decade ago. I'm very much involved with that, with technology incubation, with the Open Lunar Foundation, which is looking at what laws should be and how to influence it. I'm working with King Charles on a project called the Astra Carta to look at how we can make all of our efforts think about the long term and the ethos of it and the sustainability of it. I'm very much involved in that.

James - The other thing totally revolutionary for space science at the moment is of course the James Webb Space Telescope. One of the most exciting discoveries recently, from my perspective, has been K2-18 b, the exoplanet where we've found methane and the tentative suggestion of dimethyl sulphide: the so-called slam dunk chemical for life. The prospect of life elsewhere in the universe is really starting to grow.

Chris - For the last dozen or 15 years we've been able to detect planets around other stars. But what the James Webb Telescope gives us is a technical capability to see the atmospheres of those planets. With the stars behind them, you can look at how the light is changed as it comes through their atmosphere and look at the spectrum and see what's being absorbed and therefore find out that there is methane and other telltale life chemicals prevalent in the atmosphere and that's really tantalising. Are we alone or not? That little helicopter on Mars has flown over 60 times now, and the big rover is drilling down into Mars, looking for fossils, looking to see if life ever developed on Mars. We're going to send a probe to Europa, which has more water on it than Earth, and it's warm water. So there may be life on Europa and maybe James Webb will see something that is conclusive to show us definitively that we're not alone in the universe. As much as UFOs are fascinating and extraterrestrials make for great movies, we have never had any actual proof or evidence of life except from Earth so far. And maybe we're right at that moment in history where we're going to find out that there's life elsewhere.

James - And on that note, Chris Hadfield, thank you so much for your time.

Chris - Thanks James. Lovely to talk with you.