Astronaut or rover?

Univeristy of Cambridge public astronomer, Matthew Bothwell stars in this one and explains why the moon will likely become a more common destination for our astronauts over the next century... 

Chris - In the last few days NASA have announced the landing site for another rover. This one's going to be called Viper interestingly, and it's heading to one of the coldest places in our solar system, which is, Matt?

Matthew - The dark side of the moon

Chris - There you go. Not just a pink Floyd album. It is the south pole of the moon. That's where they're going. It's planned for 2023. Not NASA's only foray to our nearest neighbor out in space though, because there's the intention to land another crew member on the surface of the moon in 2024. This has got Joel thinking. He says, 'There's been a lot of discussion concerning a return to the moon. So why are we going back? Why can't we just send a Rover for that? Why send a human?'

Matthew - It's a really good question. I think there's a short term answer and a long term answer. In the short term it's useful to send people rather than robots to the moon because there's only so much you can do remotely. Human beings are really good at being adaptable and flexible and responding to things in the moment. If you notice something interesting looking on the horizon, or maybe you have some lunar dust on your experiments you want to clear, sorting that stuff out is trivial for humans. You can just wipe the dust off your experiments. If a robot hasn't been specifically designed to solve these problems it's going to run into some real difficulty. There are fiddly jobs that robots just can't do very well. For example, even to this day we don't really understand how heat from the interior of the moon diffuses out to the surface. That's because the astronauts in the Apollo mission tried to drill holes and their technology wasn't very good. They had trouble drilling holes. It's just too fiddly a job for a robot. We're going to have to send a person there to do it that way.

Chris - Why are we interested in heading back to the moon at all? Haven't we got bigger planetary fish to fry these days like Mars?

Matthew - We absolutely do but I think the first step towards frying those planetary fish is going to the moon in the coming century. We want to be exploring the whole solar system. We're going to Mars and that's just the beginning, right? We want to be going beyond Mars and exploring all of our cosmic home. I think human missions to the moon are a great proving ground for all the technology that we're going to need to help us along the way. It's very hard to test equipment in the environments on Mars, but the moon is basically next door in terms of space. It's a really nice first step to our coming adventures.

Chris - Is it a jumping off point? because some people have speculated that we put a base on the moon and then it's much easier to go places from there, rather than having to keep getting off of earth into space and then on to our next destination?

Matthew - True, Earth is a big planet, right? We're sitting at the bottom of a very deep gravity well and that's why you need such an enormous rocket to blast off into space. Gravity on the moon surface is about a sixth of the gravity on the earth surface. Getting into space from the moon is much easier. We're building these permanent installations, like a moon base, and that's going to be an orbiting space station around the moon a bit like the ISS, and getting into space from there rather than from earth should be much easier in the future.

Chris - Do you know where they're going to build these bases? Will we be able to see them from Earth? Presumably they will want them on the side facing us so we can talk to people easily because if they were around the other side they wouldn't better talk to us so easily!

Matthew - Yeah, that's exactly true. Any base with people in it is going to be on the near side of the moon, so it can radio Earth. There are reasons to go around to the far side of the moon as well. There are plans to build a radio telescope on the far side of the moon, which is going to be one of the quietest places in the solar system because you can have thousands of miles of rock between your radio telescope and the noisy radio Earth. In terms of exploring the distant universe we might be going to the far side. I think we're going to be exploring just more of the moon in the future in general.

Chris - Out with one of your big telescopes, doing your public astronomer bit, would you be able to see the settlement or would it be just too small?

Matthew - I think the settlement stuff they've planned will be too small to start with, but you never know what the future may hold. If there ends up being a permanent settlement of people on the moon, then in fifty years, a hundred years, it really might start getting quite noticeable.

Chris - Watch out, you might have Matt staring at you future moon inhabitants.