Astronomy

“A village on the moon”

Fifty years ago, on 21 July 1969, humans stood on the moon for the first time. To celebrate the anniversary of the moon landing, UZH astrophysicist Ben Moore has written a biography of the moon. In this interview he tells us about the new space race, and explains how the Earth’s satellite came into being.

Thomas Gull

 

Ben Moore, you have written a biography of the moon. What does the moon mean for you?

Ben Moore: I love the moon. It’s an object of beauty. The more I’ve learned about the moon, the more it means to me – because of its role in the history of life on our planet and the history of our culture. But most of all I just like to look at it, through my telescope.

You say the moon is extraordinary. What features make it stand out?

It’s the most spectacular astronomical phenomenon that we can see with our own eyes – we can’t look at the sun directly, but we can see the surface of our Moon. The moon is the dominating object that we see at night. Throughout history people have loved the moon and wondered about the mystery of it.

The moon is not a mystery any more. Isn’t that a bit sad?

Is it sad? I don’t think so. Some of the old myths were a little bit crazy – like the idea that the moon could make you go mad, which originated in Roman times. Today we know scientifically that the moon does not influence humans. We know a lot more about the moon now than we did before the first moon landing in 1969. But there’s still a lot that we don’t know.

Like what?

The Apollo missions collected moon rocks which have enabled us to learn a lot – not only about the moon, but also about our solar system. The material we find on the moon documents the history of our solar system and tells us what conditions were like long ago. And we’ve learned that the moon is a sibling of the Earth. It’s made of the same material as the Earth and was once part of Earth.

That means the moon and the Earth separated at some point. How did that happen?

The theories about how the moon was formed have changed several times since the 17th century. But after the Apollo landing, all the existing theories were ruled out. A new theory was proposed in the 1970s, that the moon formed because a planet the size of Mars had collided with the Earth – 4.5 billion years ago. The debris that was sent flying into orbit as a result coalesced to form our moon. But that theory now has problems, the moon rocks are just too similar to the Earth – there is no trace of the impacting planet and we are working hard on trying to understand why.

You are simulating the creation of the moon?

Yes, for about two years I’ve been working on that together with my PhD student Miles Timpe. We are using the Swiss National supercomputer in Lugano to run more than 10,000 different impacts between planets to try to find the configuration that led to the formation of the Earth and the moon.

Do you already have an idea?

We think it probably wasn’t a small collision that led to the moon splitting off.

What could it be then?

It’s likely that first of all two equally large planets merged together to form the Earth. From this fusion an early form of Earth came about that was spinning rapidly about its axis. This rotation caused material from the Earth to be scattered into orbit, from which the moon was formed. That fits with the theory developed by George Darwin (1845-1912), son of Charles Darwin, back in 1878. Darwin, however, wasn’t able to theoretically rotate the Earth fast enough to cause parts of its matter to be scattered into space. We think we have now managed to do that.

In your book you recall the last time humans were on the moon – you saw it!

That was the last Apollo mission in December 1972. I was six years old, my father took me outside and said “Look son, there are astronauts up there on the moon right now.” I thought we could actually see the orbiting command module waiting to return the astronauts to Earth.

That was a long time ago. You think we should go there again. Why?

Space is inspirational. Many people are fascinated with the idea of travelling to Mars. But in my opinion it’s unlikely that we’ll manage that in my lifetime. However, we could return to the moon relatively easily and build a lunar village to carry out space research and even to host space tourists.

Holidays on the moon?

The great thing about the moon is that you get a fantastic view of the Earth.

Would you like to see that?

I’d love to see that. From Mars, Earth just looks like a faint star. But from the moon you can see the continents and the clouds slowly rotating by.

Should we colonize the moon?

Definitely! The most important reason to construct a permanent settlement on the moon is in order to carry out science, to learn more about our moon and to prepare for more ambitious journeys. Ultimately, we want to travel to Mars and the stars beyond. To do that we need to go back to the moon, to find out about the effects on the human body of a long stay in space, and to develop life-support systems etc – the moon is the ideal starting point for our ultimate exploration of the galaxy.

Would it be expensive to colonize the moon?

It would cost less than one percent of what we currently spend worldwide on military defense. We have the money and the knowledge to do it.

How could we live on the moon?

The moon has no atmosphere, so we’d have to build compartments in which we could live and breathe without special equipment. An ideal location would be the deep craters on the lunar poles which contain abundant water ice.

Who would do it – private companies?

I don’t think so. At the moment there are no private companies with enough money and know-how to do something like that.

Who else could achieve it?

My guess is that the Chinese that will return to the moon first.

The Chinese are prepared to invest that much?

And to take the risk.

When will there be a permanent settlement on the moon?

We’re in a new space age. All the main space-faring nations have announced that they will build lunar villages that will be permanently occupied by astronauts within the next ten years.

That sounds quite ambitious.

It is doable. A space race will help achieve this goal because everyone wants to be first back there.

You say that we will not visit Mars in your lifetime. When will we?

I imagine about 50 years from now.

Mankind on the moon. How does the story end?

That’s just the beginning of the story. Then it continues to Mars and Alpha Centauri and from there to fill our galaxy with life. If there isn’t already life out there.

Book presentation

Ben Moore: Mond. Eine Biografie, Verlag Kein & Aber 2019.

Ben Moore will launch his new book at Kosmos on Friday 17 May: Ben Moore at Kosmos – Cosmic Talk & Book Launch, 8:30pm.

Thomas Gull, Editor UZH magazin; English translation by Caitlin Stephens, UZH Communications

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