ARLIN CROTTS, author of The New Moon: Water, Exploration, and Future Habitation, shares his latest findings about our closest astronomical neighbor with Fairweather's ANETA JEDLICKA
Aneta Jedlicka: How did you initially become interested in space?
Arlin Crotts: I was born a year after Sputnik won, so it was hard not to be interested in
space. They called us the Sputnik babies.
AJ: Please tell us about your research on the Moon. What have you found?
AC: Well I am interested in the presence and production of the light elements. So, Hydrogen, Water, Sulfur dioxide, as well as gases that are produced by radioactive decay like Helium and Argon, so basically all the things that the Moon was not supposed to have. When it comes to the Moon, the model throughout history was that the Moon was heated up to high temperatures so all of those elements should have boiled off, but it seems like that is not the story any more. In terms of results I wrote a few papers a few years ago, back before people started finding all these signs of water, and I said the evidence isn’t so clear that you shouldn’t find water on the Moon, as well as the idea that the Moon isn’t producing gas. I concluded this by finding some additional evidence for this phenomenon, called the lunar transience, which are little lights that appear on the Moon and usually take a few minutes to go away.
People have been observing them for over 100 years, basically since the invention of the telescope. They oversee some little area that corresponds to a few 100 km across, and it will light up and turn fuzzy and after a few minutes it will go away. There are these 6 different sights where people keep seeing these lights. So the way these lights got investigated was by having a spacecraft orbit the Moon with an alpha particle spectrometer on it and quite often it turned out that the sensors would come over some part of the Moon and suddenly start sensing alpha particles from radon gas on the Moon surface. We could further conclude that there is this pool of gas sitting on the surface of the Moon, being this very heavy gas, therefore not being able to immediately evaporate into space. The surprising thing about that is that these are the same group of sights where people consistently see these little lights. I don’t think that is a random coincidence.
AJ: What startling discoveries are being uncovered on the Moon?
AC: In my papers, I found that there is some sort of gas coming out of the Moon in these episodes, which corresponds to where ice should be found in the lunar soil. Specifically, in the polar areas of the Moon. The evidence is just getting stronger. In 2007 people reanalyzed the Apollo samples, which are little glass beads that you find in the soil that have been thrown out as a volcanic eruption. So when gas mixes with lava and comes up to the vacuum, the gas is going to come out of solution. Resulting in a very frothy and explosive lava flow, called a fire fountain. Which is basically just the lava exploding out of the ground with little droplets of lava flying through space. When flying through space they have time to cool, so they just rain down as tiny little glass beads. The samples brought back a few different classes of these glass beads and what they found is that inside them is a large amount of water and sulfur dioxide. Therefore, it really seems that water is actually really important as a constituent in this ancient lunar lava, which drives these explosive eruptions out of the ground.
Now researchers made models of this, which say that as the Moon cools down the water collects in a layer right below the lunar crust and all we have to do is dig 40 km into the lunar crust and that is where we can see it. What I pointed out is that the top 10 meters is lunar soil, which is ground up dust and rock from all the lunar impacts that have occurred over the past millions of years. So if you have water as one of the main constituents its not going to make it out, it’s going to actually freeze in place and sit there for billions of years. That is exactly what I am trying to find out about now, because it is very important scientifically, as well as if we were ever to go to the Moon to try to find water, this would be a very good place to look.
We already know there is water on the Moon since 2009. We have found deposits of water on the Moon, which amount to a billion tons and that is an amazing amount of water by human standards. Since water is made of oxygen and hydrogen and both of those in liquids are one of the best rocket fuels you can get, there is basically a billion tons of rocket fuel sitting in a reasonably confined space on the Moon. We could launch a space shuttle every day for about 2200 years with that fuel. You can get rocket fuel on the Earth, but to get it out of space you have to get it out of the clutches of the Earth's gravitational field and to send a few humans to the Moon you would have to have a rocket that is 120 meters tall, which throws out 95% of that just getting out of Earth's gravitational field. In order to get off the surface of the Moon the energy is 1/30th.
We basically have a potential of a petrol station out in space, in which we would not have to get the fuel up to the Moon we could just use that fuel in and around the Moon to go to Mars. It is sort of like an amazingly valuable resource, and one suggestion that I have in my book is that you could make a lot of money off of this right now. Even though it is 400 hundred thousand miles away, in terms of energy it is only right there. So if you were making fuel on the Moon you could use that to go into the rest of the geosynchronous orbit.
AJ: What do you see as the first steps humans have to take to enforce human
life on the Moon?
AC: I have this concept to have a lunar-to-Earth space tug and its main job would be to put satellites in place. This would make a huge profit: billions of dollars a year. The research that I am doing now talks about the ice that is below a few meters in the surface and is protected by the thick layer of soil over the top. We know how to work machines and even fly airplanes in the freezing conditions on the Moon so we would not have to invent completely new technology. Therefore, it is important to find out if there is ice a little further into the soil. The Moon is like the Earth; the further you get into the soil the warmer it gets and so finding a warmer place where ice is deposited is a good idea in terms of trying to exploit it.
AJ: Could the Moon become habitable for humans?
AC: Where the water is, is the most important question and I think a lot of people, now that it is after 2009, would agree with me. Along with the scientific questions, I am not advocating that we should send humans out to the Moon right away. I think a lot of these questions can be answered with robotics. The very special thing about the Moon is that it is only a 3 second round trip for radio or light communications.
The Moon is probably the best place to make a living environment. People say that with all the radiation from the Sun, all the meteorites, and the shifting temperatures how could that possibly be a good place to live? However, if you go into the soil a meter or two all those variables go away. So if you want to live some place on the Moon, you would just have to get beneath a relatively small layer of soil.
If we don’t want to dig through the soil, we have also discovered that there are these sorts of caverns on the Moon that we never knew about before and just learnt about in the last few years. They seem to be almost ready for us to move in. Because they are so huge, you could talk about millions of people living in this space without having a huge energy requirement to keep them alive. 45% of the soil is oxygen so it is not like generating oxygen would be too hard.
AJ: How can exploring the Moon benefit development on Earth?
AC: The Moon can serve as an outpost to move beyond and among the Moon. It would be cheaper and more efficient if we used the Moon as our first base. The main thing is we haven’t really explored the Moon; we have only put 20 people on the surface. For a few million dollars the next time we make a satellite land on the Moon, we could just attach a little robot that would listen to commands from the Earth’s surface in order to explore the newly discovered caverns.
AJ: How does new technology allow you to study aspects of space that were not possible before?
AC: What I will talk about is what we need that we don’t have now to explore the
Moon. Which is a sort of more rapid response from robotics. What we are going to need to do is start exploring telerobotics, which are robots that are controlled remotely by people on Earth. Then, we will have to figure out how to make robots that can do the same sort of thing, but more and more by themselves. That is what the whole economy will be asking for eventually.
AJ: Are you excited about the future of space travel?
AC: The Moon has always been side tracked for reasons that never really made sense. The Moon is the only place that is not so incredibly far away. It is always 100 times closer than Mars and a lot of the issues that we will have to figure out to operate on the Moon also apply to things that we will have to figure out to get to Mars. After all, it only takes 3 days to get to the Moon and if a mistake happens you can always come back in 3 days. Therefore, we first have to figure everything out on the Moon until we go further in space to avoid any major mistakes from occurring.
To learn more about ARLIN CROTTS' discoveries, order The New Moon: Water, Exploration, and Future Habitation on amazon.com