By Sabine Stanley, Ph.D., Johns Hopkins University
If humans do end up spending significant time on the Moon, they will need not only a protective base but also resources. What are the currently available resources on the Moon, and how we can keep an eye on them for the future?
(Image: Dotted Yeti/Shutterstock)
Lava Tubes
There are long, narrow, meandering depressions called sinuous rilles on the Moon that look like a dried-up river. They tend to be found attached to extinct volcanic vents, where the lava would have originated.
We don’t fully understand how these depressions formed, but one theory is that they are lava channels. One of the most photogenic rilles is Hadley Rille, which was chosen for the nearby landing site of Apollo 15. This rille is about 100 kilometers long, a kilometer wide, and about 300 meters deep.
The Apollo 15 crew studied Hadley Rille, took pictures of its walls, and even gathered some samples in the area. They found that outcrops in the walls showed signs of layering or stratification, a sure sign that material flowed through the rilles. Another possible explanation for sinuous rilles is that they are collapsed lava tubes.
Lava tubes are subsurface empty conduits where lava previously flowed through. They may have started as channels, but the surface of the lava channel solidified while the interior stayed liquid, creating a sort of pipe for lava to flow through.
We have lava tubes on Earth too, for example, the Nāhuku lava tube in Hawaii, which is about 500 years old and is big enough for people to comfortably walk through. But lunar lava tubes can be much bigger than their Earthly counterparts because gravity on the Moon is weaker—perhaps hundreds of meters wide and hundreds of kilometers long.
Learn more about humans on the Moon—a never ending story.
Lunar Bases in Uncollapsed Lava Tubes
It’s been suggested that lava tubes that haven’t collapsed may be ideal locations for lunar bases. Here, under the surface, humans would be shielded from radiation and from meteors. This type of protection is particularly important since the Moon doesn’t have an atmosphere that can provide some shielding from small meteors and radiation.
However, the question is, how do you find the uncollapsed lava tubes? That is, the ones that still have their roofs, and so don’t display features like sinuous rilles on the surface. One possibility is to look for skylights or underground tunnels that may have once been filled with lava. These are small places where the roof may have caved in a bit.
For example, we see pit craters in Mare Tranquillitatis that don’t seem to have the right shape for an impact crater. Instead, we seem to be staring into a hole in a pipe, with the bottom of the pit crater about 100 meters down.
This is a transcript from the video series A Field Guide to the Planets. Watch it now, Wondrium.
Water on the Moon
If humans do venture to spend significant time on the Moon, then in addition to a protective base, they’ll also need resources, water being a particularly important one. Without an atmosphere, temperatures on the Moon are directly related to where the Sun is shining. And it can be extreme. Wherever sunlight hits the unprotected surface, the temperature can reach 260°F, so any water would evaporate away; while where the Sun does not strike the surface, the temperature can reach −280°F.
And bear in mind that a day on the Moon lasts about 13 Earth days long, so we don’t expect water, whether liquid or solid, to be found in most places on the lunar surface. But it turns out there is a bit of water on the Moon; you just have to know where to look for it.
First, water ice has been found at the bottom of some permanently shadowed craters in the polar regions, just like Mercury. But we may not have to go to the poles to collect water on the Moon. There is also water locked up in the minerals formed during explosive volcanic eruptions.
So, lunar astronauts may be able to just head over to their local pyroclastic flow deposit to extract some water from the hydrated minerals in these locations. Interestingly, the fact that there is water in these erupted magmas suggests that the deep lunar interior may be quite water-rich.
This is unexpected because the impact forming the Moon involved very high temperatures and a molten Moon in which all of the water should have escaped.
This suggests that water may have been brought to the Moon by comets or asteroids shortly after its formation, perhaps while it was still only partially solidified.
We understand the Moon better than any other object in the solar system. Plate tectonics has destroyed most of the oldest crust on Earth, but the old surface of the Moon has remained, providing a benchmark for dating every other destination in the solar system. This is why returning to the Moon is so important. Every improvement in our understanding of the Moon will cascade through our understanding of every other planet, especially Earth.
Learn more about the Earth and how plate tectonics sets up life.
Common Questions about the Future on the Moon: Lunar Bases
There are no bases on the Moon as of now, but Russia is planning to build a human colony on the Moon by 2030.
A study from the Center for Strategic and International Studies has suggested that a lunar base could cost up to 35 billion dollars to construct and 7.35 billion dollars to maintain.
NASA is planning to send astronauts to the Moon by 2024. They also intend to establish sustainable lunar exploration by 2028.
The main reason we stopped going to the Moon was money. The cost of manned lunar missions was astronomical, especially in comparison to the robotic lunar exploration
