If you were transported to the moon at the same time, you would surely die quickly. This is because there is no atmosphere, the surface temperature ranges from baking 130 degrees Celsius (266 F) to cooling the bone minus 170 C (minus 274 F). If the lack of air, terrifying heat or cold will not kill you, then a micrometeorite bombardment or solar radiation will occur. In every respect, the Moon is not a guest place.
However, if people are to explore the Moon and potentially live there one day, we will have to learn to deal with these difficult environmental conditions. We will need habitats, air, food and energy, as well as fuel to propel rockets to Earth and possibly other destinations. This means that we will need resources to meet these requirements. We can either take them with us from Earth – an expensive proposition – or we will have to use resources on the moon itself. And here comes the idea of "using resources in situ" or ISRU.
At the heart of efforts to use lunar materials is the desire to establish temporary or even permanent human settlements on the moon – and that's a lot of benefits. For example, lunar bases or colonies can provide invaluable training and preparation for missions in remote locations, including Mars. The development and use of lunar resources will probably lead to a huge number of innovative and exotic technologies that can be useful on Earth, as was the case with the International Space Station.
As a planetary geologist, I am fascinated by how other worlds were created and what lessons we can learn about the formation and evolution of our own planet. And because one day I hope to visit the Moon personally, I am particularly interested in how we can use resources to make exploration of the solar system as economical as possible.
Using resources on site
ISRU sounds like science fiction and for now it is largely the case. This concept involves identifying, extracting and processing material from the surface of the moon and interior, and transforming it into something useful: breathing oxygen, electricity, building materials, and even rocket fuel.
Many countries have expressed a renewed desire to return to the moon. NASA has many plans for this, in January China has landed a rover on the lunar front and now has an active rover, and many other countries have in mind moon missions. The necessity of using materials already present on the moon becomes more urgent.
Predicting lunar life is the engine of engineering and experimental work to determine how to effectively use lunar materials to support human exploration. For example, the European Space Agency plans to land a spacecraft at the Lunar South Pole in 2022, to drill under the surface in search of water ice and other chemicals. This vessel will be equipped with a research instrument for harvesting water from lunar soil or regolith.
Even the final extraction and bringing to Earth a helium-3 enclosed in the lunar regolith was even discussed. Hel-3 (a non-radioactive helium isotope) can be used as a fuel in fusion reactors to produce huge amounts of energy at very low environmental costs – although nuclear fusion has not yet been demonstrated and the volume of extractable helium 3 is unknown. Nevertheless, while the real costs and benefits of lunar ISRU remain visible, there is no reason to believe that significant interest in lunar extraction will not continue.
It is worth noting that the Moon may not be a particularly suitable place for mining other valuable metals such as gold, platinum or rare earth elements. This is due to the differentiation process in which relatively heavy materials drown and lighter materials rise when the planetary body is partially or almost completely melted.
Basically, this happens if you shake the test tube filled with sand and water. First everything mixes with each other, but the sand eventually separates from the liquid and falls to the bottom of the pipe. And as in the case of Earth, most of the Moon's resources of heavy and valuable metals are probably deep in the mantle, and even in the core, where they can not be accessed. Indeed, it is because small bodies, such as asteroids, generally do not undergo differentiation because they are such promising targets in the search and mining of minerals.
Indeed, the Moon occupies a special place in planetary science because it is the only other body in the Solar System in which people set foot. The NASA Apollo program in the sixties and seventies brought a total of 12 astronauts walking, bouncing and moving around the surface. The samples of the rocks they brought and the experiments they left there made it possible to better understand not only our Moon, but also how planets are generated than would otherwise be possible.
Of these missions and others over the next decades, scientists have learned a lot about the moon. Instead of growing out of the cloud of dust and ice, as the planets in the solar system did, we discovered that our nearest neighbor is probably the result of a massive impact of the proto-Earth and the object of the size of Mars. This collision ejected a huge amount of debris, some of which later merged into the Moon. From the analysis of lunar samples, advanced computer modeling and comparisons with other planets in the solar system, we have learned many other things that colossal impacts can be the rule, not the exception in the early days of this and other planetary systems.
Conducting scientific research on the Moon would dramatically increase our knowledge of how our natural satellite was created and what processes work on the surface and inside it to make it look the way it looks.
The coming decades promise a new era of moon exploration, in which people live there for a long time, thanks to the extraction and use of the natural resources of the moon. Thanks to constant, determined effort, the Moon can become not only a home for future explorers, but also a great milestone, from which we can make another gigantic leap.
Paul K. Byrne, assistant professor of planetary geology, State University of North Carolina
This article is republished with The Conversation under a Creative Commons license. Read the original article.