Although the Moon does have an atmosphere, it is very thin and mostly made of hydrogen, neon, and argon. This is not a gaseous combination capable of supporting oxygen-dependent animals such as humans.
On the Moon, there is an abundance of oxygen. It is just not in a gaseous state. Rather than that, it is trapped inside regolith — the lunar surface's covering of rock and fine dust. Would oxygen extracted from regolith be sufficient to sustain human life on the Moon?
Oxygen is present in a wide variety of minerals found in the earth around us. Additionally, the Moon is composed mostly of the same materials found on Earth (although with a slightly greater amount of material that came from meteors).
The Moon's surface is dominated by minerals such as silica, aluminum, iron, and magnesium oxides. All of these minerals include oxygen, but in an inaccessible form to our lungs.
These minerals occur in a variety of forms on the Moon, including hard rock, dust, gravel, and stones that blanket the surface. This substance is the consequence of countless millennia of meteorites colliding with the lunar surface.
The regolith of the Moon is composed of around 45 percent oxygen. However, that oxygen is inextricably linked to the minerals listed above. To dismantle such tenacious relationships, we must invest energy.
If you are acquainted with electrolysis, you may be familiar with this. This procedure is often used in manufacturing on Earth, for example, to manufacture aluminum. To separate the aluminum from the oxygen, an electrical current is conducted through a liquid form of aluminum oxide (usually termed alumina) through electrodes.
As a byproduct, oxygen is created in this situation. On the Moon, the primary product would be oxygen, but aluminum (or other metal) would be a potentially valuable byproduct.
It's a rather basic operation, but there is a catch: it consumes a lot of energy. To be sustainable, it would need to be powered by solar energy or other Moon-based energy sources.
Earlier this year, Belgian firm Space Applications Services announced the construction of three experimental reactors to enhance the electrolysis process for producing oxygen. They want to launch the device to the Moon in 2025 as part of the European Space Agency's in-situ resource utilization (ISRU) program.
Having said that, how much oxygen may the Moon supply if we succeed? As it turns out, quite a bit.
We can make some estimations if we disregard oxygen trapped in the Moon's subsurface hard rock material and focus only on the regolith that is readily accessible on the surface.
Lunar regolith includes an average of 1.4 tonnes of minerals, including around 630 kilos of oxygen per cubic metre (35 sq ft). According to NASA, people need around 800 grams of oxygen every day to exist. Thus, 630 kg of oxygen would sustain a human for around two years (or just over).
Assume now that the average depth of regolith on the Moon is around 10 meters and that we can extract all of the oxygen from it. That indicates that the top ten meters of the Moon's surface would contain enough oxygen to sustain the Earth's eight billion people for around 100,000 years.
This would also rely on our ability to collect and use oxygen properly. Regardless, this figurine is rather incredible!
Having said that, we on Earth really have it pretty well. And we should do everything possible to conserve the blue world — particularly its soil — which sustains all terrestrial life without our intervention.