Nov 11, 2021 19:00:00

There is enough oxygen on the surface of the moon to survive about 8 billion people for 100,000 years

As NASA and others are proceeding with the Artemis program aiming for a manned lunar landing, methods such as extracting oxygen necessary for astronauts' breathing from the lunar surface are being sought. You may be wondering, 'Is there so much oxygen in the moon when there is almost no atmosphere?', But Dr. John Grant , a lecturer at the Faculty of Science and Engineering at Southern Cross University in Australia, said, 'On the surface of the moon. It contains enough oxygen for the entire population of the planet to survive for 100,000 years. '

The Moon's top layer alone has enough oxygen to sustain 8 billion people for 100,000 years
https://theconversation.com/the-moons-top-layer-alone-has-enough-oxygen-to-sustain-8-billion-people-for-100-000-years-170013

One of the major topics in space development in recent years is ' In-Situ Resource Utilization (ISRU) ', which makes effective use of local resources. Since it costs a lot of money to launch a spacecraft against gravity, it is an attempt to reduce the launch weight by utilizing local resources instead of bringing all the necessary resources from the earth.

Among ISRUs, 'local procurement of oxygen required for fuel and breathing' is especially important. Already NASA is, of Mars spacecraft parser via lance oxygen generator mounted on the ' MOXIE using', the carbon dioxide contained in the atmosphere of Mars to electrolysis to experiment to generate oxygen success has been.

In addition, a method for extracting oxygen from the lunar surface is also being sought. In January 2020, a dedicated experimental facility was opened at the European Space Technology Research Center (ESTEC), and in October 2021, 'Oxygen extraction' NASA and the Australian Space Agency (ASA) have agreed to send an Australian-made rover to test the technology on the moon.

However, the very thin moon's atmosphere does not contain enough oxygen compared to Mars, which has a low oxygen concentration but a rich atmosphere. Therefore, researchers are trying to solve the problem by extracting oxygen trapped in the regolith that accumulates on the surface of the moon.

Dr. Grant said, 'Oxygen is contained in many minerals in the ground around us, and the moon is made of rocks that are almost the same as the earth, although there are slightly more substances derived from silica than the earth. 'Minerals such as silica, aluminum, iron, and magnesium oxide make up most of the lunar landscape. All of these minerals contain oxygen, but they are not available to our lungs.' It states. These minerals, which exist as regoliths on the surface of the moon, are said to be

composed of oxygen atoms in nearly 45% of their weight.

On the earth, in order to separate unnecessary oxygen from alumina (aluminum oxide) in the production of aluminum and the like, electrolysis is performed to separate oxygen atoms by applying a voltage to the molten aluminum oxide. Using this same principle, the Moon can electrolyze minerals to extract oxygen as the main product, Dr. Grant said. In the moon, minerals after oxygen separation are also potentially useful by-products.

Dedicated equipment is required to electrolyze oxygen from the regolith, and the process of heating the regolith into a liquid requires a lot of energy. In early 2021, Belgian startup Space Applications Services announced that it would build three experimental reactors to improve the oxygen extraction process, as well as applying this technology to the European Space Agency 's ISRU mission. As part of this, we plan to send it to the moon by 2025.

Dr. Grant argues that if we can actually extract oxygen from the lunar regolith, we will have a lot of oxygen. An average of 1.4 tonnes of minerals are contained in 1 m ³ of regolith, of which 630 kg is oxygen. One person needs 800g of oxygen a day to survive, so ^{if oxygen can be extracted from 1m 3} of regolith, one person can live for about two years.

Furthermore, assuming that the average depth of the regolith on the moon is about 10 m and oxygen can be extracted from all of them, enough oxygen is available to save about 8 billion people, the total population of the earth, for 100,000 years. And that. 'This also depends on how effectively oxygen is extracted and used. Anyway, this number is great!', Dr. Grant said.