An anonymous reader quotes a report from The Verge: New research shows that oxygen from Earth could be journeying all the way out to the Moon, where it then gets lodged inside the lunar soil. It’s a process that’s likely been happening for 2.4 billion years, ever since oxygen formed around our planet, meaning the Moon’s soil may contain trapped particles from Earth’s ancient atmosphere. This oxygen exchange, detailed in a study published today in Nature Astronomy, supposedly occurs for just a few days during the Moon’s 27-day orbit. Most of the time, the Moon is constantly being blasted with solar wind — fast streams of charged particles emanating from the Sun. But for five days of every lunar orbit, the Moon passes into Earth’s magnetotail, the portion of the planet’s magnetic field that stretches outward away from the Sun. This tail shields the Moon from the solar wind, and allows charged oxygen ions from Earth to travel to the lunar surface, according to the study. That means the Moon — a dead rock incapable of supporting life — is being showered with the byproducts of life here on Earth. In fact, the source of most of the oxygen in our atmosphere is biological, created by plants during photosynthesis. It’s a process that experts have suspected for a while but haven’t been able to confirm until today. Researchers have also suggested that other atmospheric components, such as nitrogen and noble gases, are getting to the Moon this way based on lunar soil samples.
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