Before the Moon's magnetic field completely disappeared, something boosted it. Here's what scientists discovered.

Researchers have examined soil samples brought back to Earth by the Chinese missions "Chang'e-5" and "Chang'e-6," leading to a significant discovery. It turns out that the Moon's magnetic field existed for approximately 200 million years longer than previously thought. The reasons behind this phenomenon are not entirely clear, but there are some hypotheses. The study has been published in the journal Science Advances, as reported by Interesting Engineering.

Currently, scientists believe that for about 1.5 billion years after the Moon's formation, it possessed a magnetic field as strong as Earth's. It is estimated that its strength fluctuated between 25 and 65 microteslas.

The Moon currently lacks a magnetic field, and it was believed that it began to weaken and disappeared around 3 billion years ago. However, the analysis of lunar soil samples returned by the two Chinese missions indicates that the Moon's magnetic field existed for a longer period and that certain processes may have contributed to its strengthening.

Previous research indicated that approximately 3.1 billion years ago, the Moon's magnetic field began to lose its strength rapidly and vanished within a few tens of millions of years. New data reveals that the magnetic field intensified and managed to persist for several hundred million more years. This means that scientists have found evidence of a magnetic field existing in the rock formations as far back as 2.8 billion years ago. However, this magnetic field had a strength ranging from 5 to 21 microteslas, indicating it was still weak, and only after this strengthening did it completely disappear.

Scientists believe that certain internal processes may have led to both the unexpected strengthening of the Moon's magnetic field and its complete disappearance. The study suggests that the re-establishment of a weak yet stable magnetic field on the Moon around 3 billion years ago could have been triggered by processes such as the crystallization of the Moon's core or the interaction between the core and the mantle. These processes likely sustained the Moon's magnetic dynamo for billions of years.

Additionally, researchers think that the prolonged existence of the Moon's magnetic field may have better protected its surface from intense solar radiation, which helped preserve volatile compounds like water on its surface. This deeper understanding of the Moon's magnetic history provides important insights into its evolution.