Rock samples collected from the moon's far side by China's Chang'e-6 lunar probe have provided groundbreaking insights into the evolution of the lunar body's magnetic field.

Analysis of the samples, published on Thursday in the journal Nature, indicates the unexpected resurgence in strength of the moon's magnetic field 2.8 billion years ago, following a sharp decline around 3.1 billion years ago. The find challenges the prevailing theory that the moon's lunar dynamo remained in a low-energy state after that decline.

It marks the first-ever paleomagnetic data obtained from the moon's far side, and provides critical insights into the intermediate stages of the evolution of the lunar dynamo, the geophysical mechanism that generated the moon's magnetic field in the past.

On June 25 this year, the Chang'e-6 lunar probe returned to Earth with 1,935.3 grams of lunar samples collected from the previously unexplored far side of the moon.