Chang'e-6 Reveals Unexpected Resurgence in Moon's Ancient Field

A New Chapter

The Chang'e-6 lunar mission has brought back a wealth of information about the Moon's history, including a surprising discovery about its magnetic field. Rock samples collected from the far side of the Moon indicate that the lunar magnetic field experienced a resurgence in strength around 2.8 billion years ago. This finding challenges previous assumptions based on data from the Apollo missions, which suggested a steady decline in the Moon's magnetic field since its formation.

The analysis of these samples, published in the journal Nature, marks the first-ever paleomagnetic data obtained from the Moon's far side. This data provides crucial insights into the intermediate evolutionary stages of the lunar dynamo, the mechanism that generated the Moon's magnetic field in the past.

The Earth's magnetic field acts as a protective shield, safeguarding the planet from harmful cosmic rays and preserving essential elements for life, such as the atmosphere and water. The Moon once possessed a similar magnetic field, but it ceased functioning long ago. Studies based on samples from the Apollo missions indicated that the Moon's magnetic field was relatively active between 4.2 billion and 3.5 billion years ago, but then declined significantly around 3.1 billion years ago.

The Chang'e-6 mission has provided an unprecedented opportunity to study the Moon's magnetic field evolution. The samples collected from the far side of the Moon, with an eruption age of 2.8 billion years, reveal a higher ancient magnetic field strength than previously thought. This suggests that after a sharp decline 3.1 billion years ago, the lunar magnetic field may have experienced a rebound or reactivation around 2.8 billion years ago.

This unexpected finding raises questions about the mechanisms driving the lunar dynamo. Researchers speculate that the resurgence could be due to a change in the main energy source of the dynamo or a reinforcement of its initial driving mechanism.

The Chang'e-6 mission's findings not only provide the first direct information about the ancient magnetic field on the Moon's far side but also offer crucial clues to understanding the evolution of the Moon's magnetic field. This new knowledge will help us piece together the complex history of our celestial neighbor and its role in the solar system.