“China finds meteorites on the dark side of the Moon that could explain the origin of water, all thanks to a few grams of dust!”
In June 2024, they returned to Earth with just a few grams of dust. What seemed like a routine sample soon revealed a discovery that rewrites part of the history of the solar system. Scientists identified traces of CI meteorite remnants in those tiny particles, an extremely rare variety of carbonaceous chondrites: on Earth, these fragments come from the farthest regions of the solar system, where icy bodies that carry water and organic compounds are born.
### Echoes of an ancient impact
They concluded that the fragments originated from an impact that occurred billions of years ago. A progenitor body collided with the lunar surface, melting part of the soil and trapping chemical traces of its origin in the regolith. While on our planet, erosion and other factors have altered the evidence over time, the Moon, with its lack of atmosphere and erosion, preserves the memory of these impacts intact, like a natural cosmic archive where the imprints of time remain suspended, protected from oblivion.
### Water, carbon, and organic matter
CI chondrites are no ordinary rocks: their discovery on the Moon’s far side suggests that asteroids from the outer regions of the solar system could have impacted the Moon, depositing materials that later gave rise to the water detected on its surface. Researchers also found isotopic signatures of oxygen that match previous studies on lunar water presence, reinforcing the hypothesis that these meteorite impacts were a key source of hydration in the early stages of the solar system. This discovery also offers a clue about how primitive organic matter was distributed among planets and moons through a silent exchange driven by cosmic bombardment over four billion years ago.
### China’s new lunar era
China’s mission marked a milestone as the first to bring samples from the Moon’s far side, a territory never before explored directly by humans. Now, with plans for future lunar scientific stations, China aims not only to explore the Moon but also to understand it and unravel the clues of how our solar system formed.
In those two grams of lunar dust lie billions of years of history. Each particle is a capsule of the past, a fragment of meteorites that traveled from the edges of the solar system, through the void, to settle on the far side of our satellite, where they remained intact for eons. While upcoming missions will continue to unearth secrets, the Moon remains the same silent guardian, orbiting our planet with the calmness of one who knows too much. Sometimes, it just takes a little dust and the patience of billions of years.
