Scientists uncover massive asteroid impact on the Moon 3.5 billion years ago

The findings, published in the journal Geology, are based on the analysis of a lunar meteorite known as NWA 12593, which was discovered in northwest Africa. Researchers say the rock preserves a record of multiple impact events, including one powerful enough to melt part of the Moon's surface.

Using radiometric dating techniques, the team determined that the earliest impact recorded in the meteorite occurred about 3.5 billion years ago. The collision generated extremely high temperatures, transforming the lunar surface into a vast sheet of molten material. It also produced cubic zirconia, a mineral that forms only under intense heat.

Although cubic zirconia is commonly manufactured for jewelry, naturally occurring traces of the mineral are rarely preserved. Researchers were able to identify remnants of what they describe as a "cubic zirconia phase heritage" within the meteorite, providing evidence of the ancient impact.

The meteorite also records two later events. A subsequent collision shattered the original melt sheet and created a type of rock known as breccia, which consists of fragments of different rocks fused together by impact processes. Much later, another impact ejected the rock from the Moon and sent it on a trajectory toward Earth, where it eventually landed.

According to the research team, the age of the earliest impact closely matches the timing of known impact events previously identified on Earth and on Vesta, the fourth-largest asteroid in the asteroid belt. Such alignment across three different bodies in the solar system is considered unusual.

The discovery provides new evidence linking impact histories across the inner solar system during a period when frequent collisions associated with planetary formation were giving way to less common impacts caused by the breakup of asteroids.

Researchers say understanding the frequency of these ancient catastrophic events is important because the period overlaps with the emergence of early life on Earth. The oldest fossil evidence of life dates to roughly 3.5 billion years ago, making asteroid impacts a key factor in reconstructing the environment in which life first developed.

Unlike Earth, the Moon preserves ancient impact records, allowing scientists to use lunar samples as a window into the early evolution of the solar system.

Earlier, Qazinform News Agency reported that ice had been slowly building up at the Moon's poles for at least 1.5 billion years.