Credit: ZME Science.
A small rock found in the deserts of northwest Africa may actually be a fragment from a moon-shaking blast from 3.5 billion years ago — a time when life was barely beginning to gain a foothold on Earth.
The meteorite, called Northwest Africa 12593, appears to preserve the scars of three separate impacts, including one ancient collision powerful enough to melt part of the lunar surface into a sheet of molten rock.
This is an incredibly rare and scientifically valuable discovery. On Earth, rocks from this deep past are rare because our planet constantly recycles its crust through erosion, burial and plate tectonics. The moon, by contrast, acts more like a battered archive.
The new study, published in Geology, suggests that a major impact struck the moon around the same time as other known impacts on Earth and on Vesta, one of the largest bodies in the asteroid belt. This alignment could help scientists piece together what the inner solar system looked like when Earth was young — and when early life was emerging. If the evidence so far is to be believed, it was pretty rough in our cosmic neighborhood.
A Violent Clue from a Barren World
Earth and the Moon share a violent origin story. The Moon is thought to have formed after a large planetary body struck the young Earth, sending debris into orbit that eventually coalesced into the Moon. That shared beginning makes lunar rocks a rare archive of impacts from a period Earth has largely erased.
Since then, Earth’s surface has changed again and again. But our Moon has no oceans, no plate tectonics and no weather to erase its old scars.
That makes lunar samples extremely valuable time capsules.
“On Earth, the first fossil evidence of life shows up around 3.5 billion years ago, meaning that life is emerging and evolving before then. The question that we often have, even going back further, is what was the impact record when life was emerging?” said Carolyn Crow, a planetary scientist at the University of Colorado Boulder.
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“It is important for understanding how life is taking hold, how life is emerging. The cadence of these catastrophic events is an important part of the equation,” Crow added.
To find that cadence, Crow and her colleagues turned to NWA 12593, a lunar meteorite found in northwest Africa. Using radiometric dating — a method that tracks how radioactive elements decay over time — the team dated the oldest impact recorded in the rock to about 3.5 billion years ago.
That places the event roughly 1 billion years after the solar system formed, when the planets had already taken shape but the solar system was still packed with enough debris to deliver devastating blows. And often.
The Moon Briefly Turned Molten
Four different NAC images of a crater (18 meter diameter) formed on the moon, March 17, 2013; each scene is 560 meters wide. Credit: NASA/GSFC/Arizona State University
The oldest impact recorded in NWA 12593 was not a small crater-forming event. According to the study, it was large enough to melt lunar surface material into a sheet of rock that behaved almost like lava.
The key clue came from cubic zirconia.
You might know of cubic zirconia as a diamond-like gemstone made in laboratories. You often see them in modern jewelry. In a lunar meteorite, it’s like an archive. The mineral forms only at extremely high temperatures, the kind produced when an impact releases enormous energy into rock.
Cubic zirconia does not last once the rock cools to ordinary lunar temperatures. In NWA 12593, the researchers found the next best thing: mineral traces left behind after cubic zirconia broke down and recrystallized. Those traces show that the impact briefly heated lunar rock to temperatures high enough to create the diamond-like mineral in the first place.
In plain terms, the meteorite carries a mineral fingerprint of extreme heat.
The rock also records a second impact. This later collision broke up the ancient melt sheet and helped create a breccia, a rock made from broken fragments fused together.
“Breccias are similar to what you would see if you went and chipped out a chunk of concrete. You would see all these little rocks, and then it’s fused together by the cement,” Crow said. “But the meteorite is fused together by the impact process. You get all these chunks of different kinds of rocks that the impact hit into. These all get mixed up, and then it gets fused together like your concrete sidewalk.”
The third impact came much later. It blasted that chunk of lunar rock off the moon and sent it on a path that eventually crossed Earth.
Three Worlds
The most intriguing part of the finding is not only the moon impact itself. It is the timing.
The 3.5-billion-year-old event lines up with evidence for major impacts on Earth and on Vesta, the fourth-largest object in the asteroid belt. Scientists do not often get matching impact records from three different worlds, especially from such an ancient period.
“It’s not very common, which is why we’re very excited about it,” Crow said. “It’s pretty rare to have all three records line up like this.”
In its first chapter, the solar system was a disk of gas and dust. Small grains stuck together. Driven by gravity, those clumps grew into asteroid-like bodies, then protoplanets, then planets and moons. In that era, collisions were less destructive and more part of the construction process.
But by 3.5 billion years ago, the inner solar system may have been moving out of that constant bombardment phase. Impacts still happened, but they may have come more often from asteroid breakups or unstable leftovers than from the planet-forming chaos itself.
Large impacts could have reshaped coastlines, boiled local seas, altered the atmosphere and damaged early ecosystems. They also may have created new environments where chemistry could flourish. Scientists still debate how impacts helped or hindered early life, but they agree on one point: the timing of those impacts is intriguing and worth investigating further.
NWA 12593 gives researchers one more timestamp.
Meteorites Are Filling Gaps Left by Apollo
A scanning electron microscope image of a piece of the lunar meteorite 16286. The different shades of grey highlight the different minerals in the rock. Credit: Dr Joshua Snape / University of Manchester.
NASA’s Apollo missions, the Soviet Luna missions and China’s Chang’e missions brought back priceless lunar samples, but they came from limited places on the moon. The advantage of meteorites is that they can come from unknown regions, including areas no spacecraft has sampled directly.
A separate lunar meteorite study that appeared in 2025 underscores the point. That meteorite, Northwest Africa 16286, distinct from NWA 12593, is a 311-gram volcanic lunar meteorite found in 2023 and dated to about 2.35 billion years ago.
Apollo, Luna and Chang’e 6 samples mostly span about 3.1 billion to 4.3 billion years ago, while Chang’e 5 returned younger rocks around 1.9 billion years old. NWA 16286 sits between those records and suggests the moon stayed volcanically active longer than scientists once thought.
“Its age and composition show that volcanic activity continued on the moon throughout this timespan, and our analysis suggests an ongoing heat-generation process within the moon, potentially from radiogenic elements decaying and producing heat over a long period,” lead researcher Joshua Snape of the University of Manchester said, according to Space.com.
“Moon rocks are rare, so it’s interesting when we get something that stands out and looks different to everything else,” Snape added.
Together, these meteorites point to a moon that is more than a dead gray ball in the sky. It’s rocks and minerals have kept a record of impacts, volcanism and the changing nature of the solar system.
For NWA 12593, the next step is more analysis. Scientists want to match its record more closely with ancient impact signatures on Earth and Vesta. If those links hold, one desert meteorite may help reveal what exactly was happening across the inner solar system when life on Earth was just beginning to leave its first traces.