Earth’s earliest chapter is mostly gone.

Rocks from the planet’s first few billion years have been eroded, buried, recycled, or dragged back into the mantle. This has left only scattered traces of the world in which life first appeared. Therefore, every surviving clue is unusually valuable, especially when scientists are trying to answer a basic question. How often did giant impacts strike the young inner solar system while life was beginning on Earth?

A lunar meteorite recovered in northwest Africa is now offering one of those clues. In a study published in Geology, researchers report that the rock records a major impact on the Moon about 3.486 billion years ago. The age closely matches evidence of ancient impacts preserved on Earth. It also matches impact ages tied to 4 Vesta, the fourth-largest object in the asteroid belt.

That rare overlap, the team says, helps connect the histories of three different bodies at a time when the inner solar system was still getting hammered. This happened long after the most chaotic phase of planet formation had passed.

“It is important for understanding how life is taking hold, how life is emerging,” said Carolyn Crow, a planetary scientist at the University of Colorado Boulder. “The cadence of these catastrophic events is an important part of the equation.”

Earth is a difficult place to do deep-time impact archaeology. The oldest undisputed impact record on this planet spans roughly 3.5 billion to 3.2 billion years ago, preserved in ancient ejecta deposits on the Kaapvaal and Pilbara cratons. However, much of the older record has been erased by erosion and subduction, and some ancient structures remain debated.

The Moon offers a cleaner archive. Unlike Earth, it has not been continuously reworked by water and plate tectonics. Even so, the Moon’s own impact history has been contentious. Apollo samples seemed to support a sharp spike in impacts around 3.9 billion years ago, a proposed “late heavy bombardment.” Yet other evidence has suggested that major collisions continued well after that date.

The new meteorite, known as Northwest Africa 12593, adds weight to that longer timeline.

Crow and her co-authors studied slices of the meteorite using electron microscopy, micro X-ray fluorescence, electron backscatter diffraction, and lead isotope measurements. The rock is a fragmental breccia. It is a jumble of broken pieces fused together by impacts.

“Breccias are similar to what you would see if you went and chipped out a chunk of concrete,” Crow said. “You would see all these little rocks, and then it’s fused together by the cement.”

“But the meteorite is fused together by the impact process,” she added. “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.”

Inside NWA 12593, the team found signs of three separate impact events.

The oldest was the most dramatic. Tiny grains of baddeleyite preserved what the authors call cubic zirconia phase heritage, a structural trace showing that the mineral had once existed in a high-temperature cubic form. That matters because cubic zirconia forms only at extreme temperatures, above roughly 2,370 degrees Celsius. These conditions are consistent with superheated impact melt.

In everyday life, cubic zirconia is best known as a manufactured gemstone. But outside tightly controlled lab conditions, it does not remain stable as temperatures fall. In the meteorite, the researchers identified its mineralogical fingerprint rather than intact low-temperature crystals.

That fingerprint, combined with the character of the rock, points to a large lunar impact powerful enough to generate a melt sheet. This is a broad layer of molten material spread across the surface. The team dated that event to 3486 ± 10 million years ago using uranium-lead isotopes in baddeleyite grains.

The second event came later, when a smaller impact broke up that earlier melt sheet and helped form the breccia now seen in the meteorite. The third was still more recent. Another collision blasted the rock off the Moon and eventually sent it to Earth.

The researchers argue that the 3.486-billion-year age records the original high-temperature crystallization of material from the earlier impact, not later disturbance. The grains remained crystalline and showed little sign of alteration. They also lacked evidence that the later breccia-forming event heated them enough to reset the isotopic clock.

What makes the result stand out is not just the lunar date by itself. It is the company that date keeps.

The Moon age lines up with terrestrial spherule beds dated to about 3.5 billion years ago and with impact ages from eucrite meteorites tied to 4 Vesta. According to the paper, that makes Earth, the Moon, and Vesta three separate bodies preserving evidence of near-synchronous large crater-forming impacts at about the same time.

“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.”

The distances involved make the match especially striking. These bodies occupy very different parts of the inner solar system. Yet their records appear to reflect the same broad interval of continued bombardment between about 3.7 billion and 3.2 billion years ago.

That pushes against the idea that the main story ended near 3.9 billion years ago.

The authors describe the new age as “unequivocal evidence” for prolonged bombardment after the basin-forming epoch. Their broader compilation of Earth, Moon, and Vesta impact ages from 3.8 billion to 3.0 billion years ago also shows peaks around 3.7 billion years, 3.5 billion years, and 3.2 billion years.

The timing overlaps with an important threshold on Earth. Fossil evidence places life on the planet by about 3.5 billion years ago. This means some of these large impacts were happening while the earliest biosphere was taking shape.

That does not mean the impacts simply destroyed emerging life. The paper notes that bombardment during this interval has been proposed as a way to deliver critical amino acids and generate hydrothermal environments that could support cellular life. Additionally, other researchers have also suggested that impacts may have influenced deeper planetary processes, including the onset of subduction through heating of the mantle.

The new study does not prove those links. What it does provide is a firmer timestamp from the Moon. This strengthens the case that Earth’s oldest impact deposits are not isolated oddities but part of a broader inner solar system pattern.

For a planet that has erased much of its own youth, that matters.

The Moon is not just a companion in the sky, it is also a backup archive.

This work gives scientists a new anchor point for reconstructing conditions in the inner solar system when Earth was becoming habitable. Life had either emerged or was close to doing so at that time.

A better impact timeline can help researchers test ideas about how often giant collisions reshaped planetary surfaces. It can also help them assess how long heavy bombardment lasted after 3.9 billion years ago. Moreover, it can help determine whether those impacts contributed to environments that supported early life.

It also sharpens the value of lunar meteorites as a stand-in record for parts of Earth history that this planet no longer preserves.

Research findings are available online in the journal Geology.