The ancient history of our planet’s impact events is coming into focus, thanks to researchers who have triangulated similarly aged impacts on Earth, the Moon, and the asteroid 4 Vesta in a new study.

The lunar meteorite NWA 12593 correlates not only with impact events observed across three locations in our solar system but also contains evidence of three separate impact events that occurred at different times.

The findings, revealed in a recent paper published in Geology, show that scientists are using this new impact data to fill in the volatile early-Earth period when life began.

Early Earth Impacts

The Archean period, roughly 4 to 2.5 billion years ago, was a consequential time from which our earliest fossil records date, corresponding to around 3.5 billion years ago. Researchers believe that life likely first arose at this time, yet it may have faced adversity from bombardment by space rocks between 3.2 and 3.5 billion years ago, although scientists disagree on how intense this impact activity was.

Our planet’s geological activity eventually destroys evidence of the ancient past through erosion, subduction, and burial, continually reshaping the surface. Yet those early years are essential to understanding the origins of water, atmospheres, and life on Earth. 

“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 lead author Carolyn Crow, a planetary scientist at the University of Colorado Boulder.

“It is important for understanding how life is taking hold, how life is emerging,” Crow added. “The cadence of these catastrophic events is an important part of the equation.”

A Neighbor Remembers

While Earth’s surface is constantly renewed by geological processes, our nearest significant neighbor, the Moon, is much more stable, retaining its geological record for longer periods. Because of this, lunar meteorites provide a resource for scientists to understand the impact of Earth and the inner solar system by matching them to known impacts on our planet and in the asteroid belt.

For the recent study, the team focused on a lunar meteorite discovered in northwest Africa, designated NWA 12593, and identified three separate impact events in a single sample. 

Radiometric dating traced the oldest to 3.5 million years ago, intriguingly close to the time of the earliest known fossils. Extraordinary in power, this impact produced the mineral zirconia by melting the lunar surface into a lava-like flow. Without the precise laboratory conditions required to produce stable cubic zirconia, only traces of mineral remained in the sample.

According to the team, the first impact aligns with previously known impact events on Earth, and the fourth-largest object in the asteroid belt, 4 Vesta. It’s extremely rare to find such corresponding evidence between three bodies, providing important data on this time of frequent collisions.

“It’s not very common, which is why we’re very excited about it,” says Crow. “It’s pretty rare to have all three records line up like this.”

Later Impacts

Evidence of later impacts included breccia composed of large, angular, broken mineral fragments cemented together. The team believes the breccia resulted from a second impact that struck the melt sheet formed by the first.

“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,” says Crow. “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.”

As for the third impact, the evidence for this is the meteorite’s mere presence on Earth; an event that occurred some time after the first would have ejected the lunar breccia, the researchers say, allowing it to eventually land on our planet.

In total, the sample reveals an intriguing impact history, preserving a record of bombardment that provides solid evidence for a flurry of activity in the inner solar system during a violent chapter in the early history of our Solar System.

The paper, “Three-Body Evidence of Ca. 3.7 Ga to 3.2 Ga Bombardment Across the Inner Solar System,” appeared in Geology on May 12, 2026.

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.

An unexpected human behavioral tendency to prefer turning counterclockwise rather than clockwise has been uncovered by a team of researchers in Spain and Japan, and its cause remains unknown.

In a recent paper published in Nature Communications, the team sought to identify patterns in individual human behavior among large crowds and determine which factors influence them. Surprisingly, the team found that counterclockwise turning is the overwhelmingly common behavioral preference, regardless of gender or culture, with only age making a slight difference.

An Unexpected Behavior

The team’s work could have ramifications not only for psychology but also for architecture, engineering, and design, enabling more intuitive layouts. Work on the project began at Spain’s University of Navarra, before experiments continued at the University of Tokyo in Japan.

The University of Navarra team discovered the phenomenon entirely by accident while researching social distancing during the COVID-19 pandemic. Initially, their interest was in monitoring how effectively the recommended six-foot spacing could be maintained in public spaces. They observed how humans moved through spaces, such as museums, without a set route. While closely monitoring crowd video, they were surprised to witness the counterclockwise trend emerge.

“When analyzing the experiments, my colleagues realized by chance that in 32 out of 33 experimental trials, as people moved and turned, they noticeably preferred to turn counterclockwise,” said co-author Professor Claudio Feliciani from the University of Tokyo’s Department of Aeronautics and Astronautics.

“This was completely unexpected as, at least instinctively, when people walk around randomly, you imagine people turn as their needs suit them with little sign of an overall preference,” Feliciani added. “But there was a definite, measurable tendency for people to turn counterclockwise over clockwise, all things being equal.”

Exploring Internationally

With their curiosity piqued, the University of Navarro team sought to test their findings against further observations to determine which factors might be influencing the behavior. They decided to seek international follow-up observations. This brought them into contact with Claudio Feliciani, whose presence in Tokyo would allow the project to test how the trend played out across cultures, and among other factors. 

For the second stage of the project, Feliciani and his team developed a series of experiments targeting age, handedness, gender, group size, and cultural influence. They observed pedestrian test subjects in both constrained and open environments.

“Of all these things, the only thing that stood out was that kids tend to have a stronger bias for the counterclockwise direction, so probably age plays a role in making the effect weaker or stronger,” said Feliciani. “Our results may appear as a minor, insignificant discovery, but in nature, most phenomena related to locomotion show that animals mostly walk without directional preference.”

“The strong bias found in people hints to some asymmetry at the biomechanical level,” Feliciani added.

Unknown Behavioral Causes

With the international project having confirmed the counterclockwise trend, the researchers are now moving on to more granular exploration of the phenomenon at the individual level. They hope that this more individualized research will yield some information on what biomechanical factors may be driving the behavior.

“It likely does not come from the eyes, because we tried to patch people’s left or the right eyes and the bias was still there,” Feliciani said. “And some people asked us if it might be large-scale phenomena like the Coriolis force or Earth’s magnetic field, but this seems unlikely given what we have managed to point to so far. “

Both lead investigator Iñaki Echeverría Huarte and Feliciani say that the Coriolis effect has become something of a joke among the team, and that they are invariably asked about it when presenting their findings.

“As a curious aside, a friend and collaborator in Argentina was intrigued enough to run some similar experiments when he heard about this,” Huarte told The Debrief of the team’s research in an email. “He tells me that, with no proper scientific confirmation yet, the counterclockwise rotation still seems to be there in the southern hemisphere too.

“There are some interesting parallels to certain sports,” Feliciani concluded. “Some running and driving competitions are always, but inexplicably, taken on courses that run counterclockwise. But that’s an investigation for another time.”

The paper, “Individual Locomotor Bias Drives Counterclockwise Motion in Pedestrian Crowds,” appeared in Nature Communications on June 10, 2026.

Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.