Stanford University scientists say experiments on ancient Chinese stone tools, including 15,000-year-old hand axes, have solved a longstanding mystery about the critical technological transition from rudimentary hand tools to more versatile ground-edged tools, suggesting these new technologies enabled uses beyond food harvesting.

The research team behind the new analysis said the discovery of ground-edged sickles and knives in Neolithic North China, likely used for fiber production and harvesting, combined with their replica-based experiments, highlights the growing technological capabilities of the transition between Paleolithic and Neolithic peoples.

“The combined experimental and archaeological evidence from the site of Peiligang indicates that the emergence of ground-edged tools marked a significant step in technological specialization from the Late Pleistocene to the Early Holocene,” the researchers write in a paper detailing the work.

Mysterious Technological Transition Hidden in 15,000-Year-Old Stone Tools

According to lead author Ran Chen and colleagues, archaeologists widely regard ground-edged cutting tools like the modern sickle as “technological hallmarks of early agriculture in North China.” However, they note, the functional foundations of this advanced toolmaking capability “remain insuf­ficiently tested.”

The research team also noted that most analyses of the transition from the Upper Paleolithic to the Early Neolithic (ca. 15,000–8,000 BP) in ancient China have viewed tools through “the lens of food production.”

“Within this framework, cutting tools, including early flakes and blades and later ground-edged sickles and knives, are often interpreted primarily as implements for harvesting cereals through cutting stems and leaves,” they explained.

The researchers said these earlier findings made them wonder whether this “food-focused perspective” could have led researchers to miss the broader range of plant resource exploitation possibilities in some of the 15,000-year-old stone tools previously discovered, prompting their replica-based experiments.

“The development of stone tool technology in North China provides a framework for reassessing this long-term relationship between plant use and technological change,” they explained.

Experiments Reveal Ground-Edged Tools Were Multifunctional Implements

To test their hypothesis, Chen and colleagues analyzed 140 stone artifacts previously collected from the Peiligang site in Henan Province, China. This included some 15,000-year-old Upper Paleolithic flaked stone tools and several more advanced Early Neolithic flaked and ground-edged stone tools.

Rather than test irreplaceable artifacts, the study authors created realistic experimental replicas.

Testing the effectiveness of the oldest, most rudimentary stone flake designs and the more technologically advanced ground-edged tools for harvesting seed-bearing grasses, the researchers found little measurable advantage between the two designs.

However, when the researchers compared the 15,000-year-old stone flake tools against ground-edged tools made thousands of years later, they found the more technologically advanced tools were “significantly more efficient at cutting thick-stemmed weeds and fiber-yielding plants.”

“Upper Paleolithic flaked tools were multifunctional implements used for processing diverse plant and animal materials, and Early Neolithic flakes continued to serve similarly flexible roles,” the study authors explain. “In contrast, Early Neolithic ground- edged tools show marked specialization in plant- related tasks.”

More Advanced Tools Emerged Through Broader Functional Demands

When discussing the experimental results, the team noted that their findings were supported by microfiber and starch residues found on some of the ancient tools, suggesting that “ground- edged sickles and knives were used not only for plant foods but also for harvesting and processing fibrous plants.”

“These findings indicate that ground- edged cutting tools emerged through broader functional demands, including fiber production, and potentially vegetation clearance, rather than cereal harvesting alone,” they explained.

Beyond the food-harvesting uses of ground-edged tools, Chen and colleagues said their identification of non-food plant labor like fiber production as an important driver of technological evolution and specialization “reframes the emergence of ground- edged tools as part of a broader technological and economic reorganization in early Holocene East Asia.”

“These findings identify nonfood plant work as an important contributor to the adoption of ground-edged cutting tools and show that tools conventionally linked to early agriculture were shaped by broader demands than food production alone,” they explained.

Finally, the study authors suggested that their analysis of 15,000-year-old Chinese stone tools could “invite renewed attention” to ancient fiber-based economies and nonfood plant use during forager–farmer transitions and in early farming societies beyond China.

The study “Plant fiber exploitation contributed to the emergence of ground-edged cutting tools in North China” was published in Proceedings of the National Academy of Sciences. 

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.

Harvard-Smithsonian Center for Astrophysics scientists studying water ice believed to be stored in the Moon’s ‘pits of eternal darkness’ have concluded that there likely isn’t enough of this critical resource to support long-term future human colonies, meaning visions of large-scale cities on Earth’s largest natural satellite may be more science fiction than science fact.

Conversely, the researchers calculated that smaller settlements with fewer than 10,000 human colonists could have enough accessible water to survive for centuries. They also suggested that other technological advances in water harvesting or advances in scanning techniques that explore below the top few meters of surface regolith may reveal significant amounts of hidden lunar water.

Water Ice Stored in Moon’s Pits of Eternal Darkness

The Moon’s surface is covered with visible evidence of asteroid collisions. Along with its textured appearance, some of these massive impact craters contain areas that are permanently shaded from direct sunlight.

The Harvard-Smithsonian research team behind the new study said some of the earliest “pits of eternal darkness” could be over one million years old. More critically, they can maintain a temperature of 110K, or just above absolute zero. At this low temperature, frozen water ice trapped in the sunless craters won’t lose more than a millimeter of thickness to space every billion years.

When announcing the new study, the researchers noted that “a succession of Moon-orbiting missions” has mapped out possible locations of stored water ice since 2013. The results suggested that the Moon’s pits of eternal darkness may contain as much as a billion tons, with the largest concentrated around the Moon’s northern and southern poles.

Since those missions, scientists and industrialists have begun to speculate about the viability of long-term human lunar habitation. Unlike astronauts trapped in capsules or space stations, lunar colonists could theoretically possess enough on-site water to support farming, full-service bathroom facilities, and production of hydrogen-based fuels.

Still, researchers wondered if one billion tons of stored water ice is enough to support the types of cities that billionaire industrialists and science fiction authors have proposed.

On-Site Solar Power Could Support One-Million-Person Lunar City

To start, the team modeled how long large human settlements ranging from 100,000 to one million people could survive on the water stored in lunar pits of eternal darkness. This included water-recycling rates up to 98%, as achieved on the International Space Station (ISS).

After running the numbers, the team found mixed results.

First, even colonies up to one million humans wouldn’t run out of power. The team said that number is based on solar power generation and excludes nuclear reactors.

Instead, the Harvard-Smithsonian team proposed constructing one-kilometer-tall solar energy towers near the rims of the craters. Their models suggest that an array of towers covered in photovoltaic arrays could generate three gigawatts of usable electricity.

The team noted that the materials needed to build solar panels, including the primary ingredient, silicon, are plentiful on the Moon, meaning future lunar colonists could manufacture new solar power-generating towers on-site. Such lunar colonists could theoretically maintain enormous AI data centers near these towers capable of servicing paying customers back on Earth.

“That would be the start of a true lunar economy,” the research team explained.

Even Generous Water Ice Estimates Limit Large Lunar Colonies

When the researchers crunched the water numbers, long-term lunar habitability became significantly more dubious. In fact, most estimates had future lunar colonists exhausting the most generous one-billion-ton projected supply of water ice within “a few years.”

When researchers modeled an ISS-level water recycling efficiency level using those same water estimates, a colony of one million humans would run out of water “in just over a century.”

“And today’s best estimates of the amount of water on the Moon are about 30 times less than a billion tons, shortening the time to water exhaustion by the same factor,” they add.

For example, if more conservative ‘pits of eternal darkness’ water ice estimates are closer to reality, the researchers said that “even a small city” likely wouldn’t make it past a decade before they had tapped the Moon dry.

Untapped Sources Could Improve Long-Term Habitation Prospects

Fortunately, the news was not all bad. When the team assumed a smaller “Moon village” of over one thousand people, up to a larger settlement of 10,000, the researchers found that the water ice stored in the Moon’s pits of eternal darkness “would instead be sustainable for several centuries or more.”

The team also suggested alternate solutions for supporting a larger, long-term lunar settlement. These included potential improvements in water recycling, improved farming efficiency, or mining nearby asteroids for water.

The team also noted that additional pockets of stored lunar water ice may be awaiting discovery, suggesting that finding such lunar water may be easier than achieving sufficient farming and recycling efficiency improvements.

“Current water surveying techniques do not reach below the surface more than a few meters, while the rubble-like rocks of the surface regolith typically extend tens of meters down and may contain water in the cold traps,” they explained.

The study “No Cities on the Moon: a Billion Tons of Water is not enough for Sustainability” was published in Frontiers in Space Technology. 

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.

Scientists investigating a 66-million-year-old mystery have revealed that a bird feather embedded in fossilized dinosaur excrement suggests that the ancestors of modern birds who survived the dinosaur-killing asteroid that also wiped out all other ancient bird species benefited from the waterproofing properties of their feathers.

The newly analyzed bird feather fossil that provided the missing clues comes from an extinct bird group called Hesperornithiforms and not from the ancestor of modern birds, Neornithes.

However, the team said subtle differences between the species suggest previous theories crediting adaptation to water diving as the key to Neornithes’ survival were likely on the right track.

Survival of Modern Bird Ancestors Posed a 66-Million-Year-Old Mystery

When a huge piece of space rock slammed into Earth, killing off virtually all dinosaur species save the ancestors of modern birds, the event also left behind a 66-million-year-old mystery. How did these ancient avians survive this apocalyptic event, resulting in every bird species we see today?

Jingmai O’Connor, the associate curator of fossil reptiles at the Field Museum in Chicago, said her career has been spent analyzing fossils to try to answer this single, critical question. However, unlike the new poop-encased bird feathers, most were not so ‘naturally’ protected from the ravages of time.

“It’s such a beautiful, well-preserved feather, from such an unexpected source, and it’s exciting that it could help us answer this huge question in paleontology,” explained the lead author of a study detailing the new analysis. “As far as I know, no one has ever thought to look for feathers or to study feathers in coprolites, so this project was really exciting.”

Dinosaur Dropping Provided Effective Preservation Medium

Researchers discovered the ancient bird feather in 2016 in Montana. Although she initially suspected it could be a coprolite rock (fossilized feces), O’Connor said she couldn’t confirm the theory for a decade.

The situation changed when O’Connor and Nate Carroll, a co-author of the paper and paleontologist at the Carter County Museum in Ekalaka, Montana, gained access to the micro-CT scanner at USC’s medical campus in Los Angeles, California. According to O’Connor, that’s when “the full feathery fabric of this fossil feces” started to finally reveal itself.

“Every hour processing the data revealed another feather, another scale, another bone—in stunning 3D,” Carrol also recalled.

Along with multiple feathers and tiny fish scales, the ancient dinosaur poop, which may have come from a Tyrannosaurus Rex, also contained legs from a hesperonithiform bird.

O’Connor said hesperonithiforms were ancient aquatic birds with similarities to modern loons. Critically, these cousins of the modern bird ancestor group had evolved specialized feet to hunt for fish by diving deep into the water.

“The feathers showed adaptations for being underwater that we see in living aquatic birds,” O’Connor explained.

Notably, the team said this evolution likely cost ancient hesperonithiforms like the one that was consumed by a dinosaur the ability to fly.

Connection to Modern Birds Offers a Solution 

Although the bird group represented by the fossilized feather did not survive the dinosaur-killing asteroid, its connection to the ancestor of modern birds appears to support a previously proposed theory that adaptation to water may have helped Neornithes survive. O’Connor said she thinks that small differences in the feathers of the two ancient bird species hold the answer to a 66-million-year-old mystery.

“We think the types of feathers that these birds had, and/or the way they molted those feathers, may have been one of the underlying causes of the selectivity of the end-Cretaceous mass extinction,” the researcher explained, adding that this is “essentially why some birds died out and why others survived.”

Specifically, O’Connor pointed to the “smaller, fuzzy, primitive body feathers” found on the extinct bird “that we associate with dinosaurs and enantiornithines” alongside more modern-looking waterproof adaptations.

The team said that these evolutionary relics suggest that hesperornithiforms like the one that left behind its feathers were an evolutionary bridge between older bird groups and the Neornithes that survived the cosmic collision. Even more critically, the team said these earlier feather structures may not have retained heat as effectively as Neornithes feathers, allowing one species to survive the asteroid and another to die in the extreme cold that followed.

“The hesperornithiforms retain primitive feather types that may not have been as efficient for insulation as modern plumaceous feathers, and that could explain why they went extinct along with the enantiornithines,” O’Connor explained.

The study “Bird feathers from a Late Cretaceous coprolite” was published in Current Biology. 

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.

Defense aviation company Hermeus has announced the development of Ramjet-X, its next-generation ramjet propulsion test vehicle capable of carrying test payloads to high Mach speeds.

The company said Ramjet-X, designed to launch mid-flight from a carrier aircraft, offers the key advantages of competitive high-Mach test platforms while keeping costs low enough for a wider range of mission profiles.

Pre-flight testing of Ramjet-X is already underway, with its first official prototype test flights expected in 2027.

Ramjet-X Will Launch Mid-Flight from Quarterhorse

Most conventional jet engines can’t achieve supersonic speeds without dumping raw fuel into an afterburner and literally rocketing past the sound barrier. To travel at high Mach speeds without relying on rocket-style propulsion, engineers have turned to ramjet engines.

While ramjets are effective, they rely on the high-speed influx of air to operate. This limitation means aircraft equipped with this type of propulsion must be propelled to higher speeds by another craft or booster rocket before they can engage.

In an email to The Debrief, a Hermeus spokesperson explained that current options often rely on “large and expensive” boosters that are discarded after each test. Conversely, Ramjet-X relies on the company’s reusable aircraft to reach launch velocity.

“Ramjet-X is designed to be carried by Quarterhorse, which provides the speed and altitude required for deployment,” the company told The Debrief.

The company could not disclose what speed Quarterhorse must achieve before it can launch Ramjet-X. However, the spokesperson did note that the launch craft is designed to return to home base for future missions.

When asked about Ramjet-X’s specific operating velocity once it disengages from Quarterhorse and engages its ramjet propulsion system, the company could only say the vehicle will operate at “High-Mach speeds.”

Conventional ramjets use a combination of high-velocity air and fuel to achieve extreme velocities. Hermeus said they cannot disclose specifics about Rocket-X’s fuel requirements.

Mission Profiles and Repeatable Architecture

Because of the sensitive nature of potential future missions, Hermeus was cautious about sharing specifics of any planned missions. The company also couldn’t provide technical details on what a typical mission profile might look like.

However, a Hermeus spokesperson told The Debrief, the vehicle’s architecture “allows customers and partners to integrate payloads, sensors, communications and computer systems, autonomy, material samples, propulsion technologies, and other experimental hardware and software onto Ramjet-X for testing in representative sustained high-Mach conditions.”

Hermeus also highlighted the potential cost savings of a “repeatable platform, launch architecture, and flight-test infrastructure,” designed to dramatically lower costs without sacrificing versatility or reliability.

“Instead of relying on a large dedicated expendable booster to accelerate the test vehicle into its ramjet operating regime, the launch aircraft provides much of that energy and then returns to fly again,” the company told The Debrief. “This architecture allows Hermeus to fly more by reducing the cost of expendable launch hardware.”

“High-speed flight testing is extremely expensive, and you don’t get many shots at it,” Hermeus CEO Zach Shore explained.

“Another Order of Magnitude Reduction”

Hermeus said specific unit costs are not currently available. However, they said a projected cost per minute of high-Mach test time “is in the low $100k’s per minute.” For comparison, the company highlighted the historic and current costs of high-Mach flight testing.

“Most of the below comparisons are rocket-based but will give you an idea how costly high-Mach tests are and why Ramjet-X will fundamentally change the equation,” Hermeus told The Debrief.

Older examples include NASA’s X-43, which achieved around 21 seconds of high-Mach flight, and the Air Force’s X-51, which achieved around 350 seconds. Hermeus said both multi-year efforts cost around $450 million each in today’s dollars.

Current options include rocket-powered test flights aboard Rocket Lab’s HASTE, which Hermeus said run $10-20 million each, “not including the expendable cruise or glide vehicles.” The company also pointed to Stratolaunch Talon-A missions.

“Even though fully reusable, (they) are $10-12m per flight for a few min of on-condition time,” the company told The Debrief.

Conversely, Hermeus said its current projections of less than a million per minute offer potential customers “another order of magnitude reduction in the problem that matters most.”

“Ramjet-X is being designed around simplified manufacturing, rapid production, and expendability in meaningful quantities rather than the traditional model of building a small number of highly bespoke high-speed test articles as was done in other high-speed airbreathing flight test programs like X-43 and X-51,” the company told The Debrief. 

Development of Ramjet-X is already well underway

When detailing the newly announced Ramjet-X’s benefits, Shore noted that their system gives them a way to place new systems into sustained high-Mach environments “without building an expensive one-off test program every time.”

“Bringing speed, sustained flight, and scalability all into one system lowers the barriers to gathering extremely valuable data from these conditions and accelerates programs for both us and our customers,” the Hermeus CEO explained.

When announcing Ramjet-X, Hermeus said the vehicle’s ramjet engine is already undergoing extensive testing at its Florida-based HEAT facility. Future tests will occur at the company’s California headquarters, with the first flight tests planned for 2027. 

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.

A University of Cambridge-led research team has announced the discovery of a 560-million-year-old animal fossil preserved in three dimensions (3D) in a sheep field in the Norwegian Arctic.

The exceptionally rare Ediacaran Period fossil is the first of its kind in Europe in decades and gives scientists a unique window into a period of Earth’s history when the first complex life forms began to appear.

The discovery suggests the site could hide an entire lost ancient ecosystem that has remained hidden for hundreds of millions of years.

3D Fossil of 560-Million-Year-Old Lifeform ‘Unlike Animal Life Today’

When announcing the historic discovery, the Cambridge-led team noted that the fossil, called a Charnia, resembles a fern more than any animal life we would likely recognize today.

For example, Charnia has none of the organs we typically associate with animals. The archaic life form also lacks a mouth or visible means of locomotion. The closest modern comparison would be a sedentary jellyfish.

While previous efforts have identified ancient animal-life fossils from this period, the team noted that most are found as “flat impressions.” As a result, Professor Neil Davies from Cambridge’s Department of Earth Sciences said that many fossils from this period “occur as impressions where they’ve been squashed down under layers of rock,” like a flower pressed into a book.

“As a fossil record, the Ediacaran has several things working against it, primarily that most organisms were soft-bodied and skeletons hadn’t evolved yet, so that they are harder to preserve,” the team member and co-author of the study detailing the research explained.

Dr Veema agreed, while noting the difficulty in finding such rare specimens.

“Fossils need to be embedded within sedimentary rocks to be found, so if the rocks themselves are less common, then that makes the fossils harder to find,” the researcher explained. “Most Ediacaran fossils come from just a handful of locations, which makes it exciting to find them somewhere new.”

Fortunately, the newly identified 560-million-year-old life form was preserved in all three dimensions. The team said that discovering an ancient life form preserved in 3D is incredibly rare, particularly for soft-bodied organisms like Charnia. Finding one from this extremely ancient time, when animal life first began to appear, is even more unlikely, making the discovery unusually rare.

Well-Preserved Charnia Reveals Previously Unknown Details

560 million years ago, when this Charnia was still alive, evidence suggests that it was buried during an ancient underwater avalanche. This sudden submergence also filled the animal’s body with sediment. The researchers said these events caused the fossil to become preserved in 3D

For example, the research team identified small ridges along the animal’s branches. Called keels, these extremely subtle features had never been detected in other, flatter Charnia fossils.

Dr Yorick Veenma, from Cambridge’s Department of Earth Sciences and the lead author of the study detailing the team’s discovery, said finding a 3D fossil from this archaic time has provided them with an entirely new perspective.

“When you see the same species preserved in a different way, you start noticing properties you hadn’t seen before,” Dr. Veenma explained.

“There May Be a Whole Undiscovered Community of These Very Early Organisms”

Although scientists have found a few fossils from this period, they are often from the same handful of sites. However, this is the first time one has been found in Norway. Dr. Veema said this shows that discoveries can be made “in less familiar places.”

The researchers also successfully identified other components of the ancient ecosystem that this Charnia fossil called home. Future efforts may reveal that it was one small part of a larger, ‘lost’ ancient ecosystem supporting a variety of complex life forms.

“There may be a whole undiscovered community of these very early organisms preserved up there,” Davies explained. “Weird little umbrella-shaped blobs, things that don’t fit with what people know from elsewhere.”

“There are a whole host of different things that were not known before,” the researcher added.

The study “Charnia and other late Ediacaran macrofossils preserved in turbiditic deposits of the Indreelva Member (Finnmark, Norway)” was published in Paleontology.

Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.