An estimated 1.4 billion adults worldwide between the ages of 30 and 79 have high blood pressure (hypertension), a major contributor to illness and death. Although medications that lower blood pressure are proven to reduce the risk of cardiovascular complications, approximately half of patients do not take their prescriptions as directed.

“We have evidence that poor adherence to antihypertensive medication is associated with worse outcomes,” explained presenter, Miss Qianqian Yang from the University of Oxford, UK. “However, previous data has come from observational studies and could be confounded by other factors. We undertook an analysis of randomized trial data to assess the true impact of adherence on the benefits of antihypertensive treatment.”

Major Study Examines the Impact of Missed Blood Pressure Medication

To better understand how consistently taking medication affects its benefits, researchers analyzed individual patient data from 91,339 participants across nine clinical trials. Each trial compared a blood pressure treatment (intervention group) with an alternative approach (comparator group: either placebo or a less-intensive regimen).

The researchers divided participants into two categories based on how closely they followed their prescribed treatment. Those who took at least 80% of their assigned medication were considered to have higher adherence, while those who took less than 80% were placed in the lower adherence group.

Even with the regular monitoring and structured conditions of clinical trials, patients became less consistent about taking their medication as time passed.

“A decline in adherence over time was apparent, even in the structured setting of trials,” noted Miss Yang. Overall, 88% of participants met the higher adherence threshold during the first year, but that figure had dropped to just 79% by the fifth year.

Skipping Blood Pressure Pills Reduces Treatment Benefits

The difference in medication adherence was reflected in how much patients’ blood pressure improved.

Among participants with higher adherence, systolic blood pressure, the top number in a blood pressure reading, was 5.2 mmHg lower in the intervention group than in the comparator group. For those with lower adherence, the difference was considerably smaller at just 3.0 mmHg.

Researchers then examined whether these differences translated into protection against major cardiovascular problems. The outcomes included strokes, heart attacks (myocardial infarction), ischemic heart disease, and heart failure that resulted in hospitalization or death.

The findings revealed a striking contrast. Among patients who consistently followed their treatment plans, the intervention group experienced an 11% lower incidence of major cardiovascular events compared with the comparator group. However, among patients with lower adherence, there was no statistically significant reduction in these events.

“Notably, our results reinforce the saying that ‘drugs don’t work in patients who don’t take them.’ Patients with lower adherence derived little or no cardiovascular benefit, whereas those with higher adherence had greater reductions in blood pressure and prevention of cardiovascular events,” said Miss Yang.

Helping Patients Get Lifesaving Heart Protection

The researchers believe that helping people take their medication consistently should become a greater priority in the treatment of high blood pressure. They recommend more routine assessments of medication adherence, along with better patient education and practical strategies to make treatment easier to follow.

Possible approaches include simplifying medication schedules, combining multiple treatments into a single pill, and prescribing longer-acting drugs that can help limit the consequences of an occasional missed dose.

Professor Felix Mahfoud, Chair of the ESC Communication Committee, emphasized that missed medication has received too little attention as a contributor to poorly controlled blood pressure.

“For years, we have neglected non-adherence to medication as a cause for uncontrolled hypertension. Assessment of adherence should become a routine part of hypertension care so patients do not miss out on life-saving benefits. As healthcare providers, we are here to have open, non-judgmental conversations with our patients about any barriers they may have to taking medication, to help improve adherence.”

The research, known as the Alcohol Intake and Health Study, was originally commissioned by the U.S. federal government to help shape updated national dietary recommendations. Researchers estimated that people who consume an average of 14 alcoholic drinks per week face a 1 in 25 lifetime risk of dying from alcohol-related causes. By comparison, consuming up to seven drinks weekly was linked to only small increases in risk for most health conditions.

“Even low levels of alcohol use come with health risks,” says lead study author Kevin Shield, Ph.D., an associate professor at the University of Toronto and a senior scientist who leads the World Health Organization (WHO)/Pan American Health Organization (PAHO) Collaborating Centre in Addiction and Mental Health. “And that risk continues to increase the more someone drinks.”

How Scientists Measured the Health Risks of Alcohol

To better understand the long-term consequences of drinking, Shield and his colleagues in the United States and Canada investigated how alcohol consumption over a lifetime contributes to disease and premature death among Americans.

Medical experts first examined more than 7,200 scientific publications covering illnesses and injuries associated with alcohol. Using this evidence, they estimated the risks for individual health conditions and combined those findings with large national health data sets. Statistical models then allowed the team to calculate how different levels of alcohol consumption affect the likelihood of developing serious health problems or dying prematurely.

The findings provide specific estimates that are missing from the latest U.S. Dietary Guidelines. The updated recommendations simply encourage Americans to “limit alcoholic beverages” without identifying a particular consumption threshold. Earlier versions advised men to drink no more than two alcoholic beverages per day and women no more than one.

“While the new U.S. Dietary Guidelines contain a useful ‘less-is-best’ message, they provide no quantitative framework. Our study was designed to do just that across the drinking spectrum,” says study co-author Timothy Naimi, M.D., M.P.H., director of the University of Victoria’s Canadian Institute for Substance Use Research and an adjunct professor at Boston University.

“It turns out that two drinks per day, which might be considered ‘moderate’ from a social standpoint, is associated with a substantially elevated risk of a premature death caused by alcohol,” explains Naimi.

Moderate Drinking Offers No Significant Overall Health Benefits

The researchers looked beyond the risk of premature death to examine alcohol’s connection to a wide range of immediate and long-term health problems. These included cancers (e.g., esophageal, oral, and breast), cardiovascular disease, liver disease, and injuries.

One of the study’s most important findings challenges the longstanding belief that consuming small amounts of alcohol can improve health, particularly heart health.

“We did not observe a significant protective effect of alcohol on health at any level of consumption,” says Shield. “At low levels, alcohol may be associated with a reduced risk of ischemic heart disease and stroke. But when you look across the full range of health outcomes, including cancer and other chronic diseases, those potential benefits are outweighed by the risks even at 7 drinks per week.”

In other words, while some studies have suggested that light drinking may benefit certain aspects of cardiovascular health, those possible advantages do not translate into an overall health benefit once alcohol’s links to cancer and other diseases are taken into account.

Why Individual Alcohol Risks Can Differ

Although the analysis drew on extensive scientific evidence, the researchers emphasize that its estimates describe risks across populations rather than predicting precisely what will happen to any particular person.

Shield says the statistical calculations relied on “the best possible data.” However, he cautions that individual circumstances can substantially influence the results.

“However, we can’t assume that means one person’s individual health risk is the same as what is reported here — that depends on other factors like lifestyle, genetics, drinking patterns, and other choices that differ person to person.”

To estimate alcohol’s overall impact, the researchers calculated risks for health conditions already known to be caused by alcohol and combined them into a broader assessment. However, scientists are continuing to investigate additional possible consequences of drinking, including emerging evidence connecting alcohol consumption to pancreatic cancer.

“Understanding those relationships, and how much alcohol contributes to those risks, is an area that still needs further work,” says Shield.

What the Findings Mean for U.S. Drinking Guidelines

The results suggest that alcohol-related health risks become more pronounced when consumption exceeds one drink per day, regardless of whether the person is male or female. This provides a more specific reference point for people trying to understand how their drinking habits might affect their long-term health.

Rather than suggesting that any particular amount is completely safe, the findings show how risks increase with greater consumption and why drinking less generally reduces exposure to alcohol-related harm.

“Having a clearer threshold helps people better understand what level of drinking is associated with increased risk and make more informed decisions when drinking,” says Shield.

The study has also raised questions about how scientific evidence was incorporated into federal dietary recommendations.

In an accompanying editorial, Robert M. Vincent, a former Associate Administrator for the U.S. Substance Abuse and Mental Health Services Administration, offers his perspective on the circumstances surrounding the research and its role in the development of national guidance.

“The Alcohol Intake and Health report was explicitly invited to inform alcohol guidance during development of the Dietary Guidelines for Americans, 2025-2030,” he writes. “Despite the study’s adherence to its mandate, its findings were sidelined.”

The findings, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, were based on genetic data from more than 13,500 participants in the landmark ASPREE Trial (Aspirin in Reducing Events in the Elderly). Scientists examined whether differences in participants’ genes could help explain why aspirin might affect dementia risk differently from one person to another.

Aspirin Linked to 70% Lower Dementia Risk in Certain People

The most striking results involved genes associated with platelet count. Platelets are small components of the blood that help form clots, and researchers wanted to determine whether genetic variations related to platelet levels could influence aspirin’s potential effects on dementia.

After assigning participants genetic scores associated with platelet count, the team compared dementia rates among those who received aspirin and those given a placebo.

Among people in the highest 20 percent of platelet count genetic scores, just 1 percent of aspirin users developed dementia, compared with 3.3 percent of participants taking a placebo. That difference translates to approximately a 70 percent lower relative risk of dementia among those receiving aspirin.

However, the apparent benefit was accompanied by a significant safety concern. In the same genetic group, 4.4 percent of aspirin users experienced major bleeding, compared with 2.1 percent of those receiving a placebo.

A Genetic Clue Could Change Dementia Prevention

Lead author Dr. Peter Fransquet, a Research Fellow at Monash’s School of Public Health and Preventive Medicine, said the results suggest that a person’s genetic makeup could eventually play an important role in determining which dementia prevention strategies are most appropriate.

“Previous trials found aspirin didn’t prevent dementia when everyone was considered together,” Dr. Fransquet said.

“Our findings suggest there may be more to the story.

“In people with this particular genetic profile, we saw substantially fewer cases of dementia among those taking aspirin.

“It raises the possibility that genetics could one day help us identify who may benefit from a preventive treatment, rather than taking a one-size-fits-all approach.”

The possibility of more targeted prevention is especially important as dementia becomes increasingly common. Dementia Australia estimates that approximately 446,500 people in Australia are living with the condition in 2026. That number is expected to exceed one million by 2065.

Blood Platelets Reveal an Unexpected Dementia Connection

Previous research has connected dementia with platelet activation and aggregation, the processes through which platelets become active and stick together. However, scientists have had a less complete understanding of how a person’s overall platelet count might relate to dementia.

The new findings point toward platelet biology as a potentially important area of investigation. Notably, the genetic association identified by researchers did not involve the well-established genetic risk factors typically linked to Alzheimer’s disease and other forms of dementia.

“What’s particularly interesting is that the signal wasn’t linked to the established genetic risk factors for Alzheimer’s disease and dementia,” Dr. Fransquet said.

“Instead, it’s pointing us towards platelet biology and gives us a new avenue to investigate.”

Why More Research Is Needed Before Taking Aspirin

Although the findings suggest that aspirin could have different effects depending on a person’s genes, researchers emphasize that the results must be confirmed before they can guide medical recommendations.

The next step is to investigate whether the association appears in other populations. Scientists would then need to conduct a clinical trial specifically involving people with the genetic profile identified in the analysis.

“We now need to confirm the finding in other studies and ultimately test it in a trial designed specifically for people with this genetic profile.

“People shouldn’t start taking aspirin to prevent dementia on the basis of this study without consulting with their doctor, particularly given the increased risk of serious bleeding.

“If it holds up, the fact that aspirin is already cheap and widely available could make personalized dementia prevention a real possibility.”

Although the treatment did not significantly lower blood pressure compared with a placebo device across all participants, researchers observed encouraging results in patients with more severe hypertension. The findings suggest that stimulating nerves in the ear could eventually help certain people whose blood pressure remains elevated despite taking medication.

The results come from the SCRATCH-HTN trial, published in Hypertension, a journal of the American Heart Association. Researchers emphasize that larger studies are needed to determine whether the approach can provide meaningful benefits and which patients might respond best.

How Ear Nerve Stimulation Could Lower Blood Pressure

The experimental treatment uses a technique called transcutaneous autonomic neuromodulation (tAN), which aims to influence the autonomic nervous system. This network of nerves automatically controls essential bodily functions, including heart rate, digestion, and blood pressure.

By delivering mild electrical signals to nerves in the ear, researchers hope to influence the body’s natural mechanisms for regulating blood pressure without requiring an invasive procedure.

The handheld device, developed by Afferent Medical Solutions, uses two small clips positioned on the tragus, the small flap of cartilage located just in front of the ear canal. These clips deliver gentle electrical stimulation, allowing patients to administer the treatment themselves without visiting a clinic.

Clinical Trial Tests the Device in 63 Patients

The clinical trial, funded by the National Institute for Health and Care Research (NIHR), enrolled 63 people with uncontrolled hypertension. All participants were already taking at least one medication to lower their blood pressure, but their readings remained above recommended levels.

Researchers randomly divided the participants into two groups. One received active nerve stimulation, while the other used a sham device designed to serve as a comparison. This approach helped investigators assess whether the electrical stimulation produced benefits beyond those associated with using the device itself.

Participants used their assigned devices for 30 minutes daily during the first two weeks. For the following 10 weeks, they reduced their sessions to once per week.

The results showed that the treatment was safe and generally comfortable for participants. Most also followed the prescribed schedule, suggesting that the technology could be practical for regular use at home.

However, when researchers compared blood pressure changes across the entire study population, they found no statistically significant difference between patients receiving active stimulation and those using the sham device.

Promising Results in Patients With Severe Hypertension

Despite the lack of a significant overall benefit, the researchers identified a potentially important finding among participants who entered the trial with more severe hypertension.

A prespecified subgroup analysis, meaning the researchers had planned this comparison before examining the results, revealed a greater reduction in blood pressure among these patients when they received active nerve stimulation rather than the sham treatment.

This finding raises the possibility that the technique may work better for people with particularly difficult-to-control blood pressure. However, the trial was relatively small, and the subgroup results require confirmation in larger studies before any conclusions can be drawn about its effectiveness.

Dr. Ajay Gupta, Chief Investigator, Clinical Reader at Queen Mary University of London and Consultant Physician at Barts Health NHS Trust, said:

“This is an exciting, highly patient-acceptable technology that could ultimately provide a cheap, scalable solution for millions. Although the trial did not achieve significance across the broad unselected group, those with more severe hypertension exhibited a clear blood pressure reduction in the active group compared to sham.

“As the first and most thorough study of its kind, this points towards important new research directions that could help us understand whether non-invasive neuromodulation can benefit particular groups of patients with uncontrolled hypertension.”

A Potential New Option for Hard-to-Control Blood Pressure

High blood pressure, also known as hypertension, is a major contributor to cardiovascular disease and increases the risk of heart attacks and strokes. It places additional strain on blood vessels and the heart, potentially causing serious damage over time.

Although medications help many patients manage their condition, a substantial number continue to have blood pressure readings above recommended targets even while receiving treatment.

This ongoing challenge has encouraged scientists to explore additional approaches that could complement existing therapies.

Ear nerve stimulation is one such possibility. Because the device is small, does not require surgery, and can be used at home, it could offer a convenient option if future research establishes that it reliably lowers blood pressure in certain patients.

For now, the findings represent an early step rather than proof of an effective new treatment. The researchers say larger clinical trials will be essential to confirm the encouraging results in patients with severe hypertension and identify which groups, if any, could benefit most from this approach.

The study, published in Science Advances, introduces a new approach called “ousiometrics,” which uses mathematical methods to measure the essential meaning of language. Its most striking finding is that the words people use show a consistent and widespread preference for safety over danger.

This hidden safety bias could transform how researchers study language, understand human behavior, and develop artificial intelligence systems that interpret what people say and write.

Scientists Discover a Hidden Safety Bias in Human Language

Since the 1950s, much of the scientific understanding of word meaning has relied on a framework developed through pioneering research by psychologist Charles Osgood and others. Known as the VAD model, it describes meaning through three emotional dimensions: valence (positive vs. negative), arousal (excited vs. calm), and dominance (controlling vs. submissive).

This approach became influential in psychology, linguistics, and artificial intelligence, particularly in systems designed to identify the emotional tone of written language.

However, the University of Vermont researchers found evidence that this long-established model overlooks important aspects of how meaning is organized.

Their analysis examined billions of individual uses of more than 20,000 words across a wide range of real-world texts. Using advanced computational techniques, the team identified a different underlying structure. They found that the three dimensions in the traditional VAD model are not independent of one another, as previously assumed.

Instead, their results indicate that word meaning can be more effectively described through three separate dimensions: power (weak vs. powerful), danger (safe vs. dangerous), and structure (ordered vs. chaotic).

The research, supported by the US National Science Foundation, Google, MassMutual, and other funders, found that this new framework accounted for more than 90% of the variation in measured word meaning. The traditional VAD approach explained approximately 72%.

That improvement could be especially important as large language models, automated content moderation, and other AI technologies increasingly depend on understanding human communication.

Why Human Language Favors Safety Over Danger

One of the study’s most unexpected discoveries emerged when the researchers examined how words actually appear in everyday communication.

Across books, news reporting, social media, and spoken language, words associated with safety appeared much more frequently than those associated with danger.

This finding offers a new explanation for a familiar phenomenon called the Pollyanna principle, which describes the tendency for human language to lean toward positive rather than negative words.

For decades, researchers generally interpreted this pattern as evidence that people favor positive emotional expressions. The new analysis suggests that something more fundamental may be responsible.

According to the researchers, the apparent preference for positivity largely reflects an underlying preference for safety.

“The Pollyanna principle’s positivity bias,” the study concludes. “is, in fact, a one-dimensional projection of an underlying safety bias.”

“This is a big observation that comes out of this work,” said Peter Dodds, director of the UVM’s Complex Systems Institute and senior author of the study. “Expressions of safety are crucial to all language.”

Could Human Language Be Shaped by Survival?

The discovery raises an intriguing possibility: the structure of human language may reflect evolutionary pressures associated with staying alive.

From this perspective, words do more than communicate feelings. They also help people recognize threats, evaluate uncertainty, establish trust, and coordinate actions with others.

Being able to distinguish between safety and danger is essential to survival. The researchers suggest that this basic human priority may also influence how meaning is organized in language.

Throughout daily life, people constantly exchange information about whether individuals, places, situations, and behaviors are threatening or safe. The new findings suggest that these distinctions may be more central to communication than previously recognized.

They also offer a different interpretation of why positive language is so common. Rather than simply expressing happiness or approval, many positive words may convey a sense of security, stability, or predictability.

Julia Zimmerman, a postdoctoral researcher in UVM’s Computational Story Lab and a co-author of the study, said the three newly identified dimensions reflect experiences that are fundamental to human life.

“Power, danger, and structure,” she said, “are relevant to every person that’s ever lived.”

Researchers have also long recognized that people tend to favor language associated with goodness and low aggression. The team argues that these familiar tendencies may arise from the same deeper pattern.

“We now understand,” the team writes, that these are “shadows of an underlying linguistic safety bias.”

Although the results are consistent with a possible connection between language and survival, they do not establish that evolutionary pressures directly caused the safety bias.

A Discovery That Could Change How AI Understands Language

The findings have implications that extend well beyond linguistics.

Many artificial intelligence systems use sentiment analysis to determine whether language expresses positive, negative, or neutral feelings. Some approaches also draw on the traditional VAD framework to measure emotional meaning.

If that framework does not fully capture the underlying structure of language, systems built around it could overlook important distinctions in what people communicate.

The researchers suggest that incorporating power, danger, and structure could eventually help AI models interpret language more accurately and explain their assessments more clearly. This may be particularly useful when analyzing trust, risk, and decision-making.

In linguistics, the findings offer a different way to understand the foundations of meaning. Instead of treating emotional tone as the primary organizing principle, the new framework emphasizes distinctions related to strength, safety, and predictability.

Psychology could also be affected. Decades of studies have used the VAD model to investigate emotions, perception, and behavior. A different set of fundamental dimensions could encourage researchers to reconsider how some of those findings are interpreted.

The discovery may also interest neuroscientists. The human brain is highly sensitive to threats and signals of safety, and the newly identified linguistic bias suggests that these biological priorities may be reflected in language. This potential connection could help researchers explore relationships between brain activity and symbolic communication, although further research would be needed to establish them.

A New Tool Measures the Hidden Meaning of Words

To investigate these patterns, the researchers created analytical methods designed to measure meaning across enormous collections of written and spoken language.

One of their central innovations is the “ousiometer,” a tool that rapidly evaluates the essential meaning of large bodies of text and produces an average meaning score.

(The word “ouisa” comes from Ancient Greek and is a root for the English word “essence.”)

The ousiometer builds on an earlier tool developed by the research team called the “hedonometer” (a happiness meter). While that instrument measures the overall emotional tone of language, the new approach examines broader patterns of meaning.

The researchers demonstrated that the ousiometer can analyze material from remarkably different sources, including Jane Austen’s novels, Arthur Conan Doyle’s Sherlock Holmes stories, the New York Times, Wikipedia, Twitter, and transcripts of talk radio programs.

The tool can also track how meaning shifts as a story unfolds.

For example, the researchers analyzed an English translation of Victor Hugo’s Les Misérables and mapped its changing meaning throughout the novel.

They called this changing pattern an “ousiometric trajectory.” The visualization resembles the twisting shape of a multicolored protein, with the narrative moving across a grid based on four contrasting pairs: dangerous/safe, weak/powerful, gentle/aggressive, and bad/good.

By following this path, researchers can observe how the underlying meaning of the text changes from one section of the story to another.

Why Counting Word Frequency Changes the Results

Another important innovation involved distinguishing between words themselves and how often people actually use them.

In linguistics, researchers describe individual words as categories called “types,” while each appearance of a word in text is known as a “token.”

(For example, as a category “apple” is a type and every time the word “apple” is used in a sentence is a token.)

This distinction matters because a word that appears millions of times contributes much more to everyday communication than one that is rarely used.

Earlier research often gave each word equal importance, regardless of its frequency. The Vermont team instead incorporated how often words appear in real communication, allowing patterns to emerge that might otherwise remain hidden.

This approach was particularly important for identifying the widespread preference for safety-related language.

The ten-member research team was led by Peter Dodds and Chris Danforth, professors in UVM’s College of Engineering and Mathematical Sciences. Their collaborators included researchers from the Santa Fe Institute, the Complexity Science Hub in Austria, Howard Hughes Medical Center, the University of California, Berkeley, the University of Adelaide, and MassMutual Data Science.

Rethinking What Human Language Reveals About Us

Understanding this hidden safety bias could have consequences for how researchers study communication across society.

If words consistently reflect a preference for safety, that tendency may influence how stories are told, how information spreads, and how people interpret events and experiences.

The findings could eventually inform research into political communication, mental health messaging, and AI systems designed to interact with people.

More broadly, the study challenges the idea that human language can be understood primarily through emotions such as happiness, fear, and excitement.

Instead, the researchers propose that meaning has a deeper structure connected to power, danger, and order. Their findings suggest that language may reflect the challenges humans face when navigating uncertain environments, maintaining relationships, and identifying threats.

By revealing this previously overlooked structure, the team offers a new way to understand what words communicate and why certain kinds of meaning dominate everyday conversation. Human language, their research suggests, may be more closely connected to our fundamental need for safety than scientists have traditionally recognized.

Bennu completes one orbit around the Sun every 1.2 years and makes a relatively close approach to Earth about every six years, coming within roughly 300,000 kilometers (186,000 miles). NASA’s OSIRIS-REx mission traveled to the asteroid, collected material from its surface, and successfully delivered the samples to Earth in 2023.

On September 23, 2023, a capsule carrying approximately 120 grams of asteroid material landed in the Utah desert. Scientists around the world subsequently received small portions of the precious cargo for detailed study.

Among them was Maria Schönbächler, Professor of Isotope Geochemistry at ETH Zurich, whose laboratory received half a gram of Bennu material. Her team immediately began examining the samples for clues about the asteroid’s history.

The research, now published in Science Advances, has uncovered a distinctive chemical signature that not only helps identify Bennu’s origins but also provides new evidence about the processes that shaped the early Solar System.

Bennu’s Chemical Fingerprint Reveals Its Cosmic Relatives

To investigate Bennu’s origins, the ETH Zurich researchers examined isotopes of three elements: iron, titanium, and chromium.

Isotopes are different forms of the same chemical element that contain varying numbers of neutrons, giving them slightly different masses. By measuring the relative amounts of these isotopes, scientists can identify a material’s chemical fingerprint. These patterns provide clues about where an asteroid’s ingredients originated and, in some cases, when they formed.

The analysis revealed that iron and titanium are distributed remarkably evenly throughout Bennu’s material. It also uncovered a close chemical relationship between Bennu, the asteroid Ryugu, and a rare group of primitive meteorites known as CI meteorites.

CI meteorites are carbon-rich remnants of the early Solar System that have undergone relatively little alteration over billions of years. They are exceptionally uncommon among meteorites recovered on Earth.

Bennu, Ryugu, and CI meteorites share strikingly similar isotopic fingerprints, suggesting that their original materials came from the same reservoir of ancient cosmic dust. Their chemical signatures also differ substantially from those of other known asteroids, meteorite groups, and planets.

These similarities offer an important clue about where these objects formed and what conditions existed during the Solar System’s earliest stages.

Scientists Discover Bennu’s Unexpected Birthplace

For years, researchers generally believed that primitive asteroids like Bennu originated in the outer Solar System, perhaps in the same distant regions where comets formed. They also suspected that Bennu’s original material came together relatively late in the Solar System’s development.

The new findings challenge both assumptions.

Instead, the researchers propose that the material that became Bennu, Ryugu, and CI meteorites accumulated near a boundary known as the water-ice line.

This boundary marks the region in the disk surrounding the young Sun where temperatures were low enough for water vapor to freeze into ice. Around 4.5 billion years ago, it may have been a particularly important meeting place for material traveling from different parts of the developing Solar System.

Dust originating in both the inner and outer regions mixed near this boundary. Water ice helped the smallest particles stick together, allowing them to gradually accumulate into larger bodies.

“Bennu is a hybrid: the material does not clearly match either the inner or the outer Solar System,” says Schönbächler.

Its unusual chemical composition suggests that Bennu formed from a combination of materials originating in both regions rather than from a single, isolated source.

Jupiter May Have Played a Crucial Role in Bennu’s Formation

The researchers also developed a scenario explaining how this mixing could have occurred, with Jupiter emerging as a key player.

Jupiter began forming extraordinarily early in Solar System history, within approximately one million years of the Sun’s birth. At that time, the young Sun was surrounded by a rotating disk of gas, dust, and ice.

Within this disk, countless small particles gradually collided and stuck together, building larger objects through a process called accretion. Over time, some of these growing bodies became asteroids and planets.

As Jupiter rapidly increased in mass, its immense gravitational influence began reshaping the distribution of material throughout the disk.

The researchers suggest that the growing gas giant acted somewhat like a structural barrier, preventing most larger particles from crossing its orbital region while still allowing finer dust to move around it.

This fine material, originating from different parts of the disk, could then mix extensively near the water-ice line.

According to the proposed scenario, the parent bodies of Bennu and Ryugu, along with the objects that produced CI meteorites, formed from this thoroughly mixed material.

Jupiter may therefore have helped determine not only where these ancient asteroids formed but also which ingredients became incorporated into them.

Ancient Dust and Ice Reveal the Ingredients That Built Earth

The proposed formation scenario could also explain two of Bennu’s most intriguing characteristics: its abundance of water-bearing material and its chemical resemblance to the Sun.

Near the water-ice boundary, ice could evaporate as temperatures changed, releasing water vapor that later condensed again in cooler regions. This process would have helped concentrate water in the material from which Bennu formed.

Meanwhile, Jupiter’s influence may have limited the movement of larger particles, leaving the asteroid’s parent material dominated by fine dust.

Because these tiny particles could circulate and mix efficiently throughout the disk, they preserved a chemical composition that closely resembles the overall elemental mixture found in the Sun.

The process is somewhat similar to the way fine household dust spreads and settles across many different surfaces rather than remaining in one location.

This extensive mixing could explain why Bennu’s material retains such a representative sample of the ingredients present during the Solar System’s earliest history.

“Bennu may offer our best glimpse of the original mix of chemical elements from which the terrestrial planets were ultimately built,” as Schönbächler states.

Bennu is considered an exceptionally primitive asteroid because its material formed approximately 4.5 billion years ago and has experienced relatively little chemical alteration since then.

That makes its samples particularly valuable for reconstructing the conditions that existed before Earth and the other rocky planets finished forming.

By studying the asteroid’s chemistry, scientists can better understand how the Solar System developed and which processes determined the composition of its planets.

Bennu’s water-bearing minerals and organic compounds also make it important for investigating how early Earth obtained some of the chemical ingredients necessary for life.

Although these findings do not establish exactly how those materials reached our planet, they provide valuable evidence about where such ingredients originated and how they were distributed throughout the young Solar System.

A New Mission to Mars’ Moon Could Reveal More

Despite the new discoveries, several questions remain unanswered.

“We are now wondering whether other asteroids have the same isotopic signature as Bennu and Ryugu,” Schönbächler goes on to state.

Researchers also want to determine more precisely how Jupiter influenced the movement of dust and whether its gravitational effects were responsible for favoring the accumulation of particularly fine particles.

Additional asteroid samples could help scientists test the proposed formation scenario and establish whether Bennu’s chemical signature is shared by other ancient bodies.

With the Bennu analysis now complete, Schönbächler is looking ahead to another opportunity to examine material from the early Solar System.

Japan’s space agency, JAXA, is preparing a sample-return mission to Phobos, one of Mars’ two moons. The mission is scheduled to launch at the end of October 2026, with the goal of collecting material from the Martian moon and bringing it back to Earth.

“It would be exciting to also obtain this material to analyse it in my laboratory,” she says.

Schönbächler plans to apply to JAXA for access to the samples. However, the scientific community will need to be patient. The capsule carrying material from Phobos is not expected to return to Earth until 2031.

Those future samples could provide another important piece of the puzzle, helping researchers determine how different regions of the early Solar System exchanged material and ultimately produced the planets, moons, and asteroids we observe today.