Alpha Centauri Sending Stream of Objects Into Our Solar System, Scientists Propose
Nevertheless, that hasn't stopped intrepid astronomers from trying. In a case study published in the Planetary Science Journal and spotlighted by Universe Today, the researchers from The University of Western Ontario hypothesize a scenario in which our nearest stellar neighbor, Alpha Centauri, may be sending a steady stream of "interstellar material" our way.
And tantalizingly, what they found suggests that our solar system may already be flooded with visitors from the star system, which is about 4.25 light years away. These objects range from microscopic in size to well over 100 yards in diameter — a far more significant presence than the background level of gas and dust diffused throughout the cosmos.
However, the odds of encountering one of these objects within the heart our solar system remain exceedingly low, with only a one-in-a-million chance that an interstellar visitor is located within ten astronomical units, or just short of one billion miles, of the Sun, according to the scientists.
Though it appears as a single bright speck in the sky, Alpha Centauri is actually a triple star system, with several suspected exoplanets, including a super-Earth called Proxima Centauri b, with more thought to be lurking in the shadows. Two of the stars are Sun-like ones locked in a binary dance, while another star, a dim red dwarf, acts as the proverbial third wheel.
And with all those big personalities involved and clashing gravitational egos, it's likely that Alpha Centauri boots out a significant amount of material, some of which may have reached the Oort Cloud, a shell of icy objects that surrounds the solar system, the researchers said.
Alpha Centauri is also moving towards us, and in some 28,000 years from now, it'll reach its closest point at a distance of a little over three light years away, raising the odds of an interstellar influx in the future, too.
"Though mature star systems likely eject less material than those in their planet-forming years, the presence of multiple stars and planets increases the likelihood of gravitational scattering of members from any remnant planetesimal reservoirs, much as asteroids or comets are currently being ejected from our solar system," the researchers wrote in the study.
In fact, the astronomers estimated there could be over 1,000,000 objects larger than 328 feet in diameter from the nearby system lurking in the Oort Cloud. For reference, 'Oumuamua is believed to be anywhere between 328 to 3,280 feet long. That's a lot of refugees.
It's unlikely we'll ever detect the vast majority of them, though. And when you consider the astronomers determined that particles as small as just ten microns, or about the size of a human blood cell, could survive the ten million-year journey over, it sounds like our corner of the universe may be awash with interstellar particles that even our most advanced instruments will have no chance of picking up on.
A silver lining: the authors predict that around ten Alpha Centauri rejects could enter the Earth's atmosphere, where they'd be detectable as meteorites. With any luck, some of them could originate from one of the star system's exoplanets, providing a potential glimpse of worlds light years away.
"A thorough understanding of the mechanisms by which material could be transferred from Alpha Centauri to the solar system not only deepens our knowledge of interstellar transport but also opens new pathways for exploring the interconnectedness of stellar systems and the potential for material exchange across the Galaxy," the paper reads.
More on space: Don't Panic, But the Chances of That City Killer Asteroid Hitting Earth Just Almost Doubled
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Newsweek
4 hours ago
- Newsweek
Alzheimer's: Scientists Discover What Sparks Disease
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Lithium deficiency in the brain could be a cause of Alzheimer's disease—and a new potential target for treatment. Ten years in the making, this is the finding of researchers at Harvard Medical School who have revealed how lithium plays an essential role in brain function and may provide resistance against brain aging and Alzheimer's. Lithium is a chemical element, currently used as medicine to treat mood disorders like mania and bipolar disorder. "Most people associate lithium with psychiatric treatment. Our study shows, for the first time, that naturally occurring lithium plays a crucial role in maintaining brain health during aging—even at concentrations far below those used in clinical psychiatry," study authors Bruce Yankner and Liviu Aron told Newsweek. The findings are based on a series of experiments in mice and on analyses of human brain tissue and blood samples from individuals in various stages of cognitive health. Lithium carbonate tablet bottles on shelf. Lithium carbonate tablet bottles on shelf. Getty Images "We found that lithium is uniquely depleted in the brains of people with mild cognitive impairment—a precursor to Alzheimer's. This makes lithium deficiency one of the earliest biochemical signs of the disease, possibly years before clinical symptoms appear," the duo explained. "We also saw that higher endogenous lithium levels were associated with preserved cognitive function even in individuals without Alzheimer's. So, this isn't just about preventing disease—it's about supporting healthy brain aging in general. The new revelation helps to explain why some people with Alzheimer's-like abnormalities in the brain don't go on to develop the disease. While genetic and environmental factors play a role, scientists also haven't been able to suggest why some people with the same risk factors might develop it and others don't—until now. The scientists unearthed that lithium loss in the human brain is one of the earliest changes leading to Alzheimer's. In mice, meanwhile, similar lithium depletion accelerated brain pathology (disease or abnormality) and memory decline. They also found reduced lithium levels stemmed from binding to amyloid plaques (misfolded proteins found between nerve cells found in the brains of people with Alzheimer's) and impaired uptake in the brain. One pair of boxes shows fewer green amyloid clusters on the left and more on the right. Another pair of boxes shows a dim arc of purple and red tau on the left and a... One pair of boxes shows fewer green amyloid clusters on the left and more on the right. Another pair of boxes shows a dim arc of purple and red tau on the left and a brighter arc on the right. More Yankner Lab In their final set of experiments, they found a new lithium compound that avoids "capture" by amyloid plaques restored memory in mice. "In people that start experiencing memory loss, the so-called mild cognitive impairment, lithium gets trapped by amyloid plaques—reducing its availability just when it's most needed to protect against inflammation and neurodegeneration," Yankner and Aron explained. "This creates a self-perpetuating feedback loop of worsening pathology and accelerating disease progression and memory loss." This all ties together decades-long observations in patients and provides a new theory of the disease and strategy for early diagnosis, prevention and treatment, according to the researchers. Recently developed treatments that target amyloid beta (a key component of the amyloid plaques) typically don't reverse memory loss and only modestly reduce the rate of decline. "The idea that lithium deficiency could be a cause of Alzheimer's disease is new and suggests a different therapeutic approach," said Yankner in a statement. Researchers had previously found lithium to be the only metal that had markedly different levels across people with and without Alzheimer's at different stages. But Yankner added in a statement, "Lithium turns out to be like other nutrients we get from the environment, such as iron and vitamin C. "It's the first time anyone's shown that lithium exists at a natural level that's biologically meaningful without giving it as a drug." Previous population studies have shown that higher lithium levels in the environment, including in drinking water, tracked with lower rates of dementia. Woman hugging her elderly mother. Woman hugging her elderly mother. PIKSEL/Getty Images Yankner's team demonstrated in mice that lithium depletion isn't just linked to Alzheimer's, it actually helps drive it. This raises hope that one day lithium could be used to treat the disease in its entirety rather than focusing on a single factor like amyloid beta or tau (another Alzheimer's-associated protein), Yankner said. Crucially, the researchers discovered that as amyloid beta begins to form deposits in the early stages of dementia in both humans and mouse models, it binds to lithium, reducing lithium's function in the brain. The reduced levels of lithium affect all major brain cell types and, in mice, lead to changes similar to those seen in Alzheimer's disease, including memory loss. Treating mice with the most potent amyloid-evading compound, called lithium orotate, reversed Alzheimer's pathology, prevented brain cell damage and restored memory. While the findings need to be confirmed in humans through clinical trials, they suggest that measuring lithium levels could help screen for early Alzheimer's. They also highlight the importance of testing amyloid-evading lithium compounds for treatment or prevention. While other lithium compounds are already used to treat bipolar disorder and clinical depression, they are given at much higher concentrations that can be toxic to some people, the researchers flag. Yankner's team discovered lithium orotate is effective at one-thousandth that dose— enough to mimic the natural level of lithium in the brain. Mice treated for nearly their entire adult lives showed no evidence of toxicity, the study found. If further studies confirm these findings, the researchers say lithium screening through routine blood tests may one day offer a way to identify individuals at risk for Alzheimer's who would benefit from treatment to prevent or delay disease onset. "Our study adds to growing evidence that Alzheimer's may be preventable—with something as simple as keeping brain lithium at healthy levels as we age," said Yankner and Aron. "Clinical trials [on humans] could test the impact of low-dose supplementation on cognitive health and dementia risk." Before lithium is proved to be safe and effective in protecting against neurodegeneration in humans, Yankner emphasized that people should not take lithium compounds on their own. Do you have a health story to share with Newsweek? Do you have a question about Alzheimer's? Let us know via health@ Reference Aron, L., Ngian, Z. K., Qiu, C., Choi, J., Liang, M., Drake, D. M., Hamplova, S. E., Lacey, E. K., Roche, P., Yuan, M., Hazaveh, S. S., Lee, E. A., Bennett, D. A., & Yankner, B. A. (2025). Lithium deficiency and the onset of Alzheimer's disease. Nature.
Boston Globe
5 hours ago
- Boston Globe
New hope for Alzheimer's: Groundbreaking Harvard study finds lithium reverses brain aging
The research suggests a new approach to preventing and treating the mind-robbing disease. Advertisement 'It seems to somehow turn back the clock,' said the team's senior author, Dr. The findings come amid a rising tide of Alzheimer's and growing urgency to pinpoint an effective treatment for the For years, researchers believed the buildup of sticky clumps of protein, known as amyloid plaques, fueled the devastating cascade of brain degeneration in Alzheimer's. But Advertisement Yankner now believes that may be a lithium deficiency. Dr. Bruce Yankner sat in his office at Harvard Medical School next to a photograph of a brain with Alzheimers on Monday, Aug. 4. Heather Diehl/For The Boston Globe Lithium has long been used to treat mental health conditions, particularly bi-polar disorder. But the form of lithium typically used for such treatments, lithium carbonate, is different than the one used by the Yankner team, which employed lithium orotate . His team studied brain tissue donated from about 400 people post mortem, as well as blood samples and a battery of memory tests performed yearly before their death. The participants ranged from cognitively healthy at the time of their death to having full-blown Alzheimer's. The scientists found higher levels of lithium in cognitively healthy people. But as amyloid began forming in the early stages of dementia, in both humans and in mice, the amyloid bound to the lithium, restraining it and reducing its availability to surrounding brain cells. That depleted the lithium even in parts of the brain that were amyloid free, essentially reducing lithium's protective function. To test whether lithium depletion was driving the disease or simply a byproduct of it, they fed healthy mice a lithium-restricted diet, draining their lithium levels. This appeared to accelerate their brain aging process, creating inflammation and reducing the ability of nerve cells to communicate. That spurred memory loss in the mice, as measured by their diminished performance in several laboratory memory tests. The researchers then fed a restricted-lithium diet to mice that were genetically engineered to develop Alzheimer's-like amyloid plaques and abnormal tangles of another protein, called tau, and witnessed a dramatic acceleration of the disease. Advertisement These images show what happens to the brains of Alzheimer's mice when they are placed on a lithium deficient diet. It shows that lithium deficiency markedly increases the number of amyloid plaques and the number of tangle-like structures in the brain, resembling advanced Alzheimer's disease in humans. Yankner Lab But they were able to reverse the disease-related damage and restore memory function, even in older mice with advanced disease, by returning lithium to their diet. (Lithium orotate, the compound the scientists used, can evade capture by Alzheimer's amyloid plaques). These images show that treatment of the Alzheimer mice with a very low dose of lithium orotate almost completely abolishes both the plaques and the tangle-like structures. Yankner Lab Other scientists not involved in the research said the findings create a new approach to designing medications to treat and prevent Alzheimer's. 'This study is looking at it from a novel angle,' said 'I didn't expect that the lithium level [in our body] would be this critical,' she said. 'I just hadn't thought about it this way.' The amount of lithium in medications used for mental health conditions is very high and can be toxic to elderly patients. But the amount of lithium used by Yankner's team was one-thousandth the level, essentially mimicking the amount naturally found in the brain. Indeed, mice fed tiny amounts throughout their adult life showed no signs of toxicity. Earlier research has suggested a link between sustained intake of lithium and lower levels of dementia. Notably, Advertisement 'When we're thinking about the therapeutics of a replacement, if you're lowering something, you just have to replace it back to the natural levels,' he said. 'That seems a lot safer than introducing something that our body is not used to, or doesn't already need in order to function. ' 'That's a really good rationale for pursuing it,' he said. A number of factors are linked through research to a higher risk of Alzheimer's and dementia including advanced age, family history, and genetics, as well as several modifiable factors such as diet, smoking, hypertension and diabetes. Liviu Aron, first author of the study that links lithium deficiency to Alzheimer's disease, looked at samples of human and mouse brains in the Harvard lab on Aug. 4. Heather Diehl/For The Boston Globe Many foods already touted for their health benefits naturally contain higher amounts of lithium — But Kaeberlein and other researchers said the real test of the Harvard team's findings would be a large clinical trial in people, with half of the participants receiving small doses of lithium orotate and the others a sham substance, to compare the findings. Kaeberlein said the safety track record of this form of lithium, which showed no toxicity in animals, may help speed trials in people. Advertisement The Harvard findings 'line up with a lot of earlier work, both in the brain and in normal aging,' Kaeberlein said. And he added something rarely heard from scientists when discussing cutting-edge research and a potential medication that may fundamentally change the course of a dreaded disease. This work, he said, 'feeds my optimism that this will lead to potential therapeutics.' But one obstacle to advancing the research is the freeze on Kay Lazar can be reached at
Yahoo
2 days ago
- Yahoo
2 spacecraft flew exactly in line to imitate a solar eclipse, capture a stunning image and test new tech
During a solar eclipse, astronomers who study heliophysics are able to study the Sun's corona – its outer atmosphere – in ways they are unable to do at any other time. The brightest part of the Sun is so bright that it blocks the faint light from the corona, so it is invisible to most of the instruments astronomers use. The exception is when the Moon blocks the Sun, casting a shadow on the Earth during an eclipse. But as an astronomer, I know eclipses are rare, they last only a few minutes, and they are visible only on narrow paths across the Earth. So, researchers have to work hard to get their equipment to the right place to capture these short, infrequent events. In their quest to learn more about the Sun, scientists at the European Space Agency have built and launched a new probe designed specifically to create artificial eclipses. Meet Proba-3 This probe, called Proba-3, works just like a real solar eclipse. One spacecraft, which is roughly circular when viewed from the front, orbits closer to the Sun, and its job is to block the bright parts of the Sun, acting as the Moon would in a real eclipse. It casts a shadow on a second probe that has a camera capable of photographing the resulting artificial eclipse. Having two separate spacecraft flying independently but in such a way that one casts a shadow on the other is a challenging task. But future missions depend on scientists figuring out how to make this precision choreography technology work, and so Proba-3 is a test. This technology is helping to pave the way for future missions that could include satellites that dock with and deorbit dead satellites or powerful telescopes with instruments located far from their main mirrors. The side benefit is that researchers get to practice by taking important scientific photos of the Sun's corona, allowing them to learn more about the Sun at the same time. An immense challenge The two satellites launched in 2024 and entered orbits that approach Earth as close as 372 miles (600 kilometers) – that's about 50% farther from Earth than the International Space Station – and reach more than 37,282 miles (60,000 km) at their most distant point, about one-sixth of the way to the Moon. During this orbit, the satellites move at speeds between 5,400 miles per hour (8,690 kilometers per hour) and 79,200 mph (127,460 kph). At their slowest, they're still moving fast enough to go from New York City to Philadelphia in one minute. While flying at that speed, they can control themselves automatically, without a human guiding them, and fly 492 feet (150 meters) apart – a separation that is longer than the length of a typical football stadium – while still keeping their locations aligned to about one millimeter. They needed to maintain that precise flying pattern for hours in order to take a picture of the Sun's corona, and they did it in June 2025. The Proba-3 mission is also studying space weather by observing high-energy particles that the Sun ejects out into space, sometimes in the direction of the Earth. Space weather causes the aurora, also known as the northern lights, on Earth. While the aurora is beautiful, solar storms can also harm Earth-orbiting satellites. The hope is that Proba-3 will help scientists continue learning about the Sun and better predict dangerous space weather events in time to protect sensitive satellites. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Christopher Palma, Penn State Read more: What would a solar eclipse look like from the Moon? An astronomer answers that and other total eclipse questions Solar eclipses result from a fantastic celestial coincidence of scale and distance Total eclipse, partial failure: Scientific expeditions don't always go as planned Christopher Palma does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
