Europe's ExoMars Trace Gas Orbiter (TGO) spacecraft spotted a possible signal of hydrogen chloride gas leaking from rifts in the region of Alba Mons, the largest volcano on Mars in terms of surface area. (Mars' famous Olympus Mons is the largest volcano in terms of height.) Scientists interpret this gas as emissions from hot magma below the regolith of Mars.

Although more research is required to confirm the emissions, the team suggested that Alba Mons may host an environment similar to hydrothermal vents on Earth, where life once likely arose and continues to thrive today.

The study, published in the journal Science Advances Wednesday (Nov. 4), is not the first to suggest that magma may be flowing on Mars; NASA's InSight lander interpreted its presence through seismic observations and modeling earlier this year. But the new findings are the strongest evidence yet of gases being released by dormant volcanoes on Mars, first study author Alexander Trokhimovskiy, at Russia's Space Research Institute, told Live Science.

"Our study offers a complementary and potentially independent line of evidence [of Martian magma]: Atmospheric observations that reveal a possible signature of gas release from a subsurface magmatic system," Trokhimovskiy wrote in an email.

Europe smelt it — but what dealt it?

TGO first detected hydrogen chloride gas in Mars' atmosphere in 2021, but scientists were hesitant to link it to volcanic activity. The gas appeared to be seasonal, its distribution was not localized at a possible volcanic region, and other signs of volcanic gases, like sulfur, were not present, study co-author Kevin Olson, a visiting researcher at the University of Oxford who studies Mars gases, told Live Science in a separate email.

Further work, however, suggested that the gas wasn't just popping up in the warmer spring and summer in Mars' southern hemisphere; it also appeared in the winter in the northern hemisphere, he noted.

"I managed to catch two observations from the start of northern winter in the first Mars year of our mission, and a single observation the next year," Olson said, adding that a year on Mars is closer to two years on Earth due to the planet's wider orbit. "These out-of-season measurements were close to one another in location and time in both years, which was rather surprising. We then set about creating a campaign of special, targeted measurements at this time and place."

That campaign lasted two Mars years — roughly four Earth years — and increased the likelihood that scientists are seeing "an injection" of hydrogen chloride into the atmosphere from volcano-adjacent vents, Olson said.

The scientists confirmed the unseasonal observations in the northern hemisphere, finding a "distinct and pronounced signal" that then diminishes and falls below the spacecraft's detection threshold. "This inconsistency is more suggestive of a puff of gas entering the atmosphere than of regular atmospheric chemistry," he said. "While the link remains a hypothesis, we have now seen this gas appear locally, and nowhere else, over four Mars years of observations."

Daniel Mège, also a co-author of the paper and a professor who studies planetary geology at the Polish Academy of Sciences, identified the fissures where the gas may be emerging. He said the complementary evidence from InSight (on the ground) and TGO (circling above) helps give the study weight: InSight spotted activity in the crust, while TGO detected the emissions in the atmosphere.

Although magma activity is not in itself a sign of life, Mège noted that Earth's first life-forms came from sites like hydrothermal zones, which have a similar confluence of materials and energy as the potential vents on Mars. But conditions would need to be favorable in that area for at least millions of years to allow life to form, he cautioned.

"If these requirements are met at local scale, at the scale of the seepage structures, then living organisms might wait for us to discover them," he told Live Science in an email. "But maintaining stable conditions over such a long period at a very local scale is not obvious."

What do you know about the Red Planet? Test your knowledge with our Mars quiz!

'> Scientists find the best evidence yet of potentially habitable volcanic vents on Mars Nicholas Jakubovics, an oral microbiologist at Newcastle University in the U.K. who was not involved in the study. "The idea that the toothbrush surface itself is actively doing something is really interesting."

The experimental brush has bristles made from polyvinylidene fluoride (PVDF), a plastic that generates electricity when bent; these types of energy-producing materials are called piezoelectric. As the bristles flex during brushing, they produce an electrical charge that then triggers chemical reactions in saliva and water. These reactions release reactive oxygen species (ROS), which are highly reactive molecules that can damage bacterial cells.

Even when the bristles are not being used to brush, they carry a faint surface charge that helps prevent bacteria from clinging to the brush head when the toothbrush isn't in use, the team reported Wednesday (Nov. 4) in the journal Science Advances.

In laboratory tests where the toothbrush was used on isolated germs, its electrified bristles killed more than half of the Streptococcus mutans bacteria present. These microbes contribute to tooth decay. By comparison, nylon bristles killed just 9% of the bacteria. They also reduced levels of Porphyromonas gingivalis, a bacterium linked to gum disease, by up to 78%, while nylon brushes reduced them by less than 8%.

When the researchers added an antioxidant — a compound that neutralizes ROS — the new toothbrush's antibacterial effect largely disappeared, highlighting that the ROS are likely the key to its effects.

The team also found that the activity of certain genes in both S. mutans and P. gingivalis fell after exposure to the electrified bristles. These genes are involved in making ATP-binding cassette (ABC) transporters — molecular pumps that help shuttle essential nutrients across bacterial cell membranes. The researchers suspect that disrupting this machinery makes it harder for these microbes to survive and cling to teeth.

But Jakubovics was not convinced by that part of the team's explanation. "ABC transporters transport all sorts of different things," he said, adding that the findings did not clearly show how changes in these genes affected the bacteria.

The researchers also tested the new brush against plaque biofilms — hardy communities of bacteria that stick together and cling to tooth surfaces. For the experiment, they grew human dental plaque on cow tooth enamel and found that the brush removed more than 99% of the biofilm, outperforming a regular nylon brush.

Finally, the team moved to humans, putting the brush to the test in 115 adults with gum inflammation or tooth decay. These study participants were randomly assigned to use either the new toothbrushes or traditional nylon-bristled brushes twice a day for three months. (The study didn't note whether participants noticed a difference in sensation when using the electrified brushes.)

By the end of the trial, the participants who used the electrified bristles had less plaque, less gum inflammation and less bleeding than the participants who used ordinary brushes. Plaque samples also showed that the people who used electrified brushes had lower levels of bacteria associated with oral disease and higher levels of beneficial bacteria, which have previously been reported to suppress harmful oral bacteria and support oral health.

The researchers think that the disease-linked bacteria may have relatively fragile cell membranes, making them more vulnerable to damage from ROS than the beneficial bacteria. That's a theory that requires further study, though, so it's not completely clear how selective the brush is against plaque-causing bacteria.

In a test of the toothbrush's durability, the PVDF bristles retained their structure and electrical properties over three months of simulated use. Lab-grown mouse cells repeatedly exposed to brush material showed no signs of damage, and brushing on cow tooth enamel did not increase surface roughness. However, these tests cannot establish whether repeated use of these brushes is safe for humans.

"We would want to make sure that it is safe on the tissues for long-term use," Jakubovics said. He noted that, in lab tests, bacteria are grown directly on the bristles and exposed to their electricity for hours, "whereas in reality, in the mouth, your bristle is only in contact with the tooth or oral tissue for a very short time."

The trial with humans provides some insight into how the brush works in real life, but it was relatively small. Larger studies will be needed to find out whether the toothbrush offers a meaningful advantage over conventional brushes. For now, Jakubovics sees the recent study as just a proof of concept; more information and more convincing clinical data are still needed, he emphasized.

This article is for informational purposes only and is not meant to offer medical advice.

'> This self-powered toothbrush makes electricity to kill cavity-causing bacteria

Although the Southern Taurids are a minor meteor shower that produces only a handful of "shooting stars" each hour, it occasionally features exceptionally bright meteors called fireballs, which can briefly light up the night sky. According to NASA, fireballs are meteors at least as bright as Venus.

The Southern Taurids are active for several weeks in fall and peak Oct. 14, but the American Meteor Society expects the "fireball swarm component" to peak around Nov. 4-5.

Meteors can streak across any part of the sky, but for this meteor shower, they appear to radiate from the constellation Taurus, which will rise in the eastern sky as night falls and climb higher as the night progresses. That makes the hours around midnight a good time to look for shooting stars. However, unlike major meteor showers such as the Perseids (which peak Aug. 12-13) and the Geminids (which peak Dec. 13-14), the Southern Taurids have a broad peak, so there's no need to be outside at an exact time.

The Southern Taurids are the first of two fireball-rich meteor showers to be visible this month. The Northern Taurids will peak overnight on Nov. 11-12, giving stargazers another chance to spot a fireball. Both meteor showers result from dust and debris left in the inner solar system by Comet 2P/Encke striking Earth's atmosphere.

Discovered in 1786, Encke is a massive comet, measuring 2.98 miles (4.8 kilometers) in diameter, according to NASA ‪—‬ around one-third the size of the object thought to have killed the nonavian dinosaurs. Encke orbits the sun every 3.3 years, one of the shortest known orbital periods of any comet in the solar system. Scientists theorize that Encke is one of many fragments of a giant comet that broke apart 20,000 to 30,000 years ago.

After the Southern and Northern Taurids, the next meteor shower will be the Leonids, which peak Nov. 17-18 and produce around 15 shooting stars per hour, and the Geminids, which peak Dec. 13-14 and can deliver up to 120 shooting stars per hour close to the peak.

It's best to watch meteor showers with the naked eye, but a good backyard telescope will serve you well in the months to come. As the long nights of winter kick off in the Northern Hemisphere, skywatching opportunities abound — including four consecutive supermoons from Nov. 2026 to Feb. 2027.

'> Southern Taurid meteor shower could bring fireballs ‪this week —‬ when and where to look

On Oct. 27, a 19.6-foot-long (6 meters) skeleton of Nanotyrannus lancensis known as "Jodi" was sold at Sotheby's in New York for $47,255,000, far exceeding its $6 million to $9 million estimate. The buyer and seller were not identified. It was the latest in a string of multimillion-dollar dinosaur auctions, following the $50.1 million sale of a T. rex (Gus) in July and the $44.6 million sale of a Stegosaurus (Apex) in 2024.

Fossils like Jodi, Apex, and Gus belong in public collections, where they can contribute to science and remain accessible for future generations. Not in the hands of private collectors.

There are three main reasons why. First: Fossils are evidence, not objects. A dinosaur's bones can reveal how it grew, moved, fed, and lived. They preserve traces of injury and disease, help reconstruct ancient ecosystems, and offer clues about the "rules of life" governing our world that scientists are still learning to interpret.

Jodi illustrates exactly why access to physical evidence matters. For nearly half a century, paleontologists debated whether Nanotyrannus was a distinct dinosaur or simply a juvenile T. rex. A lack of well-preserved fossils available for study only fueled the uncertainty. And then a remarkable specimen, once in private hands, moved into the public trust.

The fossil was uncovered in Montana in 2006 alongside a Triceratops. Dubbed the "Dueling Dinosaurs," it took until 2022, and an appeal in the state's Supreme Court, for the remains to be acquired by the Museum of Natural Sciences so they could be fully studied. This research provided a powerful new perspective, arguing that Nanotyrannus lancensis was a distinct dinosaur and, moreover, that a second species of Nanotyrannus once roamed the American West.

This hypothesis has big implications for the health of ecosystems before one of Earth's most severe extinction events — but it currently rests on the scant few Nanotyrannus specimens housed in public collections. Specimens like Jodi could uphold or dethrone it. Without access, we, and Jodi’s true identity, will remain in the dark.

It is hard to overstate the irony of Jodi's sale: a specimen recently listed as a juvenile T. rex now captures the world's imagination, and commands double the price tag, as a "Nanotyrannus." Yet if a similar fate had befallen the Dueling Dinosaurs and they had remained in private hands, we would not have known for certain that Nanotyrannus ever existed.

Scientific progress depends on researchers being able to compare specimens, test hypotheses, and revisit earlier conclusions. When access relies on a private owner's permission, repeatability is not assured, and science cannot proceed. A specimen might be available today but inaccessible tomorrow. This is why access to the evidence must endure.

This brings us to the second problem with privately owned dinosaurs. Digital scans cannot replace the original fossil.

Three-dimensional scans and digital models are powerful tools. We use them to measure bones, compare anatomy, share information, and educate the public. But digital models capture only the most superficial aspects of a fossil's story.

To understand dinosaur growth, we examine microscopic structures inside fossilized bone through a technique called bone histology. We also analyze the chemistry of fossils to investigate diet, migration patterns, and metabolism. Such work requires physical samples, not just images of a bone's surface. We also need contextual data about the surrounding sediments, preservation mode, and ancient environment in order to explore questions about the ecosystems in which the animals once lived. Much of this information is lost in the rush to excavate and prepare fossils as quickly as possible for the auction block. It can never be reclaimed.

We cannot predict what novel technologies future researchers will employ to make new discoveries from old bones, or even which questions they will ask. Technology will continue to advance, bringing analytical methods we cannot anticipate. A scan made today does not guarantee that researchers will have the physical evidence needed for tomorrow's discoveries. Digital access should complement preservation of original specimens, not justify losing it.

Finally, private ownership cannot guarantee lasting public access. Yes, some private collectors financially support research and education and donate specimens they purchase. Those contributions are valuable. But the issue is not whether an individual owner is generous; it is whether access is guaranteed over time.

A temporary loan is insufficient. A loaned specimen can be withdrawn, sold, or inherited by someone with different priorities, situations that are becoming increasingly common in the U.S. and abroad. By contrast, a fossil deposited in a responsible public research institution is documented, cared for, studied, and made available to future researchers and educators in perpetuity. The question is not whether people should be able to admire dinosaurs; it is whether the evidence that helps us understand them will remain available to everyone.

Nor should museums consider selling scientifically important fossils to cover operating shortfalls. Collections are not ordinary financial assets to liquidate when budgets tighten. Selling an irreplaceable specimen provides a one-time payment while sacrificing future scientific potential. Museums need sustainable funding for collections care, research, and education, not pressure to trade away the very resources they exist to preserve.

Jodi's sale is complete, but the fossil's long-term future remains uncertain. With the buyer's identity undisclosed, the public cannot know what arrangements, if any, will ensure continued access for researchers and educators. We hope the new owner will make Jodi available for scientific study and public education, through permanent placement in a public research institution. But hope is not a substitute for a guarantee.

There is a better way to support paleontology. Enthusiasts who want to share in the excitement of discovery can fund fieldwork and research, endow curatorial positions, strengthen museum collections, or donate important fossils to public institutions where we can all learn from them.

Dinosaurs inspire wonder because they connect us to a world vastly different from our own. But their importance extends far beyond their power to captivate us. They are part of our shared natural heritage and an irreplaceable record of Earth's history.

We should measure a dinosaur's worth not by the price it commands at auction, but by the knowledge it can help us build, and by whether we preserve that opportunity for generations to come. Earth's history belongs to all of us, not to the highest bidder.

Editor's note: This article was updated on Nov. 4 at 8.22 a.m. ET to correct the year the Museum of Natural Sciences acquired the Dueling Dinosaurs.

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'> When dinosaurs are sold to the highest bidder, we all lose

The feelings would end abruptly when she finished breastfeeding and then appear again the next time she was about to release milk, according to a report of the case, which the patient co-authored. The patient was a breastfeeding counselor for the United States Department of Agriculture Women, Infants, and Children (WIC) Program.

Until the baby was about 18 months old, this phenomenon would happen every time the woman breastfed — about five times per day, on average. Unlike postpartum depression,‬ which can cause persistent feelings of despondency, anxiety and mood swings in new parents,‬ the woman felt "helpless, hopeless, [and] worthless" only during her milk release. She reported that she otherwise felt happy and bonded with her new baby.

What happened next: When her baby was 7 months old, the woman began meeting with a lactation consultant, who later co-authored the case report. They worked together to track the mother's symptoms over time, noting when negative feelings began and if any intervention made them subside or worsen.

The diagnosis: Because the woman's condition did not have a formal name at the time, she began calling it "dysphoric milk ejection reflex," or D-MER.

The case report authors initially suspected that fluctuations in the woman's oxytocin levels might be causing D-MER, since the hormone is released into the bloodstream prior to the milk ejection reflex during breastfeeding. However, external factors that are known to affect oxytocin levels, such as tobacco use, did not always trigger the woman's symptoms.

Next, they looked at dopamine. The chemical messenger's fluctuations during breastfeeding are less studied than those of oxytocin and prolactin, another hormone linked to lactation. However, dopamine levels have otherwise been connected to strong emotional responses. Activities that seemed to ease the patient's D-MER symptoms — such as taking the cold medication pseudoephedrine, smoking cigarettes or binging on chocolate ice cream — are also known to increase dopamine levels. Meanwhile, acute stress, which reduces dopamine, worsened her symptoms.

The authors hypothesized that an abrupt drop in dopamine prior to milk release might be a trigger for D-MER.

The treatment: The woman began taking bupropion (better known by the brand name Wellbutrin), an antidepressant that increases the amount of dopamine in the brain. She saw a dramatic reduction in her D-MER symptoms within a day, and five days later, her symptoms were almost entirely gone.

However, she stopped taking the drug after a few weeks due to unwanted side effects (which aren't described in the report), and the symptoms came back. She then tried an herbal remedy containing roseroot (Rhodiola rosea), a plant historically used in some places to manage depression. Some recent studies suggest that compounds in R. rosea interact with receptors for chemical messengers in the brain; however, there is little reliable evidence demonstrating its purported therapeutic benefits, according to the National Center for Complementary and Integrative Health.

She took R. rosea three to four times per day, reporting that her symptoms became "much milder" but returned if she skipped a day. As her daughter grew older and the woman breastfed less often, the woman stopped taking the supplement. When the child was 3 years old and no longer breastfeeding, the woman's D-MER symptoms went away entirely.

What makes the case unique: Prior to this report, published in 2011, D-MER was not widely recognized or documented in the scientific literature, and there was no research into its causes or treatment.

The patient and co-author of the report created the website D-MER.org in 2007 to share information about the condition more widely. She hoped to raise awareness among medical professionals and to help breastfeeding people who experience this condition by providing resources and support and encouraging them to understand that what they were feeling was a physiological side effect of nursing. Since the site's launch, hundreds of visitors have described having negative feelings while breastfeeding, according to the report.

Over the past two decades, more case reports describing the condition have been published. In a 2025 paper in the European Journal of Obstetrics & Gynecology and Reproductive Biology, researchers estimated that roughly 14.2% of lactating parents experience D-MER and that 1 in 6 stop breastfeeding as a result. Dopamine is thought to play a part, but the exact cause of D-MER has not been definitively established in peer-reviewed research yet.

There is no definitive treatment for D-MER, although some have anecdotally found relief through techniques for stress reduction, such as meditation and breathing exercises, and by seeking support from partners, friends and breastfeeding groups online.

Short-lived negative feelings resembling D-MER have also been reported in people who are not lactating. These anecdotal accounts describe intense, negative feelings brought on by nipple stimulation. One online discussion group referred to this phenomenon as "sad nipple syndrome," according to the authors of the case report. As with D-MER, dopamine may play a part, but the overall neurochemistry underlying that emotional response is unknown.

Breastfeeding and parenthood can be an emotional roller coaster even under the best circumstances, the authors noted. In that sense, they explained, people with D-MER have "the same emotional peaks and valleys" as all new parents do. Yet the negative feelings that accompany D-MER are nonetheless different from the normal range of emotions in the parents of newborns, and they can cause extreme distress if they are not correctly identified and addressed as being specific to breastfeeding.

People with D-MER, the authors concluded, "serve as a reminder to us all that we do not yet have a complete understanding of human lactation."

For more intriguing medical cases, check out our Diagnostic Dilemma archives.

This article is for informational purposes only and is not meant to offer medical advice.

Can you guess the diagnosis in these strange medical cases? Find out with our diagnostic dilemma quiz!

'> Mom experienced 'extreme unhappiness' only when she breastfed