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From a new Jasper Fforde to post-apocalyptic hellscapes aplenty, February’s science fiction offers something for everyone

Tiny male anglerfish fuse their bodies into the larger females, and this strange strategy may have helped the fish diversify widely in the deep sea

The human colon may represent the most biodense ecosystem in the world. Though many may believe that our stool is primarily made up of undigested food, about 75 percent is pure bacteria—trillions and trillions, in fact, about half a trillion bacteria per teaspoon.

Do we get anything from these trillions of tenants taking up residence in our colon, or are they just squatting? They pay rent by boosting our immune system, making vitamins for us, improving our digestion, and balancing our hormones. We house and feed them, and they maintain and protect their house, our body. Prebiotics are what feed good bacteria. Probiotics are the good bacteria themselves. And postbiotics are what our bacteria make.

Our gut bacteria are known as a “forgotten organ,” as metabolically active as our liver and weighing as much as one of our kidneys. They may control as many as one in ten metabolites in our bloodstream. Each one of us has about 23,000 genes, but our gut bacteria, collectively, have about three million. About half of the cells in our body are not human. We are, in effect, a superorganism, a kind of “human-microbe hybrid.”

Having coevolved with us and our ancestors for millions of years, the relationship we have with our gut flora is so tightly knit as to affect most of our physiological functions. Yet our microbiome is probably the most adaptable component of our body. Gut bugs like Escherichia coli (E. coli) can divide every twenty minutes. The more than ten trillion bugs we churn out every day can therefore rapidly respond to changing life conditions. Every meal, we have the opportunity to nudge them in the right direction.

Thousands of years ago, Hippocrates is attributed as saying that all diseases begin in the gut or, more ominously, “death sits in the bowels.” Of course, he also thought women were hysterical because of their “wandering uterus.” (“Hysteria” comes from the Greek husterikos for “of the womb.”) So much for ancient medical wisdom. The pendulum then swung to the point of incredulity when the medical community refused to accept the role of one gut bug, Helicobacter pylori, as the cause of stomach and intestinal ulcers. Out of frustration, one of the pioneers chugged a brew of the bugs from one of his ulcer patients to prove the point, before finally being vindicated with the Nobel Prize in 2005 for his discovery.

In some ways, the pendulum has swung back, with overstated causal claims about the microbiome’s role in a wide range of disparate diseases that are casually bandied about. Perhaps the boldest such claim dates back more than a century to Élie Metchnikoff, who argued that senility and the disabilities of old age were caused by “putrefactive bacterial autotoxins” leaking from the colon. He was the first to emphasize the importance of the gut microbiome to aging. He attributed healthy aging to gut bacteria that fermented carbohydrates into beneficial metabolic end products like lactic acid and associated unhealthy aging with putrefaction, the process in which bacteria degrade protein into noxious metabolites as waste products.

There is no shortage throughout history of oldtimey crackpots with quack medical theories, but Metchnikoff was no slouch. He was appointed Louis Pasteur’s successor, coined the terms “gerontology” and “probiotics,” and won the Nobel Prize in medicine to become the founding “father of cellular immunology.” More than a century later, some aspects of his theories on aging and the gut are now being vindicated.

Young at Gut

Full-term, vaginally delivered, breastfed babies are said to start out with the gold standard for a healthy microbiome, which then starts to diverge as we age. The microbiomes of children, adults, the elderly, and centenarians tend to cluster together, such that a “microbiomic clock” can be devised. Dozens of different classes of bacteria in our gut so reliably shift as we age that our age can be guessed based on a stool sample within about a six-year margin of error. If these changes turn out to play a causal role in the aging process, then, hypothetically, our future high-tech toilet may one day be able predict our lifespan as well.

The transition from adulthood into old age is accompanied by pronounced changes to the microbiome. Given large interpersonal differences, there is no “typical” microbiome of the elderly, but the trends are in the very direction Metchnikoff described: a shift from the fermentation of fiber to the putrefaction of protein. This deviation from good bugs to bad is accompanied by an increase in gut leakiness, the spillage of bacterial toxins into the bloodstream, and a cascade of inflammatory effects. This has led to the proposal that this microbiome shift is a “primary cause of aging-associated pathologies and consequent premature death of elderly people.”

The most important role a healthy microbiome has for preserving health as we age is thought to be the prevention of systemic inflammation.

As profound a change in microbiome composition from early adulthood into old age, there’s an even bigger divergence between the elderly and centenarians. When researchers analyzed centenarian poop, they found a maintenance of short-chain fatty acid production from fiber fermentation. For example, in the Bama County longevity region in the Guangxi province of China, fecal sample analyses found that centenarians were churning out more than twice as much butyrate as those in their eighties or nineties living in the same region. Butyrate is an anti-inflammatory short-chain fatty acid critical for the maintenance of gut barrier integrity. At the same time, there were significantly fewer products of putrefaction, such as ammonia and uremic toxins like p-cresol. The researchers concluded that an increase of dietary fiber intake may therefore be a path toward longevity. An abundance of fiber feeders also distinguished healthy individuals ninety years and older from unhealthy nonagenarians.

Centenarian Scat

Interestingly, the microbiomes of Chinese centenarians shared some common features with Italian centenarians, suggesting that there could be certain universal signatures of a longevity-promoting microbiome. For example, centenarians have up to about a fifteenfold increase in butyrate producers.

A study of dozens of semi-supercentenarians (those aged 105 to 109) found higher levels of health-associated bacteria, such as Bifidobacteria and Akkermansia. In vaginally delivered, breastfed infants,

Bifidobacteria make up 90 percent of colon bacteria, but the level may slip down to less than five percent in adult colons and even less in the elderly and those with inflammatory bowel disease. But centenarians carry more of the good bacteria in their gut.

Bifidobacteria are often used as probiotics, but anti-aging properties may exist in their postbiotics. Bifidobacteria are one of the many bacteria that secrete “exopolysaccharides,” a science-y word for slime. That’s what dental plaque is—the biofilm created by bacteria on our teeth. Exopolysaccharides produced from a strain of Bifidobacteria isolated from centenarian poop were found to have anti-aging properties in mice, reducing the accumulation of age pigment in their brains and boosting the antioxidant capacity of their blood and livers.

Akkermansia muciniphila is named after the late Dutch microbiologist Antoon Akkermans and from Latin and Greek for “mucus-lover.” The species is the dominant colonizer of the protective mucus layer in our gut that is secreted by our intestinal lining. Unfortunately, that mucus layer thins as we age, a problem exacerbated by low-fiber diets. When we eat a fiber-depleted diet, we starve our microbial selves. Our famished flora, the microbes in our gut, have to then compete for limited resources and may consume our own mucus barrier as an alternative energy source, thereby undermining our defenses. Mucus erosion from bacterial overgrazing can be switched on and off on a day-to-day basis in mice supplanted with human microbiomes with fiber-rich and fiber-free diets. You can even show it in a Petri dish. Researchers successfully recreated layers of human intestinal cells and showed that dripping fiber (from plantains and broccoli) onto the cells at dietary doses could “markedly reduce” the number of E. coli bacteria breaching the barrier. Aside from eating fiber-rich foods, A. muciniphila helps to directly restore the protective layer by stimulating mucus secretion.

A. muciniphila is a likely candidate for a healthy aging biomarker, as its abundance is enriched in centenarians and it is particularly scarce in elders suffering from frailty. A comparative study was undertaken of the microbiomes of people in their seventies and eighties experiencing “healthy” versus “non-healthy” aging, defined as the absence or presence of cancer, diabetes, or heart, lung, or brain disease. Akkermansia, the species most associated with healthier aging, were three times more abundant in the fecal samples of the healthy versus non-healthy aging cohort. Among centenarians, a drop in A. muciniphila is one of the microbiome changes that seems to occur about seven months before death, despite no apparent changes in the physical status, food intake, or appetite at the time. To prove a causal role in aging, researchers showed that feeding A. muciniphila to aging-accelerated mice significantly extended their lifespans.

Cause, Consequence, or Confounding

A recurring recommendation from centenarian poop studies is the promotion of high-fiber diets, one of the most consistently cited pieces of lifestyle advice in general for extreme longevity and health. An alternative proposal is a fecal transplant, from a cocktail of centenarian stool. Both approaches assume a cause-and-effect relationship between fiber-fueled feces and long lives, but there remains much controversy over whether age-related microbiome changes are cause, consequence, or confounding.

Aging is accompanied by dysbiosis, an unhealthy imbalance of gut flora characterized by a loss of fiber-fed species. Rather than a changing microbiome contributing to the aging process, it’s easier to imagine how aging could instead be contributing to a changing microbiome. Loss of taste, smell, and teeth with age could lead to decreased consumption of fiber-rich foods, replaced by salted, sweetened, easier-to-chew processed foods. The drop in the quantity and diversity of whole plant foods—the only naturally abundant source of fiber—could result in a dysbiosis that leads to early death and disability. Or, the decline in diet quality could directly dispose to disease, with the dysbiosis just an incidental marker of an unhealthy diet.

There are also ways aging can be connected to dysbiosis independent of diet. While the rates of antibiotic prescriptions in childhood and through middle age have dropped in recent years, prescription rates among the elderly have shot up. Even non-antibiotic pharmaceuticals can muck with our microbiome. A study pitting more than a thousand FDA-approved drugs against forty representative strains of gut bacteria found that 24 percent of marketed drugs inhibited the growth of at least one strain. Reduced physical activity could also contribute to sluggish, stagnant bowels that could leave our gut bugs no other choice but to turn to protein for putrefaction once preferred prebiotics are used up. Nursing home residents are often fed the kind of low-fiber diet that can contribute to the “decimation” of a healthy microbiome.

This article appeared in Skeptic magazine 28.4
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So, while researchers have interpreted the link between dysbiosis and frailty as a poor diet leading to poor gut flora leading to poor health, the arrows of causality could potentially go in every which direction. Maybe there’s even a chicken-or-the-egg feedback loop in play. With so many interrelated factors, you can imagine how hard it is to tease out the causal chain of events.

These questions crop up all the time in microbiome research. For example, the microbiomes of centenarians aren’t just better at digesting fiber. They’re better at detoxifying industrial pollutants, such as petrochemicals; food preservatives like benzoate and naphthalene, used in petroleum refinement; and haloalkanes, widely used commercially as flame retardants, refrigerants, propellants, and solvents. None of these detoxification pathways was found in the microbiomes of the Hadza, one of the last hunter-gatherer tribes in Africa. Did the enhanced detoxification in centenarian guts (compared to younger individuals) contribute to their longevity, or did their longevity contribute to their enhanced detoxification (given their longer lifetime exposure and accumulation of chemicals)?

The microbiomes of centenarians and semi-supercentenarians are better able to metabolize plant fats than animal fats, but maybe that’s just due to their eating more plant-based diets. The Bama County longevity region centenarians who had such an abundance of fiber feeders were eating more than 70 percent more fiber (38 g versus only 22 g per 2,000 calories) compared to those aged eighty through ninety-nine living in the same region. The only way to know if their longer lives eating more healthfully just led to a better microbiome or if their better microbiome actually contributed to their living longer is to put it to the test.

Fecal Transplant Experiments

Longevity researchers have good reason to suspect a causal, rather than bystander, role for age-related microbiome changes, given fecal transplant studies showing that the lives of old animals can be extended by receiving gut bugs from younger animals. Centenarian stool has anti-aging effects when fed to mice. Researchers fed mice fecal matter from a 70-year-old individual that contained Bilophila wadsworthia, a pro-inflammatory bacteria enriched by a diet high in animal products, versus feces from a 101-year-old containing more fiber feeders. Mice transplanted with the centenarian microbiome ended up displaying a range of youthful physiological indicators, including less age pigment in their brains. This raises the possibility that we will one day be using centenarian fecal matter to promote healthy aging. Why bathe in the blood of virgins when you can dine on the dung of the venerable?

Plugging Leaks with Fiber

One of the mechanisms by which intestinal dysbiosis may accelerate aging is a leaky gut. This can lead to tiny bits of undigested food, microbes, and toxins slipping through our gut lining and entering uninvited into our bloodstream, triggering chronic systemic inflammation. Thankfully, there’s something we can do about it.

To avoid gut dysbiosis, inflammation, and leakiness, plants should be preferred. The reason vegetarians tend to have a better intestinal microbiome balance, a high bacterial biodiversity, and enhanced integrity of the intestinal barrier, and also produce markedly less uremic toxins in the gut, is likely that fiber is the primary food for a healthy gut microbiome. Cause and effect was established in a randomized, double-blind, crossover study of pasta with or without added fiber.

Dysbiosis Inflammation Immunosuppression

The most important role a healthy microbiome has for preserving health as we age is thought to be the prevention of systemic inflammation. Inflammaging is a strong risk factor not only for premature death. Those with higher-than-average levels of inflammatory markers in their blood for their age are more likely to be hospitalized, frail, and less independent, and suffer from a variety of diseases, including common infections.

In Japan, for example, more than 40 percent of all centenarian deaths are due to pneumonia and other infectious diseases. In one of the largest studies, involving nearly 36,000 British centenarians, pneumonia was the leading identifiable cause of death. Inflammaging has not only been shown to increase susceptibility to coming down with the leading cause of bacterial pneumonia but older adults with more inflammation also tend to suffer increased severity and decreased survival.

As we age, our immune system macrophages (from the Greek for “big eaters”) start to lose their ability to engulf and destroy bacteria. The same happens in regular mice. But mice raised microbe-free don’t suffer from the leaking gut, subsequent inflammation, and loss of macrophage function. To connect the dots between the inflammation and loss of function, researchers found that the macrophage impairment could be induced in microbe-free mice by infusing them with an inflammatory mediator, which, when dripped on macrophages in a Petri dish, could directly interfere with their ability to kill pneumonia bacteria. Because our immune system is also responsible for cancer defense, immune dysfunction caused by the inflammation resulting from dysbiosis may also help explain why cancer incidence increases so steeply as we age (and why microbe-free mice have fewer tumors and live longer).

Avoiding Dietary Antibiotics

Other than getting enough fiber, what else can we do to prevent dysbiosis in the first place? There are a number of factors that contribute to microbiome imbalance. For example, on any given day, an average of about two and a half doses of antibiotics are consumed for every one hundred people in Western countries. The havoc this can play on our microbiome may explain why antibiotic use predicts an increased risk of cancer, though confounding factors, such as smoking, that are associated with both, could also potentially explain this link.

Up to three-quarters of antibiotic use is of questionable therapeutic value. Avoiding unnecessary use of antibiotics and using targeted, narrow-spectrum agents whenever possible can help protect our gut flora, but most people may not realize they’re consuming antibiotic residues every day in the meat, dairy, and eggs they eat. As much as 80 percent of the antibiotics used in the United States doesn’t go to treat sick people but rather is fed to farm animals in part as a crutch to compensate for the squalid conditions that now characterize much of modern agribusiness. But do enough antibiotics make it onto our plates to make a difference?

Infections with multidrug-resistant bacteria are on target to become the world’s leading cause of disease and death by the year 2050, poised to surpass even cancer and heart disease. Excessive antibiotic use can result in our guts becoming colonized with these superbugs, so researchers set out to calculate how many animal products one would need to eat to achieve antibiotic concentrations in our colon to give resistant bugs an advantage. Single servings of beef, chicken, or pork were found to contain enough tetracycline, ciprofloxacin, tilmicosin, tylosin, sarafloxacin, and erythromycin to favor the growth of resistant bacteria. One and a half servings of fish (150 g) exceeded minimum selective concentrations of ciprofloxacin and erythromycin. Two cups of milk could tip the scales for tetracycline, ciprofloxacin, tilmicosin, tylosin, and lincomycin. And, legal levels of erythromycin and oxytetracycline in two eggs could also exceed safe levels.

We need to stop squandering lifesaving miracle drugs just to speed the growth of farm animals reared in unhygienic conditions, and we also need to stop the reckless overuse in medicine.

Excerpted from How Not to Age: The Scientific Approach to Getting Healthier as You Get Older by Michael Greger. Copyright © 2023 by Michael Greger. Reprinted with permission from Flatiron Books. All rights reserved.

About the Author

Michael Greger, M.D. FACLM is a graduate of the Cornell University School of Agriculture and the Tufts University School of Medicine. He is a practicing physician and author of Bird Flu: A Virus of Our Own Hatching and Carbophobia: The Scary Truth Behind America’s Low Carb Craze. Three of his recent books—How Not to Die, the How Not to Die Cookbook, and How Not to Diet—became instant New York Times Best Sellers. Greger has lectured at the Conference on World Affairs and the National Institute of Health, testified before Congress, and appeared on shows such as The Colbert Report and Oprah Winfrey.

The abundance of wild birds, fish, amphibians, reptiles and insects has drastically declined over the past 50 years, but the scale and seriousness of this loss is often lost when we focus on the number of species in an area

Universe Today has explored the potential for sending humans to Europa, Venus, Titan, and Pluto, all of which possess environmental conditions that are far too harsh for humans to survive. The insight gained from planetary scientists resulted in some informative discussions, and traveling to some of these far-off worlds might be possible, someday. In the final installment of this series, we will explore the potential for sending humans to a destination that has been the focus of scientific exploration and science folklore for more than 100 years: Mars aka the Red Planet.

Dr. Jordan Bretzfelder, who is a Postdoctoral Fellow in the Department of Earth, Planetary, and Space Sciences at the University of California, Los Angeles (UCLA), shares her insights on the viability of sending humans to Mars and how we should do it. So, should we send humans to Mars?

“Yes, I think there is immense value in sending humans to engage in scientific exploration on Mars,” Dr. Bretzfelder tells Universe Today. “Humans can make quick decisions about sampling and data acquisition and can move around certain obstacles and terrain with more ease and freedom than many types of robotic vehicles. This would also provide opportunities to study and develop technology to facilitate future planetary exploration.”

Countless robotic pioneers have explored the surface and atmosphere of Mars in incredible detail and continue to teach us whether Mars once had—or currently has—life. However, humans could provide an extra level of exploration since they won’t be hindered by waiting for instructions from Earth ground controllers, which can take anywhere from 5 to 20 minutes one way. If something goes wrong, human explorers can make on-the-spot decisions to find solutions, whereas robot explorers are faced with waiting for engineers back on Earth to find solutions, followed by sending instructions, and more waiting. Regarding technological advancements, a human mission will undoubtedly teach us how to live and work on Mars, and this includes testing shelters, food, bathroom facilities, and even combating the mental fatigue from being so far from Earth for a prolonged period. All things considered, what are the pros and cons of sending humans to Mars?

Dr. Bretzfelder tells Universe Today, “Pros are as above, and many examples of the benefits of humans in the field can be found in the history of the Apollo missions; instances where certain scientifically valuable rocks were collected due to the quick thinking and judgement of the astronauts. Cons include the difficulties involved in keeping astronauts alive and safe on a distant and environmentally complicated planetary surface. Additionally, the possibility of accidentally introducing terrestrial microbes to Mars is a potential risk.”

Whether it’s a robotic or human mission, NASA’s Office of Planetary Protection is responsible for ensuring that microbes don’t hitch a ride and contaminate extraterrestrial environments that we wish to explore, but especially to protect us from any microbes that could potentially be brought back to Earth.

Regarding the ongoing robotic exploration of Mars, there are presently seven active Mars orbiters from several nations teaching us more and more about the Red Planet and unlocking its secrets. On the surface, there are currently three active missions: NASA’s Curiosity and Perseverance rovers, and China’s Zhurong rover. Past successful surface missions include NASA’s Viking 1 and Viking 2 landers, Mars Pathfinder, Spirit and Opportunity rovers, Phoenix lander, and InSight lander. From marsquakes to finding evidence for past surface liquid water, each of these missions spent years unlocking the secrets of Mars, both above and below the surface. But what additional science could be conducted by a human mission compared to a robotic mission?

“As above, humans (within limits based on their suits and other equipment) have the ability to navigate terrain that may not be suitable for a rover or helicopter,” Dr. Bretzfelder tells Universe Today. “They also can make real time decisions in the field about sampling etc., meaning there is less delay in waiting for signals from mission control to guide the rovers. Humans are also very adaptable to changing conditions and can respond quickly to address any issues or unexpected situations during a mission.”

In terms of an actual human habitat on Mars, countless images, videos, movies, and television shows have depicted a human habitat on the Martian surface, with very little depiction of a human habitat below the surface. While this depiction might be for aesthetics, a habitat on the surface would provide ideal surveying and sampling conditions, along with far better communications with Earth. However, a habitat on the surface would also expose the crew to dangerous amounts of solar radiation since Mars does not possess either an ozone layer or magnetic field like the Earth, both of which protect us from solar storms and other cosmic rays.

Artist’s concept for a crewed mission on Mars. (Credit: NASA/Clouds AO/SEArch)

In contrast, another type of human habitat could be below the surface, with past studies identifying the use of lava tubes for human settlements to shield them from the harmful solar radiation. However, any surface ventures could become tedious, along with communications with Earth becoming more complicated, even if a communications array was above-ground. Therefore, if humans were to travel to Mars, should it be above the surface or below?

Dr. Bretzfelder tells Universe Today, “An above surface mission, similar to the Apollo and upcoming Artemis missions would be the most feasible given the technology available and would limit impact to the Martian surface by simply operating above ground rather than excavating below ground. Samples or cores taken from depth may be scientifically valuable though.”

This discussion comes as NASA prepares to send humans back to the Moon as part of its Moon to Mars Architecture while SpaceX develops its Starship with the goal of sending humans to Mars, someday. China announced plans in 2021 to send their own astronauts to the Red Planet in 2033, with follow-up launches occurring every two years afterwards. Additionally, NASA has the goal of sending humans to Mars sometime in the 2030s.

“It is an exciting time to be able to seriously consider this type of exploration, and as we return to the Moon, we will likely learn valuable lessons to enable human exploration of Mars,” Dr. Bretzfelder tells Universe Today.

Will we ever send humans to Mars? Will such a mission achieve greater scientific objectives than the myriad of robotic missions sent to the Red Planet, and what could a human mission to Mars teach us about living and working so far from Earth? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Should We Send Humans to Mars? appeared first on Universe Today.

A recent study accepted to The Planetary Science Journal investigates how the organic hazes that existed on Earth between the planet’s initial formation and 500 million years afterwards, also known as Hadean geologic eon, could have contained the necessary building blocks for life, including nucleobases and amino acids. This study holds the potential to not only help scientists better understand the conditions on an early Earth, but also if these same conditions on Saturn’s largest moon, Titan, could produce the building blocks of life, as well.

Here, Universe Today discusses this recent study with Dr. Ben K. D. Pearce, who is a Postdoctoral Fellow in the Morton K. Blaustein Department of Earth & Planetary Sciences at Johns Hopkins University and lead author of the study, regarding the study’s findings, potential follow-up research, NASA’s upcoming Dragonfly mission to Titan, and whether he thinks there’s life on Titan.

Dr. Pearce tells Universe Today about how past lab studies involving Carl Sagan discovered that the highest dilution (or addition of a solvent like water) to make the chemical reactions work was 100 micromolar, or approximately 10 parts per million (ppm). If the dilution is too strong, the molecules in the chemical mixture wouldn’t find each other, he says.

“After all, early Earth was a hazy place, much akin to Saturn’s Moon Titan,” Dr. Pearce tells Universe Today. “This is because over 4 billion years ago, Earth had an atmosphere rich in hydrogen, methane, and nitrogen, similar to Titan! What’s interesting about these haze particles, is that they are essentially biomolecule snowflakes, i.e., big aggregates of life’s building blocks bonded together. When these particles settled onto Earth’s surface, over 4 billion years ago, and fell into ponds, the bonds would break, and you could get a pond rich in life’s building blocks. We wanted to know if this source could exceed the 100 micromolar threshold in ponds, which could be concentrated enough for them to react and begin the process of forming the first information molecules like ribonucleic acid (RNA).”

Artist’s impression of a hazy and ancient Earth. (Credit: NASA’s Goddard Space Flight Center/Francis Reddy)

For the study, the researchers created organic hazes in a laboratory setting under atmospheric conditions containing between 0.5 percent and 5 percent methane and analyzed the hazes for traces of amino acids and nucleobases using a gas chromatograph/mass spectrometer (GC/MS). Additionally, they heated samples up to 200 degrees Celsius (392 degrees Fahrenheit) to simulate the samples resting on an uninhabitable surface, as well. The team then compared their results to computer models to investigate the number of nucleobases that would be present in these same environments.

Artist’s illustration of a very violent early Earth. (Credit: NASA)

“When we modeled the pond concentrations of nucleobases from organic hazes (making use of our experimental data), we discovered that this source may be the richest, most long-lasting source that we’ve modeled to date,” Dr. Pearce tells Universe Today. “As a reminder, all sources we’ve studied to date (meteorites, interplanetary dust, and atmospheric HCN) have led to below 100 micromolar concentrations; however, now we have finally found a source that breaches up towards this threshold.”

In the end, the team discovered that nucleobases could exist in “warm little ponds” on Earth during the Hadean geologic eon. With the heating experiment, the team ascertained that such samples could not survive on a hot surface. Finally, they concluded that organic hazes could produce the building blocks of life only in a methane-rich atmosphere on ancient Earth, “but not so rich as to create an uninhabitable surface,” Dr. Pearce notes to Universe Today. Given these incredible findings, what follow-up research is being conducted or planned?

“I am presently building a new experimental setup to be used in my laboratory in the Department of Earth, Atmospheric, and Planetary Sciences at Purdue University, which opens this fall 2024,” Dr. Pearce tells Universe Today. “This lab is called the Origins and Astrobiology Research Laboratory. This experiment will allow my new research group to simultaneously model the atmospheric chemistry (e.g., HCN and organic haze production) and pond chemistry of early Earth. Our initial goal will be to use this to demonstrate the production of the first information molecules of life, such as RNA, in a simulated early Earth environment.”

This study comes as NASA is planning to send its Dragonfly mission to Titan, which currently has a planned launch date of July 2028 and landing on Titan’s surface sometime in 2034 in the “Shangri-La” dune fields. Dragonfly is a quadcopter whose goal will be to “hop” around Titan searching for evidence of Titan’s potential habitability, and currently has a planned mission timeline of 10 years with the science phase comprising 3.3 years. Its scientific payload will consist of a mass spectrometer, gamma-ray and neutron spectrometer, geophysics and meteorology package, and a suite of microscopic and panoramic cameras.

Dragonfly is slated to operate during the Titan day and remain on the ground at night, with each lasting approximately 8 Earth days or 192 hours. It is currently hypothesized that Dragonfly will be capable of flying up to 16 kilometers (10 miles) on a single battery charge, with its batteries consisting of a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) that will charge during the night. MMRTGs have a successful history on space missions, as they are currently used to power NASA’s Curiosity and Perseverance rovers on Mars. But how will Dragonfly contribute to or refute this study’s findings?

Artist’s impression of NASA’s Dragonfly quadcopter exploring the surface of Titan. (Credit: NASA)

Dr. Pearce tells Universe Today, “Given that there are tons of organic haze on Titan, we could expect that the surface contains preserved organic haze particles rich in life’s building blocks. Dragonfly will contain a mass spectrometer and will be able to characterize the building blocks of life in these particles to potentially validate our laboratory studies.”

Titan has a rich history of exploration, as numerous spacecraft over several decades have allowed us to gain greater insights into this mysterious world, which is not only the second-largest moon in the entire solar system but the only moon with a thick atmosphere. While the cameras onboard NASA’s Pioneer 11, Voyager 1, and Voyager 2 spacecraft were unable to image Titan’s surface due to the moon’s thick and hazy atmosphere, NASA’s Cassini spacecraft successfully used its infrared cameras to image Titan’s surface for the first time. It was these images that confirmed previous hypotheses that Titan possessed lakes of liquid methane and ethane that can only exist in extremely cold temperatures, with Titan’s surface temperature being minus 179 degrees Celsius (minus 290 degrees Fahrenheit).

Images of Titan obtained by NASA’s Cassini spacecraft on April 16, 2005: natural color composite (left), monochrome (center), and false-color composite (right). (Credit: NASA/JPL/Space Science Institute)

Cassini carried with it the European Space Agency’s Huygens probe, which detached from the orbiting spacecraft and landed on Titan’s surface, sending back surface features of rounded rocks that could have only formed under liquid conditions. But, given that Titan could resemble an early Earth with its methane atmosphere and liquid lakes, will we find life on Titan?

“The only habitable environment on Titan is deep in the subsurface, which is not easy to get to without a drill or a geyser spewing stuff onto the surface,” Dr. Pearce tells Universe Today. “Thus, I’m not sure we will even be looking in the best places for decades beyond Dragonfly. It is also hard for me to imagine an origin of life on Titan, given that our current best hypotheses involve wet-dry cycles of ponds that would not be available on -180 C Titan. However, if I have learned anything from science in the past decade, it’s that we are often proven wrong by new findings, and I absolutely welcome it! It’s always better to look, just in case!”

How will this recent study contribute to finding life on Titan, and what will Dragonfly teach us about Titan’s habitability in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post How Did Life Get Started on Earth? Atmospheric Haze Might Have Been the Key appeared first on Universe Today.

Engineers have demonstrated a system they've dubbed 'MadRadar' for fooling automotive radar sensors into believing almost anything is possible. The technology can hide the approach of an existing car, create a phantom car where none exists or even trick the radar into thinking a real car has quickly deviated from its actual course. And it can achieve this feat in the blink of an eye without having any prior knowledge about the specific settings of the victim's radar, making it the most troublesome threat to radar security to date.

Engineers have demonstrated a system they've dubbed 'MadRadar' for fooling automotive radar sensors into believing almost anything is possible. The technology can hide the approach of an existing car, create a phantom car where none exists or even trick the radar into thinking a real car has quickly deviated from its actual course. And it can achieve this feat in the blink of an eye without having any prior knowledge about the specific settings of the victim's radar, making it the most troublesome threat to radar security to date.

Researchers describe the discovery of a new method that transforms everyday materials like glass into materials scientists can use to make quantum computers.

Researchers describe the discovery of a new method that transforms everyday materials like glass into materials scientists can use to make quantum computers.

The earliest galaxies are thought to have formed as the gravitational pull of dark matter, which has been impossible to study directly, slowly drew in enough hydrogen and helium to ignite stars. But astrophysicists now show that after the Big Bang, hydrogen and helium gas bounced at supersonic speeds off dense, slowly moving clumps of cold dark matter. When the gas fell back in millennia later, stars formed all at once, creating small, exceptionally bright galaxies. If models of cold dark matter are correct, the James Webb Space Telescope should be able to find patches of bright galaxies in the early universe, potentially offering the first effective test for theories about dark matter. If it doesn't, scientists have to go back to the drawing board with dark matter.

The field of exoplanet study continues to grow by leaps and bounds. As of the penning of this article, 5,572 extrasolar planets have been confirmed in 4,150 systems (with another 10,065 candidates awaiting confirmation. Well, buckle up because six more exoplanets have been confirmed around TOI-1136, a Sun-like star located roughly 276 light-years from Earth. This star is less than 700 million years old, making it relatively young compared to our own (4.6 billion years). This system will allow astronomers to observe how systems like our own have evolved with time.

The six-planet system was confirmed by the TESS Keck Survey, an international team of astronomers that searches for exoplanets by combing data obtained by the Transiting Exoplanet Survey Satellite (TESS) and the W.M. Keck Observatory (of which UC Riverside planetary astrophysics professor Stephen Kane is the principal investigator). The details of the six-planet system were presented in a series of papers that appeared in The Astronomical Journal. In the seventeenth and latest paper in the series, the survey team presented precise mass measurements of the six exoplanets, details about their orbits, and the characteristics of their atmospheres.

To date, most of the exoplanets observed by astronomers have been either individual discoveries or one of just a few planets. But in some cases, such as Kepler-90 and TRAPPIST-1, astronomers have observed many planets in a single system (8 and 7, respectively). Depending on the age of their parent star, these systems present astronomers with the opportunity to observe how multi-planet systems formed and evolved. In the case of TOI-1136, its age sets it apart from many known systems, being merely 700 million years old.

Artist’s impression of the planetary system around Kepler-90, a Sun-like star 2,545 light years from Earth. Credits: NASA

Tara Fetherolf, a visiting assistant professor of astrophysics at Cal State San Marcos and co-author of a new paper, explained in a UC Riverside News release:

“Because few star systems have as many planets as this one does, it’s getting close in size to our own Solar System. It’s both similar enough and different enough that we can learn a lot. This gives us a look at planets right after they’ve formed, and solar system formation is a hot topic. Any time we find a multi-planet system it gives us more information to inform our theories about how systems come to be and how our system.”

Initial observations of the system were made in 2019 using TESS, which was followed up with observations using the High-Resolution Echelle Spectrometer (HIRES) at the W.M. Keck Observatory and the Automated Planet Finder (APF) at the Lick Observatory. The latter observations allowed the team to precisely constrain the mass of the planets using the Radial Velocity measurements (where slight variations in the star’s motion indicate the gravitational forces acting on it). This yielded estimates of about 3.5 (TOI-1135 b) to 9.7 (TOI-1135 f) Earth masses, placing them between Super Earths to Mini-Neptunes.

The team also used Transit Timing variations, where dips in a star’s luminosity are used to determine the presence of planets (and their size). They then created computer models where the velocity measurements were layered over the transit data, yielding more information about the system. Typically, young stars are difficult to study because they are so active, possessing powerful magnetic fields, sunspots, and powerful solar flares that influence their planets by affecting their atmospheres. Since all the planets observed around TOI-1136 are of a similar age, they likely formed under similar conditions.

An amusing rendition of the TOI-1136 system if each body in the system were a duck or duckling. Credit: Rae Holcomb/UCI

And since the planets of this system are relatively close to each other, the team was able to measure something hard to gauge in other systems. As Kane summarized:

“Young stars misbehave all the time. They’re very active, just like toddlers. That can make high-precision measurements difficult. This will help us not only do a one-to-one comparison of how planets change with time but also how their atmospheres evolved at different distances from the star, which is perhaps the most key thing.”

The results of this study could have far-reaching implications for exoplanet research and the search for life in the cosmos (astrobiology). According to the most recent fossilized evidence, life emerged on Earth during the Archaean Eon (ca. 3.9 billion years ago), almost immediately after it formed. While many of TOI-1136’s planets orbit too closely and are subject to too much radiation to make life likely, the team hopes that observations of this system will ultimately answer questions of how our planet and life as we know it came to be.

“Are we rare?” said Kane. “I’m increasingly convinced our system is highly unusual in the Universe. Finding systems so unlike our own makes it increasingly clear how our Solar System fits into the broader context of formation around other stars.”

Further Reading: UC Riverside, The Astronomical Journal

The post Six Planets Found Orbiting an Extremely Young Star appeared first on Universe Today.

Executives from Meta, TikTok and X were questioned by US lawmakers about the safety of children who use their products – experts say the companies need to do more than just provide parental controls

Nine out of ten people in a trial of a CRISPR treatment for potentially life-threatening inflammatory reactions seem to have been cured

When a prominent star in the night sky suddenly dims, it generates a lot of interest. That’s what happened with the red supergiant star Betelgeuse between November 2019 and May 2020. Betelgeuse will eventually explode as a supernova. Was the dimming a signal that the explosion was imminent?

No, and new research helps explain why.

Headline writers couldn’t resist the supernova angle, even though that explanation was never very likely. Eventually, it became clear that ejected dust from the star caused the dimming. New research based on observations before, during, and after the Great Dimming Event (GDE) supports the idea that dust from the star itself caused Betelgeuse’s drop in brightness.

A research letter titled “Images of Betelgeuse with VLTI/MATISSE across the Great Dimming” presents the infrared observations of Betelgeuse. The observations capture the star before, during, and after the GDE. The lead author is Julien Drevon, from the Université Côte d’Azur, France, and the European Southern University.

“To better understand the dimming event, we used mid-infrared long-baseline spectro-interferometric measurements of Betelgeuse taken with the VLTI/MATISSE instrument before (Dec. 2018), during (Feb. 2020) and after (Dec. 2020) the GDE,” the research letter states. In particular, their observations focus on silicon monoxide (SiO.)

The authors of the new research outline three steps in the process that created the GDE.

Step One

The GDE started with shocks deep inside Betelgeuse. They generated a convective outflow of plasma that brought material to the star’s surface. Researchers detected a strong shock in February 2018 and a weaker one in January 2019. The second, weaker shock boosted the effect of the stronger shock that preceded it, generating a progressive plasma flow at the surface of Betelgeuse’s photosphere.

Step Two

The plasma flowing to the photosphere’s surface created a hot spot. Hubble UV observations of Betelgeuse revealed the presence of a luminous, hot, dense structure in the star’s southern hemisphere, between the photosphere and the chromosphere.

Step Three

Stellar material detaches from the photosphere and forms a gas cloud above Betelgeuse’s surface. A colder region forms under this cloud as a dark spot. Since it’s cooler, dust is allowed to condense above this region and in the part of the cloud above it. That dust is what blocked some of Betelgeuse’s luminosity, causing the GDE.

Previous research revealed this three-step process behind the GDE. The authors of the new research article set out to observe Betelgeuse’s close circumstellar environment to probe and monitor its geometry. In the wavelength range they worked in, SiO spectral features are prominent, and they’re used to understand what happened with the red supergiant. In astronomy, SiO is used as a tracer for shocked gas in stellar outflows since it persists at high temperatures.

This figure from the research letter shows some of the data the researchers worked with. The top panel shows the absolute spectra during each observed epoch. The bottom panel shows the relative flux for the SiO bands. The bands are deeper during the GDE than either before or after. Image Credit: J. Drevon et al. 2024.

In their article, the authors focus on the SiO (2-0) band and what it signifies. They note how the band’s intensity contrast increases by 14% during the GDE. “Therefore, it seems that during the GDE, we observe brighter structures in the line of sight,” they explain.

Next, they note a 50% decrease in intensity contrast in December 2020. What does it mean?

“The SiO (2–0) opacity depth map shows, therefore, strong temporal variations within 2 years, indicative of vigorous changes in the star’s environment in this time span,” they write.

Their observations also suggest “the presence of an infrared excess in the pseudo continuum during the GDE, which has been interpreted as new hot dust formed,” Drevon and his colleagues write.

This figure from the research article explains some of what the researchers found. The middle column is particularly interesting because it’s a reconstruction of the SiO (2-0) absorption band onto Betelgeuse’s surface for each of the three observed epochs. The third column is similar but shows the SiO (2-0) optical depth. Overall, they constrain the geometry of the dust feature that caused the GDE. Image Credit: J. Drevon et al. 2024.

It seems like the Great Dimming is no longer the mystery it once was. It also shows that Occam’s Razor is alive and well: “The explanation that requires the fewest assumptions is usually correct.”

The supernova proposal was fun for a while, and one day, Betelgeuse will explode as a supernova. But before it ever does, there are likely going to be several more episodes of dimming. For now, the authors say that the star is returning to normal.

“The Dec. 2020 observations suggest that Betelgeuse seems to be returning to a gas and surface environment similar to the one observed in Dec. 2018,” they write, “but with smoother structures, maybe
due to the unusual amount of dust recently formed during the GDE in the line of sight.”

Case closed?

The post Betelgeuse. Before, During and After the Great Dimming appeared first on Universe Today.

Although solar flares have been classified based on the amount of energy they emit at their peak, there has not been significant study into differentiating flares since slow-building flares were first discovered in the 1980s. Scientists have now shown that there is a significant amount of slower-type flares worthy of further investigation.

A new paper describes how, despite widespread enthusiasm about artificial intelligence's potential to revolutionize healthcare and the use of AI-powered tools on millions of patients already, no federal regulations require that AI-powered tools be evaluated for potential harm or benefit to patients.

A new system that brings together real-world sensing and virtual reality would make it easier for building maintenance personnel to identify and fix issues in commercial buildings that are in operation.

A new system that brings together real-world sensing and virtual reality would make it easier for building maintenance personnel to identify and fix issues in commercial buildings that are in operation.

Researchers have successfully developed a new time-resolved atomic force microscopy (AFM) technique, integrating AFM with a unique laser technology. This method enables the measurement of ultrafast photoexcitation phenomena in both conductors and insulators, observed through changes in the forces between the sample and the AFM probe tip after an extremely short time irradiation of laser light. This advancement promises substantial contributions to the creation of new scientific and technological principles and fields.