Lots of Tatooine-like planets around binary stars may be habitable

Lots of Tatooine-like planets around binary stars may be habitable

Planets with twin suns, such as this hypothetical world in the Kepler-35 system (shown in an artist’s impression), may make up the bulk of habitable worlds in the universe.

JPL-Caltech/NASA

SEATTLE — Luke Skywalker’s home planet in Star Wars is the stuff of science fiction. But Tatooine-like planets in orbit around pairs of stars might be our best bet in the search for habitable planets beyond our solar system.

Many stars in the universe come in pairs. And lots of those should have planets orbiting them ( SN: 10/25/21 ). That means there could be many more planets orbiting around binaries than around solitary stars like ours. But until now, no one had a clear idea about whether those planets’ environments could be conducive to life. New computer simulations suggest that, in many cases, life could imitate art.

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Earthlike planets orbiting some configurations of binary stars can stay in stable orbits for at least a billion years , researchers reported January 11 at the American Astronomical Society meeting. That sort of stability, the researchers propose, would be enough to potentially allow life to develop, provided the planets aren’t too hot or cold.

Of the planets that stuck around, about 15 percent stayed in their habitable zone — a temperate region around their stars where water could stay liquid — most or even all of the time.

The researchers ran simulations of 4,000 configurations of binary stars, each with an Earthlike planet in orbit around them. The team varied things like the relative masses of the stars, the sizes and shapes of the stars’ orbits around each other, and the size of the planet’s orbit around the binary pair.

The scientists then tracked the motion of the planets for up to a billion years of simulated time to see if the planets would stay in orbit over the sorts of timescales that might allow life to emerge.

A planet orbiting binary stars can get kicked out of the star system due to complicated interactions between the planet and stars. In the new study, the researchers found that, for planets with large orbits around star pairs, only about 1 out of 8 were kicked out of the system. The rest were stable enough to continue to orbit for the full billion years. About 1 in 10 settled in their habitable zones and stayed there.

Of the 4,000 planets that the team simulated, roughly 500 maintained stable orbits that kept them in their habitable zones at least 80 percent of the time.

“The habitable zone . . . as I’ve characterized it so far, spans from freezing to boiling,” said Michael Pedowitz, an undergraduate student at the College of New Jersey in Ewing who presented the research. Their definition is overly strict, he said, because they chose to model Earthlike planets without atmospheres or oceans. That’s simpler to simulate, but it also allows temperatures to fluctuate wildly on a planet as it orbits.

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“An atmosphere and oceans would smooth over temperature variations fairly well,” says study coauthor Mariah MacDonald, an astrobiologist also at the College of New Jersey. An abundance of air and water would potentially allow a planet to maintain habitable conditions, even if it spent more of its time outside of the nominal habitable zone around a binary star system.

The number of potentially habitable planets “will increase once we add atmospheres,” MacDonald says, “but I can’t yet say by how much.”

She and Pedowitz hope to build more sophisticated models in the coming months, as well as extend their simulations beyond a billion years and include changes in the stars that can affect conditions in a solar system as it ages.

The possibility of stable and habitable planets in binary star systems is a timely issue says Penn State astrophysicist Jason Wright, who was not involved in the study.

“At the time Star Wars came out,” he says, “we didn’t know of any planets outside the solar system, and wouldn’t for 15 years. Now we know that there are many and that they orbit these binary stars.”

These simulations of planets orbiting binaries could serve as a guide for future experiments, Wright says. “This is an under-explored population of planets. There’s no reason we can’t go after them, and studies like this are presumably showing us that it’s worthwhile to try.”

M. Pedowitz and M. MacDonald. Constraining the long-term stability and habitability of circumbinary planets . American Astronomical Society meeting, Seattle, January 11, 2023.

James Riordon is a freelance science writer who covers physics, math, astronomy and occasional lifestyle stories.

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Lots of Tatooine-like planets around binary stars may be habitable

Procrastination may harm your health. Here’s what you can do

Procrastination may harm your health. Here’s what you can do

Scientists estimate that some 20 percent of adults are chronic procrastinators. A little self-compassion might help.

Henrik Sorensen/DigitalVision/Getty Images

The worst procrastinators probably won’t be able to read this story. It’ll remind them of what they’re trying to avoid, psychologist Piers Steel says.

Maybe they’re dragging their feet going to the gym. Maybe they haven’t gotten around to their New Year’s resolutions. Maybe they’re waiting just one more day to study for that test.

Procrastination is “putting off to later what you know you should be doing now,” even if you’ll be worse off, says Steel, of the University of Calgary in Canada. But all those tasks pushed to tomorrow seem to wedge themselves into the mind — and it may be harming people’s health.

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In a study of thousands of university students, scientists linked procrastination to a panoply of poor outcomes , including depression, anxiety and even disabling arm pain. “I was surprised when I saw that one,” says Fred Johansson, a clinical psychologist at Sophiahemmet University in Stockholm. His team reported the results January 4 in JAMA Network Open .

The study is one of the largest yet to tackle procrastination’s ties to health. Its results echo findings from earlier studies that have gone largely ignored, says Fuschia Sirois, a behavioral scientist at Durham University in England, who was not involved with the new research.

For years, scientists didn’t seem to view procrastination as something serious, she says. The new study could change that. “It’s that kind of big splash that’s … going to get attention,” Sirois says. “I’m hoping that it will raise awareness of the physical health consequences of procrastination.”

Whether procrastination harms health can seem like a chicken-and-egg situation.

It can be hard to tell if certain health problems make people more likely to procrastinate — or the other way around, Johansson says. (It may be a bit of both.) And controlled experiments on procrastination aren’t easy to do: You can’t just tell a study participant to become a procrastinator and wait and see if their health changes, he says.

In a new study, researchers have tied procrastination to a range of potential health issues and other negative outcomes, including:

Many previous studies have relied on self-reported surveys taken at a single time point. But a snapshot of someone makes it tricky to untangle cause and effect. Instead, in the new study, about 3,500 students were followed over nine months, so researchers could track whether procrastinating students later developed health issues.

On average, these students tended to fare worse over time than their prompter peers. They were slightly more stressed, anxious, depressed and sleep-deprived, among other issues, Johansson and colleagues found. “People who score higher on procrastination to begin with … are at greater risk of developing both physical and psychological problems later on,” says study coauthor Alexander Rozental, a clinical psychologist at Uppsala University in Sweden. “There is a relationship between procrastination at one time point and having these negative outcomes at the later point.”

The study was observational, so the team can’t say for sure that procrastination causes poor health. But results from other researchers also seem to point in this direction. A 2021 study tied procrastinating at bedtime to depression . And a 2015 study from Sirois’ lab linked procrastinating to poor heart health .

Stress may be to blame for procrastination’s ill effects, data from Sirois’ lab and other studies suggest. She thinks that the effects of chronic procrastinating could build up over time. And though procrastination alone may not cause disease, Sirois says, it could be “one extra factor that can tip the scales.”

Some 20 percent of adults are estimated to be chronic procrastinators. Everyone might put off a task or two, but chronic procrastinators make it their lifestyle, says Joseph Ferrari, a psychologist at DePaul University in Chicago, who has been studying procrastination for decades. “They do it at home, at school, at work and in their relationships.” These are the people, he says, who “you know are going to RSVP late.”

Though procrastinators may think they perform better under pressure, Ferrari has reported the opposite. They actually worked more slowly and made more errors than non-procrastinators, his experiments have shown. And when deadlines are slippery, procrastinators tend to let their work slide , Steel’s team reported last year in Frontiers in Psychology

For years, researchers have focused on the personalities of people who procrastinate. Findings vary, but some scientists suggest procrastinators may be impulsive, worriers and have trouble regulating their emotions. One thing procrastinators are not, Ferrari emphasizes, is lazy. They’re actually “very busy doing other things than what they’re supposed to be doing,” he says.

In fact, Rozental adds, most research today suggests procrastination is a behavioral pattern.

And if procrastination is a behavior, he says, that means it’s something you can change, regardless of whether you’re impulsive.

When people put off a tough task, they feel good — in the moment.

“You made a mistake and procrastinated. It’s not the end of the world…. What can you do to move forward?

Procrastinating is a way to sidestep the negative emotions linked to the task, Sirois says. “We’re sort of hardwired to avoid anything painful or difficult,” she says. “When you procrastinate, you get immediate relief.” A backdrop of stressful circumstances — say, a worldwide pandemic — can strain people’s ability to cope, making procrastinating even easier. But the relief it provides is only temporary, and many seek out ways to stop dawdling.

Researchers have experimented with procrastination treatments that run the gamut from the logistical to the psychological. What works best is still under investigation. Some scientists have reported success with time-management interventions. But the evidence for that “is all over the map,” Sirois says. That’s because “poor time management is a symptom not a cause of procrastination,” she adds.

For some procrastinators, seemingly obvious tips can work. In his clinical practice, Rozental advises students to simply put down their smartphones. Silencing notifications or studying in the library rather than at home can quash distractions and keep people on task. But that won’t be enough for many people, he says.

Hard-core procrastinators may benefit from cognitive behavioral therapy. In a 2018 review of procrastination treatments , Rozental found that this type of therapy, which involves managing thoughts and emotions and trying to change behavior, seemed to be the most helpful. Still, not many studies have examined treatments, and there’s room for improvement, he says.

Sirois also favors an emotion-centered approach. Procrastinators can fall into a shame spiral where they feel uneasy about a task, put the task off, feel ashamed for putting it off and then feel even worse than when they started. People need to short-circuit that loop, she says. Self-forgiveness may help , scientists suggested in one 2020 study. So could mindfulness training.

In a small trial of university students, eight weekly mindfulness sessions reduced procrastination , Sirois and colleagues reported in the January Learning and Individual Differences . Students practiced focusing on the body, meditating during unpleasant activities and discussed the best way to take care of themselves. A little self-compassion may snap people out of their spiral, Sirois says.

“You made a mistake and procrastinated. It’s not the end of the world,” she says. “What can you do to move forward?”

F. Johansson et al . Associations between procrastination and subsequent health outcomes among university students in Sweden. JAMA Network Open . Published online January 4, 2023. doi: 10.1001/jamanetworkopen.2022.49346.

H.S. Rad et al . Mindfulness intervention for academic procrastination: A randomized control trial. Learning and Individual Differences . Vol. 101, January 2023. doi: 10.1016/j.lindif.2022.102244.

P. Steel et al. Self-regulation of slippery deadlines: The role of procrastination in work performance. Frontiers in Psychology . Vol. 12, January 6, 2022, p. 783789. doi: 10.3389/fpsyg.2021.783789.

G. Cui et al. Longitudinal relationships among problematic mobile phone use, bedtime procrastination, sleep quality and depressive symptoms in Chinese college students: a cross-lagged panel analysis. BMC Psychiatry . Vol. 21, September 10, 2021, p. 449. doi: 10.1186/s12888-021-03451-4.

L. Martinčeková and R.D. Enright.  The effects of self-forgiveness and shame-proneness on procrastination: exploring the mediating role of affect . Current Psychology . Vol. 39, April 2020, p. 428. doi: 10.1007/s12144-018-9926-3.

A. Rozental et al . Targeting procrastination using psychological treatments: A systematic review and meta-analysis . Frontiers in Psychology . Vol. 9, August 30, 2018, p. 1588. doi: 10.3389/fpsyg.2018.01588.

F.M. Sirois. Is procrastination a vulnerability factor for hypertension and cardiovascular disease? Testing an extension of the procrastination–health model . Journal of Behavioral Medicine . Vol. 38, June 2015, p. 578. doi: 10.1007/s10865-015-9629-2.

J.R. Ferrari. Procrastination as self-regulation failure of performance: effects of cognitive load, self-awareness, and time limits on ‘working best under pressure.’ European Journal of Personality . Vol. 15, September/October 2001, p. 391. doi: 10.1002/per.413.

Meghan Rosen is a staff writer who reports on the life sciences for Science News . She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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Procrastination may harm your health. Here’s what you can do

These shape-shifting devices melt and re-form thanks to magnetic fields

These shape-shifting devices melt and re-form thanks to magnetic fields

This Lego-like figurine escaped from prison Terminator 2 –style thanks to a new composite of gallium and magnetic particles, which liquefies in the presence of a changing magnetic field and moves under the guidance of a permanent magnet.

Q. Wang  et al / Matter  2023 (CC BY-SA)

Shape-shifting liquid metal robots might not be limited to science fiction anymore.

Miniature machines can switch from solid to liquid and back again to squeeze into tight spaces and perform tasks like soldering a circuit board, researchers report January 25 in Matter .

This phase-shifting property, which can be controlled remotely with a magnetic field, is thanks to the metal gallium. Researchers embedded the metal with magnetic particles to direct the metal’s movements with magnets . This new material could help scientists develop soft, flexible robots that can shimmy through narrow passages and be guided externally.  

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Scientists have been developing magnetically controlled soft robots for years. Most existing materials for these bots are made of either stretchy but solid materials, which can’t pass through the narrowest of spaces, or magnetic liquids , which are fluid but unable to carry heavy objects ( SN: 7/18/19 ).

In the new study, researchers blended both approaches after finding inspiration from nature ( SN: 3/3/21 ). Sea cucumbers, for instance, “can very rapidly and reversibly change their stiffness,” says mechanical engineer Carmel Majidi of Carnegie Mellon University in Pittsburgh. “The challenge for us as engineers is to mimic that in the soft materials systems.”

So the team turned to gallium, a metal that melts at about 30° Celsius — slightly above room temperature. Rather than connecting a heater to a chunk of the metal to change its state, the researchers expose it to a rapidly changing magnetic field to liquefy it. The alternating magnetic field generates electricity within the gallium, causing it to heat up and melt. The material resolidifies when left to cool to room temperature.

Since magnetic particles are sprinkled throughout the gallium, a permanent magnet can drag it around. In solid form, a magnet can move the material at a speed of about 1.5 meters per second. The upgraded gallium can also carry about 10,000 times its weight.

External magnets can still manipulate the liquid form, making it stretch, split and merge. But controlling the fluid’s movement is more challenging, because the particles in the gallium can freely rotate and have unaligned magnetic poles as a result of melting. Because of their various orientations, the particles move in different directions in response to a magnet.

Majidi and colleagues tested their strategy in tiny machines that performed different tasks. In a demonstration straight out of the movie Terminator 2 , a toy person escaped a jail cell by melting through the bars and resolidifying in its original form using a mold placed just outside the bars.

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On the more practical side, one machine removed a small ball from a model human stomach by melting slightly to wrap itself around the foreign object before exiting the organ. But gallium on its own would turn to goo inside a real human body, since the metal is a liquid at body temperature, about 37° C. A few more metals, such as bismuth and tin, would be added to the gallium in biomedical applications to raise the material’s melting point, the authors say. In another demonstration, the material liquefied and rehardened to solder a circuit board.

Although this phase-shifting material is a big step in the field, questions remain about its biomedical applications, says biomedical engineer Amir Jafari of the University of North Texas in Denton, who was not involved in the work. One big challenge, he says, is precisely controlling magnetic forces inside the human body that are generated from an external device.

“It’s a compelling tool,” says robotics engineer Nicholas Bira of Harvard University, who was also not involved in the study. But, he adds, scientists who study soft robotics are constantly creating new materials.

“The true innovation to come lies in combining these different innovative materials.”

Q. Wang et al . Magnetoactive liquid-solid phase transitional matter . Matter. Published online January 25, 2023. doi: 10.1016/j.matt.2022.12.003

McKenzie Prillaman is the Spring 2023 science writing intern at  Science News . She holds a bachelor’s degree in neuroscience with a minor in bioethics from the University of Virginia and a master’s degree in science communication from the University of California, Santa Cruz.

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These shape-shifting devices melt and re-form thanks to magnetic fields

These chemists cracked the code to long-lasting Roman concrete

These chemists cracked the code to long-lasting Roman concrete

Built from concrete around 126 A.D., the Pantheon in Rome still stands, including its soaring dome (shown).

Stephen Knowles Photography/Moment/Getty Images Plus

MIT chemist Admir Masic really hoped his experiment wouldn’t explode.

Masic and his colleagues were trying to re-create an ancient Roman technique for making concrete, a mix of cement, gravel, sand and water. The researchers suspected that the key was a process called “hot mixing,” in which dry granules of calcium oxide, also called quicklime, are mixed with volcanic ash to make the cement. Then water is added.

Hot mixing, they thought, would ultimately produce a cement that wasn’t completely smooth and mixed, but instead contained small calcium-rich rocks. Those little rocks, ubiquitous in the walls of the Romans’ concrete buildings, might be the key to why those structures have withstood the ravages of time.

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That’s not how modern cement is made. The reaction of quicklime with water is highly exothermic, meaning that it can produce a lot of heat — and possibly an explosion.

“Everyone would say, ‘You are crazy,’” Masic says.

But no big bang happened. Instead, the reaction produced only heat, a damp sigh of water vapor — and a Romans-like cement mixture bearing small white calcium-rich rocks.

Researchers have been trying for decades to re-create the Roman recipe for concrete longevity — but with little success. The idea that hot mixing was the key was an educated guess.

Masic and colleagues had pored over texts by Roman architect Vitruvius and historian Pliny, which offered some clues as to how to proceed. These texts cited, for example, strict specifications for the raw materials, such as that the limestone that is the source of the quicklime must be very pure, and that mixing quicklime with hot ash and then adding water could produce a lot of heat.

The rocks were not mentioned, but the team had a feeling they were important.

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“In every sample we have seen of ancient Roman concrete, you can find these white inclusions,” bits of rock embedded in the walls. For many years, Masic says, the origin of those inclusions was unclear — researchers suspected incomplete mixing of the cement, perhaps. But these are the highly organized Romans we’re talking about. How likely is it that “every operator [was] not mixing properly and every single [building] has a flaw?”

What if, the team suggested, these inclusions in the cement were actually a feature, not a bug? The researchers’ chemical analyses of such rocks embedded in the walls at the archaeological site of Privernum in Italy indicated that the inclusions were very calcium-rich.

That suggested the tantalizing possibility that these rocks might be helping the buildings heal themselves from cracks due to weathering or even an earthquake. A ready supply of calcium was already on hand: It would dissolve, seep into the cracks and re-crystallize. Voila! Scar healed.

But could the team observe this in action? Step one was to re-create the rocks via hot mixing and hope nothing exploded. Step two: Test the Roman-inspired cement. The team created concrete with and without the hot mixing process and tested them side by side. Each block of concrete was broken in half, the pieces placed a small distance apart. Then water was trickled through the crack to see how long it took before the seepage stopped.

“The results were stunning,” Masic says. The blocks incorporating hot mixed cement healed within two to three weeks. The concrete produced without hot mixed cement never healed at all , the team reports January 6 in Science Advances .

Cracking the recipe could be a boon to the planet. The Pantheon and its soaring, detailed concrete dome have stood nearly 2,000 years , for instance, while modern concrete structures have a lifespan of perhaps 150 years, and that’s a best case scenario ( SN: 2/10/12 ). And the Romans didn’t have steel reinforcement bars shoring up their structures.

More frequent replacements of concrete structures means more greenhouse gas emissions. Concrete manufacturing is a huge source of carbon dioxide to the atmosphere, so longer-lasting versions could reduce that carbon footprint. “We make 4 gigatons per year of this material,” Masic says. That manufacture produces as much as 1 metric ton of CO 2 per metric ton of produced concrete, currently amounting to about 8 percent of annual global CO 2 emissions.

Still, Masic says, the concrete industry is resistant to change. For one thing, there are concerns about introducing new chemistry into a tried-and-true mixture with well-known mechanical properties. But “the key bottleneck in the industry is the cost,” he says. Concrete is cheap, and companies don’t want to price themselves out of competition.

The researchers hope that reintroducing this technique that has stood the test of time, and that could involve little added cost to manufacture, could answer both these concerns. In fact, they’re banking on it: Masic and several of his colleagues have created a startup they call DMAT that is currently seeking seed money to begin to commercially produce the Roman-inspired hot-mixed concrete. “It’s very appealing simply because it’s a thousands-of-years-old material.”

L.M. Seymour et al . Hot mixing: Mechanistic insights into the durability of ancient Roman concretes . Science Advances . Published online January 6, 2023. doi: 10.1126/sciadv.add1602

Carolyn Gramling is the earth & climate writer. She has bachelor’s degrees in geology and European history and a Ph.D. in marine geochemistry from MIT and the Woods Hole Oceanographic Institution.

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These chemists cracked the code to long-lasting Roman concrete

These adorable Australian spike-balls beat the heat with snot bubbles

These adorable Australian spike-balls beat the heat with snot bubbles

Echidnas, spiky egg-laying mammals that live across Australia, blow snot bubbles to keep cool, a new study finds.

Nuytsia@Tas/Flickr ( CC BY-NC-SA 2.0 )

Animals cover themselves in all kinds of unsavory fluids to keep cool. Humans sweat, kangaroos spit and some birds will urinate on themselves to survive hot days. It turns out that echidnas do something much cuter — though perhaps just as sticky (and slightly icky) — to beat the heat.

The spiny insectivores stay cool by blowing snot bubbles , researchers report January 18 in Biology Letters . The bubbles pop, keeping the critters’ noses moist. As it evaporates, this moisture draws heat away from a blood-filled sinus in the echidna’s beak, helping to cool the animal’s blood.

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Short-beaked echidnas ( Tachyglossus aculeatus ) look a bit like hedgehogs but are really monotremes — egg-laying mammals unique to Australia and New Guinea ( SN: 11/18/16 ). Previous lab studies showed that temperatures above 35° Celsius (95° Fahrenheit) should kill echidnas. But echidnas don’t seem to have gotten the memo. They live everywhere from tropical rainforests to deserts to snow-capped peaks, leaving scientists with a physiological puzzle.

Mammals evaporate water to keep cool when temperatures climb above their body temperatures, says environmental physiologist Christine Cooper of Curtin University in Perth, Australia. “Lots of mammals do that by either licking, sweating or panting,” she says. “Echidnas weren’t believed to be able to do that.” But it’s known that the critters blow snot bubbles when it gets hot.

So, armed with a heat-vision camera and a telephoto lens, Cooper and environmental physiologist Philip Withers of the University of Western Australia in Perth drove through nature reserves in Western Australia once a month for a year to film echidnas.

In infrared, the warmest parts of the echidnas’ spiny bodies glowed in oranges, yellows and whites. But the video revealed that the tips of their noses were dark purple blobs, kept cool as moisture from their snot bubbles evaporated. Echidnas might also lose heat through their bellies and legs, the researchers report, while their spikes could act as an insulator.

“Finding a way of doing this work in the field is pretty exciting,” says physiological ecologist Stewart Nicol of the University of Tasmania in Hobart, Australia, who was not involved in the study. “You can understand animals and see how they’re responding to their normal environment.” The next step, he says, is to quantify how much heat echidnas really lose through their noses and other body parts.

Monotremes parted evolutionary ways with other mammals between 250 million and 160 million years ago as the supercontinent Pangaea broke apart ( SN: 3/8/15 ). So “they have a whole lot of traits that are considered to be primitive,” Cooper says. “Understanding how they might thermoregulate can give us some ideas about how thermal regulation … might have evolved in mammals.”

C.E. Cooper and P.C. Withers. Postural, pilo-erective and evaporative thermal windows of the short-beaked echidna ( Tachyglossus aculeatus ) . Biology Letters . Published online January 18, 2023. doi: 10.1098/rsbl.2022.0495.

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These adorable Australian spike-balls beat the heat with snot bubbles

These microbes are the first known to be able to eat only viruses

These microbes are the first known to be able to eat only viruses

Halteria ciliates (three shown) each ate around 10,000 to 1 million viruses daily in laboratory experiments. In the wild, that number could skyrocket to up to around 1 quadrillion, scientists estimate.

Scenics & Science/Alamy Stock Photo

New Year, new viral diet — literally.

Tiny, pond-dwelling Halteria ciliates are virovores , able to survive on a virus-only diet, researchers report December 27 in Proceedings of the National Academy of Sciences . The single-celled creatures are the first known to thrive when viruses alone are on the menu.

Scientists already knew that some microscopic organisms snack on aquatic viruses such as chloroviruses, which infect and kill algae. But it was unclear whether viruses alone could provide enough nutrients for an organism to grow and reproduce, says ecologist John DeLong of the University of Nebraska–Lincoln.

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In laboratory experiments, Halteria that were living in water droplets and given only chloroviruses for sustenance reproduced, DeLong and colleagues found. As the number of viruses in the water dwindled, Halteria numbers went up. Ciliates without access to viral morsels, or any other food, didn’t multiply. But Paramecium , a larger microbe, didn’t thrive on a virus-only diet, hinting that viruses can’t satisfy the nutritional requirements for all ciliates to grow. 

Viruses could be a good source of phosphorus, which is essential for making copies of genetic material, DeLong says. But it probably takes a lot of viruses to account for a full meal.

In the lab, each Halteria microbe ate about 10,000 to 1 million viruses daily, the team estimates. Halteria in small ponds with abundant viral snacks might chow down on about a quadrillion viruses per day.

These feasts could shunt previously unrecognized energy into the food web, and add a new layer to the way viruses move carbon through an ecosystem — if it happens in the wild, DeLong says ( SN: 6/9/16 ). His team plans to start finding out once ponds in Nebraska thaw.  

J.P. DeLong et al . The consumption of viruses returns energy to food chains . Proceedings of the National Academy of Sciences . Published online December 27, 2022. doi: 10.1073/pnas.2215000120.

Erin I. Garcia de Jesus is a staff writer at Science News . She holds a Ph.D. in microbiology from the University of Washington and a master’s in science communication from the University of California, Santa Cruz.

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These microbes are the first known to be able to eat only viruses