Science
‘Zombie’ virus spent 48,500 years in permafrost: scientists
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Warmer temperatures in the Arctic are thawing the region’s permafrost — a frozen layer of soil beneath the ground — and potentially stirring viruses that, after lying dormant for tens of thousands of years, could endanger animal and human health.
While a pandemic unleashed by a disease from the distant past sounds like the plot of a sci-fi movie, scientists warn that the risks, though low, are underappreciated. Chemical and radioactive waste that dates back to the Cold War, which has the potential to harm wildlife and disrupt ecosystems, may also be released during thaws.
“There’s a lot going on with the permafrost that is of concern, and (it) really shows why it’s super important that we keep as much of the permafrost frozen as possible,” said Kimberley Miner, a climate scientist at the NASA Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, California.
Permafrost covers a fifth of the Northern Hemisphere, having underpinned the Arctic tundra and boreal forests of Alaska, Canada and Russia for millennia. It serves as a kind of time capsule, preserving — in addition to ancient viruses — the mummified remains of a number of extinct animals that scientist have been able to unearth and study in recent years, including two cave lion cubs and a woolly rhino.
The reason permafrost is a good storage medium isn’t just because it’s cold; it’s an oxygen-free environment that light doesn’t penetrate. But current day Arctic temperatures are warming up to four times faster than the rest of the planet, weakening the top layer of permafrost in the region.
To better understand the risks posed by frozen viruses, Jean-Michel Claverie, an Emeritus professor of medicine and genomics at the Aix-Marseille University School of Medicine in Marseille, France, has tested earth samples taken from Siberian permafrost to see whether any viral particles contained therein are still infectious. He’s in search of what he describes as “zombie viruses” — and he has found some.
THE VIRUS HUNTER
Claverie studies a particular type of virus he first discovered in 2003. Known as giant viruses, they are much bigger than the typical variety and visible under a regular light microscope, rather than a more powerful electron microscope — which makes them a good model for this type of lab work.
His efforts to detect viruses frozen in permafrost were partly inspired by a team of Russian scientists who in 2012 revived a wildflower from a 30,000-year-old seed tissue found in a squirrel’s burrow. (Since then, scientists have also successfully brought ancient microscopic animals back to life.)
In 2014, he managed to revive a virus he and his team isolated from the permafrost, making it infectious for the first time in 30,000 years by inserting it into cultured cells. For safety, he’d chosen to study a virus that could only target single-celled amoebas, not animals or humans.
He repeated the feat in 2015, isolating a different virus type that also targeted amoebas. And in his latest research, published February 18 in the journal Viruses, Claverie and his team isolated several strains of ancient virus from multiple samples of permafrost taken from seven different places across Siberia and showed they could each infect cultured amoeba cells.
Those latest strains represent five new families of viruses, on top of the two he had revived previously. The oldest was almost 48,500 years old, based on radiocarbon dating of the soil, and came from a sample of earth taken from an underground lake 16 meters (52 feet) below the surface. The youngest samples, found in the stomach contents and coat of a woolly mammoth’s remains, were 27,000 years old.
That amoeba-infecting viruses are still infectious after so long is indicative of a potentially bigger problem, Claverie said. He fears people regard his research as a scientific curiosity and don’t perceive the prospect of ancient viruses coming back to life as a serious public health threat.
“We view these amoeba-infecting viruses as surrogates for all other possible viruses that might be in the permafrost,” Claverie told CNN.
“We see the traces of many, many, many other viruses,” he added. “So we know they are there. We don’t know for sure that they are still alive. But our reasoning is that if the amoeba viruses are still alive, there is no reason why the other viruses will not be still alive, and capable of infecting their own hosts.”
PRECEDENT FOR HUMAN INFECTION
Traces of viruses and bacteria that can infect humans have been found preserved in permafrost.
A lung sample from a woman’s body exhumed in 1997 from permafrost in a village on the Seward Peninsula of Alaska contained genomic material from the influenza strain responsible for the 1918 pandemic. In 2012, scientists confirmed the 300-year-old mummified remains of a woman buried in Siberia contained the genetic signatures of the virus that causes smallpox.
An anthrax outbreak in Siberia that affected dozens of humans and more than 2,000 reindeer between July and August in 2016 has also been linked to the deeper thawing of the permafrost during exceptionally hot summers, allowing old spores of Bacillus anthracis to resurface from old burial grounds or animal carcasses.
Birgitta Evengård, professor emerita at Umea University’s Department of Clinical Microbiology in Sweden, said there should be better surveillance of the risk posed by potential pathogens in thawing permafrost, but warned against an alarmist approach.
“You must remember our immune defence has been developed in close contact with microbiological surroundings,” said Evengård, who is part of the CLINF Nordic Centre of Excellence, a group that investigates the effects of climate change on the prevalence of infectious diseases in humans and animals in northern regions.
“If there is a virus hidden in the permafrost that we have not been in contact with for thousands of years, it might be that our immune defence is not sufficient,” she said. “It is correct to have respect for the situation and be proactive and not just reactive. And the way to fight fear is to have knowledge.”
CHANCES OF VIRAL SPILLOVER
Of course, in the real world, scientists don’t know how long these viruses could remain infectious once exposed to present-day conditions, or how likely the virus would be to encounter a suitable host. Not all viruses are pathogens that can cause disease; some are benign or even beneficial to their hosts. And while it is home to 3.6 million people, the Arctic is still a sparsely populated place, making the risk of human exposure to ancient viruses very low.
Still, “the risk is bound to increase in the context of global warming,” Claverie said, “in which permafrost thawing will keep accelerating, and more people will populate the Arctic in the wake of industrial ventures.”
And Claverie isn’t alone in warning that the region could become a fertile ground for a spillover event — when a virus jumps into a new host and starts to spread.
Last year, a team of scientists published research on samples of soil and lake sediment taken from Lake Hazen, a freshwater lake in Canada located within the Arctic circle. They sequenced the genetic material in the sediment to identify viral signatures and the genomes of potential hosts — plants and animals — in the area.
Using a computer model analysis, they suggested the risk of viruses spilling over to new hosts was higher at locations close to where large amounts of glacial meltwater flowed into the lake — a scenario that becomes more likely as the climate warms.
UNKNOWN CONSEQUENCES
Identifying viruses and other hazards contained in the warming permafrost is the first step in understanding what risk they pose to the Arctic, Miner at NASA’s Jet Propulsion Laboratory said. Other challenges include quantifying where, when, how fast and how deep permafrost will thaw.
Thawing can be a gradual process of as little as centimetres per decade, but also happens more rapidly, such as in the case of massive land slumps that can suddenly expose deep and ancient layers of permafrost. The process also releases methane and carbon dioxide into the atmosphere — an overlooked and underestimated driver of climate change.
Miner catalogued an array of potential hazards currently frozen in Arctic permafrost in a 2021 paper published in the scientific journal Nature Climate Change.
Those possible dangers included buried waste from the mining of heavy metals and chemicals such as the pesticide DDT, which was banned in the early 2000s. Radioactive material has also been dumped in the Arctic — by Russia and the United States — since the advent of nuclear testing in the 1950s.
“Abrupt thaw rapidly exposes old permafrost horizons, releasing compounds and microorganisms sequestered in deeper layers,” Miner and other researchers noted in the 2021 paper.
In the research paper, Miner labelled the direct infection of humans with ancient pathogens released from permafrost as “currently improbable.”
However, Miner said she is worried about what she termed “Methuselah microorganisms” (named after the Biblical figure with the longest life span). These are organisms that could bring the dynamics of ancient and extinct ecosystems into the present-day Arctic, with unknown consequences.
The re-emergence of ancient microorganisms has the potential to change soil composition and vegetative growth, possibly further accelerating the effects of climate change, Miner said.
“We’re really unclear as to how these microbes are going to interact with the modern environment,” she said. “It’s not really an experiment that I think any of us want to run.”
The best course of action, Miner said, is to try and halt the thaw, and the wider climate crisis, and keep these hazards entombed in the permafrost for good.
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Researchers observing with NASA’s James Webb Space Telescope have pinpointed silicate cloud features in a distant planet’s atmosphere. The atmosphere is constantly rising, mixing, and moving during its 22-hour day, bringing hotter material up and pushing colder material down.
The resulting brightness changes are so dramatic that it is the most variable planetary-mass object known to date. The team, led by Brittany Miles of the University of Arizona, also made extraordinarily clear detections of water, methane and carbon monoxide with Webb’s data, and found evidence of carbon dioxide. This is the largest number of molecules ever identified all at once on a planet outside our solar system.
Cataloged as VHS 1256 b, the planet is about 40 light-years away and orbits not one, but two stars over a 10,000-year period. “VHS 1256 b is about four times farther from its stars than Pluto is from our sun, which makes it a great target for Webb,” Miles said. “That means the planet’s light is not mixed with light from its stars.”
Higher up in its atmosphere, where the silicate clouds are churning, temperatures reach a scorching 1,500 degrees Fahrenheit (815 degrees Celsius).
Within those clouds, Webb detected both larger and smaller silicate dust grains, which are shown on a spectrum. “The finer silicate grains in its atmosphere may be more like tiny particles in smoke,” noted co-author Beth Biller of the University of Edinburgh in Scotland. “The larger grains might be more like very hot, very small sand particles.”
VHS 1256 b has low gravity compared to more massive brown dwarfs, which means that its silicate clouds can appear and remain higher in its atmosphere where Webb can detect them. Another reason its skies are so turbulent is the planet’s age. In astronomical terms, it’s quite young. Only 150 million years have passed since it formed—and it will continue to change and cool over billions of years.
In many ways, the team considers these findings to be the first “coins” pulled out of a spectrum that researchers view as a treasure chest of data. In many ways, they’ve only begun identifying its contents. “We’ve identified silicates, but better understanding which grain sizes and shapes match specific types of clouds is going to take a lot of additional work,” Miles said. “This is not the final word on this planet—it is the beginning of a large-scale modeling effort to fit Webb’s complex data.”
Although all of the features the team observed have been spotted on other planets elsewhere in the Milky Way by other telescopes, other research teams typically identified only one at a time. “No other telescope has identified so many features at once for a single target,” said co-author Andrew Skemer of the University of California, Santa Cruz. “We’re seeing a lot of molecules in a single spectrum from Webb that detail the planet’s dynamic cloud and weather systems.”
The team came to these conclusions by analyzing data known as spectra gathered by two instruments aboard Webb, the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI). Since the planet orbits at such a great distance from its stars, the researchers were able to observe it directly, rather than using the transit technique or a coronagraph to take this data.
There will be plenty more to learn about VHS 1256 b in the months and years to come as this team—and others—continue to sift through Webb’s high-resolution infrared data. “There’s a huge return on a very modest amount of telescope time,” Biller added. “With only a few hours of observations, we have what feels like unending potential for additional discoveries.”
What might become of this planet billions of years from now? Since it’s so far from its stars, it will become colder over time, and its skies may transition from cloudy to clear.
The researchers observed VHS 1256 b as part of Webb’s Early Release Science program, which is designed to help transform the astronomical community’s ability to characterize planets and the disks where they form.
The team’s paper, entitled “The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b,” will be published in The Astrophysical Journal Letters.
The work is currently published on the arXiv preprint server.
More information:
Brittany E. Miles et al, The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b, arXiv (2022). DOI: 10.48550/arxiv.2209.00620
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James Webb spots swirling, gritty clouds on remote planet (2023, March 22)
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Sky-gazers will be treated to a parade of planets near the end of month when Jupiter, Mercury, Venus, Uranus and Mars will appear together in the night sky.
On March 28, a large planetary alignment will take place when the five planets appear just after sunset, all within a 50-degree sector of the sky, according to sky tracking site Starwalk.
Jupiter and Mercury will appear near the horizon, in the constellation Pisces, while Venus will be visible higher in the sky on the constellation Aries, the sky-tracking site noted.
Next, Uranus will line up nearby but a pair of binoculars may be required to get a glimpse of the planet. Finally, Mars will appear higher in the sky, near the moon, to complete the five-planet alignment.
“Although March 28 is the best day for observation, the alignment will be visible several days before and after that date,” the website explained.
If the weather isn’t in your favour next week, there will be other opportunities to catch a planetary alignment this year, including another five-planet alignment on June 17. Mercury, Uranus, Jupiter, Neptune, and Saturn will be on parade that evening.
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Next year, 2024, is Solar Eclipse Year.
On April 8, 2024, a total solar eclipse will be visible from the south Pacific Ocean, northern Mexico, across the U.S. and through the Atlantic provinces of Canada.
More importantly, the total solar eclipse will be visible from southwestern Newfoundland, in the areas of Stephenville and across central Newfoundland through Terra Nova Park and Gander.
A partial eclipse will be visible across the province, with St. John’s and Corner Brook just outside the range of a total eclipse, an 80 per cent eclipse in Labrador City and a 70 per cent eclipse in Nain.
The 2024 solar eclipse will be the first eclipse crossing the province since 1970 and the only one until 2079.
For many, this is a once-in-a-lifetime event to see a total solar eclipse in Newfoundland and Labrador.
“Solar eclipses are special events in many cultures and have allowed scientists to make great discoveries.”
We are fortunate to even be able to observe a solar eclipse.
The Earth is the only place in our solar system where there is a moon that is about the same size in the sky (0.5 degree) as the sun.
Solar eclipses are special events in many cultures and have allowed scientists to make great discoveries.
When the moon passes in front of the sun, most of the light is blocked and we can see the sun’s corona (more about the corona below).
A note: make sure to wear appropriate eye protection during an eclipse to look at the sun.
The late Dr. Jay Pasachoff, an American astronomer, was so inspired by solar eclipses that he chased them around the world to experience more than 70 eclipses in about 50 years.
In a New York Times 2010 op-ed, he wrote: “There’s also the primal thrill this astronomical lightshow always brings the perfect alignment, in solemn darkness, of the celestial bodies that mean most to us.”
There is the thrill of observing solar eclipses and there is the thrilling science of them, too.
Thanks to solar eclipses, we learn about the sun’s corona, a thin layer of plasma that is just above the sun’s surface.
We normally can’t see it because it is so thin and has such a small density, but the temperature of the corona is about one million degrees Celsius.
It is believed that the corona is related to the sun’s magnetic field and to things like solar flares and mass ejections.
These flares and mass ejections impact the Earth through space weather and the aurorae — phenomena that those of us in the Northern Hemisphere recognize as the Northern Lights.
Scientific discovery
And it’s not just the sun.
Solar eclipses were important to provide some of the early evidence of Albert Einstein’s Theory of General Relativity.
Einstein predicted that light is bent by the gravity of stars.
So, if we can see stars behind the sun, they will appear to be in a slightly different location in the sky relative to each other than when we see them normally.
In 1919 scientists observed stars behind the sun that became visible during a solar eclipse and found that, indeed, their observations agreed with Einstein’s theory.
Town of Gander a major partner
Solar eclipses are fantastic events that connect humans to nature, celestial bodies and to the universe.
Next year’s celebration is an opportunity to celebrate science, nature and humanity.
Thanks to the enthusiasm and excitement of its staff and council, Prof. Svetlana Barkanova, Department of Physics, Grenfell Campus, and I are partnering with the Town of Gander to host a solar eclipse viewing party on April 8, 2024, and a science festival in the days before the eclipse.
The town is excited to be a major partner bringing people from across Newfoundland and Labrador to learn, discover and experience a total solar eclipse together.
The town has pledged to develop a budget to assist with the costs of this unique science festival, along with providing facilities, viewing sites and in-kind assistance.
The event is being planned in collaboration with a continuing science and community outreach program led by Prof. Barkanova and her team.
They deliver a large-scale scientific and cultural outreach program for youth in our province, especially rural youth, girls and Indigenous students, and is currently developing in-person and online seminars and workshops leading up to the solar eclipse.
“It is an ideal chance for us at Memorial to do what we do best — share what is great about our fields.”
This is a call to faculty, students and staff at Memorial University across all campuses to join in the celebration and help it grow and expand.
Not only will we have the opportunity to experience an amazing celestial event, it is a chance to come together in central Newfoundland and share the stories of what we do at Memorial from how we understand the sun and moon in astrophysics, in cultures, in literatures, in humanities and so on.
This is a call to action for your involvement; more participating colleagues means more public talks, Science on Tap events, outreach in schools and more.
It is an ideal chance for us at Memorial to do what we do best — share what is great about our fields and do so around this rare event in Newfoundland and Labrador.
Come join in for Solar Eclipse Year 2024 in Gander. Contact me via email.
Co-authored by Dr. Svetlana Barkanova, Department of Physics, Grenfell Campus, and Brian Williams, tourism development officer, Town of Gander.
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