The story begins with a cartoon. In late 1987 a low-budget animated series called Teenage Mutant Ninja Turtles began airing on American children’s television, and within eighteen months it had become the most successful children’s franchise of its decade. Sales of turtle-themed toys, lunchboxes, video games, and Halloween costumes went through the roof. And so did sales of actual pet turtles. American reptile farms, most of them clustered along the Mississippi River basin where the red-eared slider is native, ramped up production to meet the demand. Hatchlings the size of a fifty-cent piece were shipped by the tens of millions to pet stores across the United States and around the world.

What almost nobody selling the turtles bothered to mention was that a hatchling red-eared slider grows into an adult red-eared slider weighing up to three kilograms, requiring a hundred-gallon tank with filtration, and living for forty years or longer. Within a few years, unwanted adult sliders started turning up in ponds, rivers, and public parks in countries where the species had never existed before.

How 52 million turtles left the country

According to the International Union for Conservation of Nature’s Global Invasive Species Database entry on Trachemys scripta elegans, compiled by the IUCN Species Survival Commission’s Invasive Species Specialist Group and citing the original Telecky 2001 tally of the United States pet turtle export trade, more than 52 million red-eared sliders were exported from American turtle farms to overseas pet markets between 1989 and 1997. The primary destination was China, though large numbers also went to Japan, Taiwan, Thailand, South Korea, and Singapore, along with substantial shipments to France, Spain, Italy, Germany, the United Kingdom, Australia, South Africa, and Brazil. The reason American farms could produce sliders at that scale was that the species is remarkably easy to breed in captivity. The reason they were so easy to ship was that a hatchling turtle weighs almost nothing and can be packed into ventilated boxes by the hundreds.

The European Union, watching this happen in real time, banned the import of Trachemys scripta elegans on 22 December 1997. That single regulatory decision effectively ended the American export trade to Europe overnight. By the time it came into effect, however, the damage across the European continent was already done. Feral populations had established themselves in France, Spain, Italy, Portugal, Slovenia, Greece, Germany, Austria, Switzerland, the Netherlands, Belgium, Poland, Latvia, and the United Kingdom. Similar populations were showing up in the wetlands of every country the trade had reached. The turtles that had already been sold were still alive. Their owners were still tiring of them. The ponds behind their houses were still available.

If our animal kingdom fascinates you, you’ll enjoy this video we made on the recorded adventure of a young elephant bull, and what his route revealed: 

What happens when a tank turtle meets a lake

The red-eared slider turns out to be an unusually well-equipped invader. It reaches sexual maturity in three to four years, which is faster than most native freshwater turtles it competes with. Females can lay up to six clutches per year of up to thirty eggs each, giving the species a reproductive rate roughly two or three times higher than the European pond turtle it is now displacing across much of the continent. Adults tolerate a wide range of water conditions, from clean rural rivers to heavily polluted urban canals. They are omnivorous and will eat almost anything a freshwater environment can offer. They are aggressive at basking sites and will physically displace smaller native turtles from the sunning logs they need for thermoregulation.

The competitive dynamic has been most extensively studied in France, where researchers from the University of Paris-Sud have been documenting the interaction between introduced sliders and the native European pond turtle (Emys orbicularis) for the past two decades. What they have found is that in ponds where sliders are present, the native pond turtles are pushed to lower-quality basking sites, tend to survive at lower rates, and produce fewer offspring per breeding season. The European pond turtle is classified as Near Threatened on the IUCN Red List. Every additional slider in a European wetland adds to the pressure. Similar competitive displacement has been documented in Washington State against the Pacific pond turtle, in Australia against native short-necked turtles, and across Asia against a dozen freshwater species that had evolved in the absence of anything resembling a Mississippi-basin generalist.

According to The Nature Conservancy’s 2019 Cool Green Science article on American species invading other countries, written by staff science journalist Justine E. Hausheer, the geographic reach of the red-eared slider now covers essentially every continent where freshwater habitat and moderate temperatures exist. Established feral populations have been confirmed in the western United States, Australia, New Zealand, Europe, Great Britain, South Africa, the Caribbean, the Middle East, Southeast Asia, and several Pacific island groups. Only Antarctica remains slider-free, and even that exemption is only because Antarctica has no freshwater ponds and does not get above freezing for most of the year. If it did, and it had ponds, the sliders would probably be there too.

The IUCN Species Survival Commission’s Invasive Species Specialist Group formally listed the red-eared slider on the Global Invasive Species Database’s roster of the hundred worst invasive species anywhere in the world. The species now ranks number 93 on that list. It sits alongside brown rats, feral cats, cane toads, and the emerald ash borer as a species whose global spread has caused measurable and lasting ecological harm. Australia’s Vertebrate Pests Committee has assigned it a threat category of EXTREME. Multiple European countries have banned its sale, its keeping as a pet, or both. Illegal shipments continue anyway. Buddhist mercy ceremonies in parts of East Asia continue to release captive-bred sliders into rivers as an act of religious devotion, unaware or unbothered that the specific animal being released is an invasive species that will outcompete the native turtles the ceremony was originally designed to protect.

What the whole episode represents is one of the more improbable ecological consequences of a late-1980s children’s television programme. The Ninja Turtles cartoon ran for ten years. American reptile farms produced tens of millions of live turtles to meet the resulting demand. The turtles grew larger than their owners expected. The owners released them into the nearest available water. And forty years later, a native North American reptile that once occupied the freshwater ponds of a few states along the Gulf Coast now occupies almost every freshwater pond on the planet warm enough to support it. The turtles never asked to be there. They just weren’t given much choice. And once they arrived, they turned out to be remarkably well-suited to staying.

The post Between 1989 and 1997 the United States shipped more than 50 million pet turtles abroad, and enough of the red-eared sliders were later dumped in ponds and rivers when they grew too big that the species now outcompetes native turtles on every continent but Antarctica, listed among the 100 worst invaders on Earth. appeared first on Space Daily.

The International Space Station has been in continuous crewed operation since November 2000, which means somebody has been living roughly four hundred kilometres above the surface of the Earth every single day for the past twenty-five years without a break. During that time the station has been visited by more than two hundred and eighty astronauts and cosmonauts from more than twenty countries, and each of them has faced the same practical problem that any long-term resident of anywhere eventually has to solve.

Their clothes get dirty. And the space station, for reasons that come down to the physics of orbital resupply, does not have and has never had a washing machine on board. What NASA and the Russian space agency have therefore developed over the intervening decades is one of the more counterintuitive laundry solutions in any modern human institution. There is no laundry. The clothes go into a cargo capsule when the astronauts are done with them. The cargo capsule burns up on the way home.

Why nobody bothered to send a washing machine up

The reason is water. Aboard the space station every drop of water is a precious resource that either has to be lifted up from Earth at roughly $10,000 per kilogram in launch costs, or has to be extracted and recycled from the crew’s own urine, sweat and exhaled breath through a purification system that operates continuously in the background of station life. The station recycles roughly 90 per cent of the water it produces internally, which is considerably better than any comparable industrial recycling system on Earth. But even at that recycling rate, adding a washing machine to the water demand of the station would consume enough additional water per cycle to fundamentally change the economics of resupply. According to a 2017 VICE interview with Robert Trevino, a senior engineer with NASA’s Crew and Thermal Systems Division who is responsible for astronaut clothing on the station, the engineering team has been examining this question for years. NASA’s own internal trade studies compared the water and power requirements of a hypothetical station laundry system against the cost of simply replacing dirty clothes with fresh ones sent up on cargo runs. Replacing the clothes turned out to be cheaper. So that is what NASA does.

If space exploration fascinates you, you’ll enjoy this video we made on why astronauts come home feeling like they’re being watched…

What this means in practical terms is that astronauts on the station wear each piece of clothing for as long as it can reasonably be worn before it becomes unusable. Exercise clothes get roughly two weeks of use because the mandatory hour of daily exercise required to prevent bone and muscle loss in microgravity produces enough sweat to defeat the antibacterial coating on the fabric within a fortnight. Regular daily-wear clothes, meaning the cotton polos and cargo shorts that most station astronauts prefer, get anywhere between one and three months of wear per garment. Underwear rotation is up to the individual crew member. Trevino told VICE that former astronaut Don Pettit was known to have worn the same pair of shorts for months at a stretch, which was apparently a source of considerable amusement among his crewmates. The clothing is sourced by NASA’s contractor Lockheed Martin from ordinary commercial suppliers, including Lands’ End, Cabela’s, and Blackhawk. There is nothing technologically special about the fabric.

Where the clothes actually end up

Once a garment has reached the end of its useful wearing life, it goes into the station’s waste system alongside the packaging, food waste, expired equipment, and general trash that the crew generates every day. The waste is bagged, taped, and stored in whichever visiting cargo vehicle happens to be docked at the time. There are currently three different cargo vehicles that regularly deliver supplies to the station. Russia’s Progress capsule and Northrop Grumman’s Cygnus vehicle are both single-use, meaning they are launched from Earth full of supplies, unloaded at the station, refilled with trash, undocked, and then deliberately deorbited over the Pacific Ocean where they burn up in the upper atmosphere on the way down. SpaceX’s Dragon capsule is the exception. It is reusable, and it returns to Earth intact via parachute for a splashdown in the Pacific and eventual reuse on a subsequent mission. So while Dragon comes home in one piece, the trash from every Progress and Cygnus run ends up as a spectacular fireball crossing the sky somewhere in the upper atmosphere above the South Pacific.

According to Space.com’s November 2023 reporting by managing editor Brett Tingley on the reentry of the Russian Progress MS-23 cargo spacecraft, the reentry of a fully loaded trash-carrying capsule is a visually striking event. The Progress MS-23 undocked from the station on 29 November 2023 carrying, in the words of the Roscosmos cosmonaut Oleg Kononenko who saw it off, “old equipment and household waste, or everything the experts have decided to toss from the station.” Four hours later NASA astronaut Jasmin Moghbeli, who had been alerted by mission control to look out of a specific window at a specific time, was able to photograph the reentry from the ISS itself. Her photographs show what looks like a spectacular meteor. Bright trails of fire streak across the darkness of the upper atmosphere. The main capsule breaks apart into several distinct fragments as the atmospheric heating destroys its structural integrity. Then everything disperses into smaller and smaller sparks until nothing recognisable is left. Moghbeli wrote on X afterwards that the whole event lasted only two or three minutes and reminded her of fireworks.

What was inside the capsule during those two or three minutes was, among many other things, the accumulated clothing that seven astronauts and cosmonauts on the station had been wearing over the preceding several months. Somewhere in the fireball was Kononenko’s old exercise gear, along with the daily-wear cotton polos of the American, Japanese, and Danish crew members who had been aboard during the same period. Whether any of the specific garments in question had been observed by anyone on the ground as bright flashes in the night sky is impossible to say with certainty. But the fireball that briefly crossed the upper atmosphere above the South Pacific on the evening of 29 November 2023 did in fact contain, among its many other contents, the discarded underwear of at least seven people who had been living in low Earth orbit at the time.

Which is to say that the surprising claim in the title turns out to be more or less exactly what actually happens. The station has no washing machine. The clothes get worn until they can’t be worn any longer. They get packed into whichever cargo vehicle is next scheduled to depart. And the cargo vehicle, on its final trajectory back through the upper atmosphere, becomes a briefly visible streak of light in the night sky before the whole thing burns away to nothing over the Pacific Ocean. If you happen to be looking up at the right moment from the right latitude, and if you know the timing of the current Progress or Cygnus deorbit schedule, you might catch one. And what you would be watching, in the strict literal sense, is somebody’s old socks and shirts on their final journey home.

The post Astronauts on the space station have no washing machine, because water is far too precious to waste on laundry, so they wear the same clothes for days and then pack the dirty ones into a cargo capsule that burns up on reentry, which means a fireball crossing the sky could, in theory, be a bundle of an astronaut’s old underwear. appeared first on Space Daily.

When NASA deployed the Long Duration Exposure Facility in April 1984, its experiments were supposed to spend about ten months in orbit before returning to Earth. Instead, scheduling changes and the aftermath of the Challenger accident extended the flight to 69 months. Columbia finally collected the facility in January 1990 and carried it home in its payload bay.

The satellite held 57 experiments. Its name, usually shortened to LDEF, described the job: expose materials and equipment to space, then bring them back for examination. The unexpectedly long stay made recovery more urgent while also providing an unusually extensive record of what the orbital environment could do.

A laboratory whose exterior was part of the experiment

LDEF was an uncrewed structure built to travel to and from orbit inside a space shuttle. A NASA mission profile describes a facility roughly nine metres long and 4.3 metres across, passively stabilised so its surfaces retained a consistent orientation relative to its direction of travel.

That orientation was scientifically useful. Materials facing into the direction of motion did not receive the same exposure as those facing away. A sample’s location was therefore part of the experiment, alongside its composition and the length of time it spent outside.

The structure carried test specimens in trays. Some investigations concerned the space environment itself; others asked how materials, components or systems would respond to prolonged exposure. The facility did not need a crew working inside it to function as a laboratory.

Its surfaces were recording the journey.

Returning those surfaces allowed scientists to study changes that could not be fully understood from a photograph alone. They could examine the actual material, compare exposed and protected areas, and connect physical damage with where each specimen had flown.

A retrieval delayed more than once

NASA’s history of the STS-32 recovery mission traces the postponements. Retrieval was originally assigned to a flight in February 1985. Shuttle scheduling delays pushed it to September 1986, and the Challenger accident brought another, much longer interruption.

By the time Columbia was preparing to collect LDEF, its orbit was decaying. NASA’s retrospective says trajectory specialists expected atmospheric re-entry by March 1990, making a timely recovery important. An object designed to be returned for analysis could otherwise lose both its hardware and much of its scientific value.

The long delay should not be mistaken for a planned six-year exposure campaign. It changed the experiment’s conditions after launch. More exposure could reveal long-term effects, but it also meant investigators had to interpret results against a mission history different from the one they had prepared for.

Nor did every instrument necessarily record continuously for the entire stay. The physical exposure of a specimen and the recording lifetime of an active instrument are separate things.

Columbia brought back the whole facility

On 12 January 1990, Columbia’s crew retrieved LDEF. Bonnie Dunbar operated the shuttle’s robotic arm, and the astronauts carried out a photographic survey before securing the facility in the cargo bay. Columbia landed at Edwards Air Force Base on 20 January.

A post-flight technical report records 32,422 orbits during the extended mission. Once the facility was back on Earth, work shifted from catching a satellite to systematically documenting and removing its experiments.

That transition was essential. Recovery was the route to the measurements, not the end of them. Trays had to be identified and examined in relation to their positions on the structure, while investigators distinguished environmental effects from other possible changes.

A spacecraft that returns as cargo offers a different scientific opportunity from one that transmits readings and stays aloft. The sample itself remains available for instruments, techniques and questions that may go beyond the original flight equipment.

Weathering in space has several causes

NASA’s overview of LDEF lists micrometeoroids, orbital debris, energetic particles, atomic oxygen and solar radiation among the exposures the experiments encountered. Calling the surfaces weathered is useful shorthand, but this was not terrestrial weather acting on an abandoned machine.

Atomic oxygen is one particularly important part of low Earth orbit. NASA’s materials research explanation describes how these reactive oxygen atoms can erode polymers on spacecraft surfaces. Their cumulative effects matter when engineers choose materials intended to remain outside for years.

Research from LDEF experiment A0114 included measurements of oxidation and polymer erosion, using the returned samples to investigate how surfaces interacted with fast oxygen atoms. Such measurements turned visible wear into evidence about rates and mechanisms.

The damage was part of the data.

Different materials could respond differently, and a surface’s appearance could not by itself identify every process involved. The value lay in combining inspection with measurements and the known exposure history.

The extended stay left an engineering reference

A 1994 overview of LDEF results describes more than 10,000 test specimens and the work of investigators studying the returned hardware and recorded data. The findings helped refine models of radiation, debris, meteoroids and atomic oxygen in low Earth orbit.

That is the broader importance of the mission. A laboratory test on Earth can isolate a particular effect, but an orbiting specimen encounters several influences together. Returned hardware allows researchers to compare their predictions with the combined result.

LDEF’s unusually long stay was an operational complication that became a source of scientific evidence. Columbia did more than retrieve an overdue satellite: it delivered years of exposure back to the laboratories equipped to examine it, with the marks of that history still on the surfaces.

The post In 1984, NASA left a satellite carrying 57 experiments in orbit for a planned 10 months — repeated delays stretched the trip to 69 months before Columbia brought the entire laboratory home inside its cargo bay, its exposed surfaces weathered by years in space. appeared first on Space Daily.

The Apollo 11 mission cost NASA more than twenty billion dollars in 1969 money, or somewhere north of one hundred and fifty billion dollars in modern terms. It was one of the most expensive single scientific undertakings in human history, involving roughly four hundred thousand people across NASA and its contractor network. Everything about it was unprecedented. The Saturn V rocket had never been flown with a crew on a full lunar trajectory before. The Lunar Module had never been landed on a celestial body. The re-entry profile at the return end of the trip had never been survived. Buzz Aldrin flew on the mission as the second of three crew members and walked on the lunar surface on 20 July 1969. He returned home four days later. And when he got back to Houston he filed a routine federal government travel expense claim like any other public employee returning from a work trip. It was for thirty-three dollars and thirty-one cents.

What the voucher actually itemises

Aldrin posted a photograph of the original voucher on Twitter on 30 July 2015 to mark the forty-sixth anniversary of the moon landing. According to CBS News reporting the following day by science journalist Amanda Schupak, the voucher covers the period from 7 July 1969 through to 27 July 1969, which is a week and a half before the launch through to three days after the splashdown. What follows is probably the strangest business trip itinerary in the history of American federal expense accounting. The listed points of travel are Houston, Texas to Cape Kennedy, Florida on 7 July, then Cape Kennedy to Moon on 16 July, then Moon to Pacific Ocean on 24 July, then Pacific Ocean to Hawaii the same day, and finally Hawaii back to Houston on 27 July. The mode of transport listed for each leg is equally striking. Government Air for the two flights inside the continental United States. Government Spacecraft for the leg between Cape Kennedy and the Moon. USS Hornet, which is the aircraft carrier that recovered the crew, for the leg between the Pacific Ocean and Hawaii. And a US Air Force plane for the return to Houston.

The life of an astronaut is truly fascinating – check out the video we made on what every astronaut sees in the mirror:

The federal expense reimbursement system in 1969 did not distinguish between astronauts and any other government employee. If you were travelling on official business you filled out the same form, listed the same route, claimed the same mileage rate for personal vehicle use, and provided the same receipts for any out-of-pocket costs. Aldrin’s voucher was processed by a routine NASA finance office alongside vouchers from technicians attending conferences and administrators travelling to Washington. Nobody appears to have thought the situation odd enough to route it through any special channel. The reimbursement was paid in the normal course of business a few weeks later.

Why the amount was so small

The reason the total came to only thirty-three dollars and thirty-one cents rather than something more substantial is spelled out on the voucher itself. According to BBC Science Focus Magazine’s August 2015 write-up by Rachel Baxter, the document states in plain text that government meals and quarters were furnished for all the dates in question. That covered his food and lodging at the pre-launch quarantine facility at Cape Kennedy, aboard the Saturn V and the Apollo capsule, on the lunar surface itself, aboard the USS Hornet during the post-splashdown recovery, and inside the mobile quarantine facility where he and Neil Armstrong and Michael Collins were confined for twenty-one days after their return in case they had brought back any unknown lunar pathogens. The federal government had covered every one of those things directly, so Aldrin had nothing to claim against any of them.

What the thirty-three dollars and thirty-one cents actually covered was almost certainly the mileage rate for driving his own personal vehicle from his home in Houston to Ellington Air Force Base and back at each end of the trip. Government employees in 1969 were entitled to claim a per-mile rate when using their own car for official business. Aldrin did what everybody at NASA did. He drove to the airfield, got on the government plane, and came home the same way at the end. He submitted his mileage on the standard form. He got his check for thirty-three dollars and thirty-one cents in the mail a few weeks later.

The voucher was not the only piece of Apollo 11 bureaucratic paperwork Aldrin dug out and shared publicly in 2015. He also posted the US Customs declaration that he and Armstrong and Collins had signed on landing in Honolulu after the recovery. The declaration listed their country of departure as Moon and their flight number as Apollo 11. The cargo section listed moon rock and moon dust samples. The question about whether any crew member had been in contact with an infectious disease during the trip was answered by Aldrin in the space provided as “moon disease TBD.” A Honolulu customs inspector had counter-signed the form and accepted it as filed. The crew had cleared customs.

What the whole set of documents represents is one of the more revealing curiosities of the entire Apollo programme. NASA had achieved something in July 1969 that no human institution had ever previously come close to achieving, and the federal bureaucracy processing the paperwork for the people who had done it treated them exactly like every other federal employee returning from a work trip. That was partly because the routine forms were the only ones available. But it was also because the people at NASA didn’t consider themselves exempt from the ordinary paperwork obligations of federal employment. Aldrin filled out his expense form. He submitted his customs declaration. He collected his thirty-three dollars and thirty-one cents. And forty-six years later he still had the voucher in a drawer.

The post The second man to walk on the Moon later dug out his old expense claim from the trip, and it turns out Buzz Aldrin was reimbursed the grand sum of 33 dollars and 31 cents, not for the rocket or the spacecraft, but for the ordinary travel expenses of getting himself to and from the launch site like any other business trip. appeared first on Space Daily.

The Metropolitan Transportation Authority, which runs the New York City subway system, had a problem in the late 1990s. It was in the middle of a major fleet modernisation programme that was going to retire roughly two and a half thousand ageing subway cars over the following decade. These were mostly the red-painted R-33 and R-36 cars that generations of New Yorkers had ridden through the 1970s, 80s and 90s, followed by the older stainless steel Brightliners that would come off the tracks later. Each retired car was worth essentially nothing as scrap. Each also cost the MTA roughly twelve thousand dollars to dispose of through conventional demolition. Which meant the total disposal bill for the fleet retirement, at prevailing rates, was going to run to something north of thirty million dollars. And the MTA, being a public transit authority in a permanent state of budget crisis, was not enthusiastic about that particular expense.

The solution the agency arrived at, in partnership with a handful of coastal state governments and the U.S. Fish and Wildlife Service, was one of the more counterintuitive recycling programmes of the early twenty-first century. Instead of paying to demolish the cars, the MTA would clean them, ship them south by rail and barge, and drop them into the ocean off the eastern seaboard. There they would form artificial reefs. The states would get new marine habitat for essentially free. The MTA would save the disposal costs. And the fish would, in theory, work out what to do with the rest.

How you turn a subway car into a reef

According to the New York Transit Museum’s own summary of the MTA Artificial Reefing Program, produced in collaboration with the programme’s former director Michael Zacchea and Robert Martore of the South Carolina Department of Natural Resources, the operation ran from August 2001 through to April 2010 and deployed more than 2,500 deaccessioned train cars to underwater sites off the coasts of New Jersey, Delaware, Virginia, South Carolina, and Georgia. The first phase concentrated on the Redbird fleet, which was already being pulled off the tracks in 2001, and which had a particularly recognisable red livery that made the sunken cars a photographable subject long after they had gone down. The Delaware Bay took approximately six hundred and nineteen Redbird cars alone, at a site now known as the Redbird Reef, located sixteen and a half nautical miles off Indian River Inlet at a depth of around eighty feet. Subsequent phases involved the stainless steel Brightliner fleet, which was deployed at reef sites further down the coast through the second half of the decade.

The engineering of the actual reef deployment was not trivial. Each car had to be stripped down first. According to the New Jersey Division of Fish and Wildlife’s own news bulletin on the deployment of 44 stainless steel subway cars at the Atlantic City Reef site in April 2008, every car went through a full preparation process before it went into the water. Windows were removed. Wiring was pulled out. Plastic components, degradable materials, hydraulic fluids, oils, and grease were all stripped or drained. The remaining shell was inspected to make sure that when the car eventually corroded, nothing toxic would leach into the surrounding marine environment. Only after that inspection was the cleaned steel body loaded onto a barge and towed offshore.

The actual sinking process was almost comically straightforward. The cars, weighing around eighteen tonnes each in their prepared state, were rolled off the deck of the barge by a hydraulic tipping mechanism and simply dropped through the water column to the seabed below. The MTA covered all of the cleaning, transport, and deployment costs. Individual cars in the New Jersey deployment measured roughly sixty feet long, ten feet wide, and eleven feet tall. Deployed in tight clusters at pre-selected coordinates, they formed roughly the same kind of hard-structure habitat that a natural rocky reef would offer, but at a scale and geometry that had never previously existed on the sandy Atlantic continental shelf.

What the fish did with them

What happened next surprised the marine biologists monitoring the sites, though it probably shouldn’t have. The subway car reefs, unlike almost any natural feature of the mid-Atlantic seabed, offered vertical structure. They offered cavities and shelter. They offered hard surfaces for sessile organisms to colonise. And they were essentially unlimited in supply. Marine invertebrates began settling on the exposed steel within weeks. Barnacles arrived. Blue mussels followed. Sponges and soft corals began to establish themselves on the vertical surfaces. Within a year or two, the once-bare metal shells of the retired subway cars had become the physical scaffolding of thriving benthic communities that had not existed anywhere on that stretch of ocean floor beforehand.

The fish arrived in response. Delaware’s Department of Natural Resources and Environmental Control has since documented that the invertebrate communities colonising the artificial reef structures provide up to four hundred times more food per square foot than the bare sandy ocean floor they replaced. Species that had been effectively absent from the region because of the lack of suitable habitat began to appear regularly at the sites. Sea bass, tautog, tuna, mackerel, flounder, scup, and triggerfish were all documented in significant numbers within a few years of the deployments. Recreational fishing operators in the coastal towns of Delaware, New Jersey, and Virginia found their nearshore catches rising. Dive operators found themselves with a genuinely unusual attraction to offer. The sunken subway cars, which had cost the MTA nothing to dispose of and had cost the states essentially nothing to acquire, became one of the more productive artificial reef complexes anywhere on the North American Atlantic coast.

The programme was not without complications. Inspection reports from New Jersey in 2009 found that some of the newer stainless steel subway cars were showing significant structural damage after only a few years underwater, which prompted the state to pause further stainless steel deployments while investigations continued. Not every car remained intact. Not every deployment site delivered the ecological returns the biologists had hoped for. And the specific question of whether artificial reefs simply concentrate existing fish populations rather than creating new ones is still debated within the marine biology community. But the general pattern held across the majority of the deployment sites through the 2010s and 2020s. The bare sand became structured habitat. The structured habitat became invertebrate communities. The invertebrate communities became feeding grounds. And the feeding grounds became fisheries.

By the time the programme officially ended on Earth Day 2010, 2,580 New York subway cars had been placed on ocean reef sites along the eastern seaboard of the United States. The MTA had saved something close to thirty million dollars in disposal costs. Delaware alone had received nearly a thousand of them. The Redbird Reef off Slaughter Beach now covers roughly 1.3 square miles of what used to be featureless sand and is one of the most biologically productive stretches of continental shelf in the entire mid-Atlantic region. Which is a strange kind of legacy for a fleet of subway trains that once carried millions of people through the tunnels underneath Manhattan and Queens. The trains never made it to the recycling yard. They made it to the ocean floor instead. And the fish have been living in them ever since.

The post More than 2,500 retired New York subway cars were dropped into the Atlantic between 2001 and 2010, not as illegal dumping but as a planned reef programme, and marine biologists who kept watch found the sunken trains quickly turned into some of the richest artificial habitats along the eastern seaboard. appeared first on Space Daily.

A telescope with no moving parts, stationed in the mountains of British Columbia, has produced the largest single accounting of fast radio bursts ever assembled. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) and its FRB collaboration have released a second catalog logging 4,539 fast radio bursts from 3,641 distinct sources, drawn from more than five years of continuous sky-watching between July 25, 2018, and September 15, 2023.

The result, posted to arXiv in January 2026 and published in The Astrophysical Journal Supplement Series, supersedes the collaboration’s first catalog, which covered a single year of observations ending in mid-2019 and recorded 536 bursts. The new release spans roughly five times the observing period and delivers more than eight times as many detected events, cementing CHIME’s role as the dominant instrument for cataloging these millisecond-long flashes of radio energy.

A telescope that cannot look anywhere else

CHIME’s design is unusual for an instrument that has become the world’s leading fast radio burst detector. Located at the Dominion Radio Astrophysical Observatory near Penticton, British Columbia, it consists of four stationary half-pipe reflectors, each 100 meters long and 20 meters wide, laid side by side and oriented north-south. ICHIME has no moving parts at all — unlike dishes that swivel to track a target. Each cylinder’s focal line is strung with 256 dual-polarization antennas, for 1,024 across the array, feeding a digital signal-processing system that forms 1,024 beams electronically rather than through any physical steering.

That fixed geometry means CHIME cannot be aimed at a particular patch of sky the way a conventional radio dish can. Instead, it watches a roughly 200-square-degree strip of sky directly overhead and lets Earth’s rotation carry the rest of the northern sky through its field of view over the course of a day. The technique, known as transit observing, trades the ability to target specific objects on demand for near-continuous coverage of a wide swath of sky, night and day — precisely the kind of monitoring that catching rare, unpredictable millisecond bursts requires.

What changed since the first catalog

The collaboration’s first catalog, released in 2021, logged just over 500 bursts from a single year of data. That release established CHIME as a serious FRB survey instrument and provided the first large, uniformly selected sample for statistical study. The new catalog is a different scale of effort entirely: it folds in more than four additional years of observing time, past the original one-year window, and pushes the source count past 3,600 — a population increase that lets researchers move from spotting a phenomenon to characterizing it as a class.

Fast radio bursts are intense pulses of radio waves lasting typically a few milliseconds, first identified in archival data in 2007 and confirmed as an astrophysical population in the years since. Most detected bursts appear to flash once and never repeat from the same location, but a minority repeat, sometimes many times, from sources that can be pinpointed to host galaxies. Among the 4,539 bursts in the new catalog, 981 come from 83 known repeating sources, while the remainder appear as one-off events, at least within the observing window. That repeater fraction, drawn from a sample nearly nine times larger than before, gives researchers a substantially firmer basis for comparing the properties of repeating and apparently non-repeating bursts, including their durations, frequency structure, and the dispersion imposed on the signal as it crosses intervening plasma on its way to Earth.

Why the larger sample matters

The physical origin of fast radio bursts remains only partly settled. Magnetars — neutron stars with extraordinarily strong magnetic fields — are the leading candidate source for at least some bursts, following the 2020 detection of a burst from a magnetar inside the Milky Way. But the diversity of burst durations, brightness, and repetition behavior recorded across thousands of events suggests more than one physical mechanism, or more than one class of source, may be responsible. Larger, more uniform catalogs let researchers test that diversity statistically rather than relying on a handful of well-studied individual sources.

Because each burst’s radio signal is dispersed — delayed by different amounts at different frequencies as it passes through free electrons in space — the catalog also functions as a probe of matter distributed between galaxies. That diffuse, low-density gas is difficult to detect by any other means, and a sample of thousands of bursts at known or estimated distances allows astronomers to map its distribution across large volumes of the universe, an application sometimes described as using fast radio bursts to weigh the cosmos.

The catalog paper reports each burst’s arrival time, dispersion measure, scattering timescale, and flux density, along with a dynamic spectrum across the 400–800 megahertz band CHIME observes, at just under a millisecond time resolution. That level of detail, applied uniformly across thousands of bursts rather than compiled from disparate instruments and detection methods, is what distinguishes a catalog release from a series of individual discovery announcements.

What comes next

CHIME/FRB’s outrigger stations — companion antenna arrays built at separate sites across North America — extend the core telescope’s ability to localize individual bursts to their host galaxies with far greater precision than CHIME alone can achieve, a capability that has already been applied to a subset of local-universe bursts drawn from the same multi-year dataset. As those outriggers accumulate their own detections alongside the main array, the size and precision of future catalogs are expected to grow further, sharpening the statistical picture the second catalog has already begun to draw.

The post Four fixed half-pipe reflectors in British Columbia, each 100 meters long and strung with 1,024 antennas, watched the same overhead strip of sky from July 25, 2018 to September 15, 2023 and logged 4,539 fast radio bursts from 3,641 separate sources, on a telescope that cannot be aimed. appeared first on Space Daily.

For about one second after two neutron stars collided 130 million light-years away, the wreckage they left behind was hotter than anything else in the observable universe. Bhupal Dev, a physicist at Washington University in St. Louis, and four collaborators asked what that one second would have manufactured if a hypothetical particle called an axion-like particle exists — and then went looking for the light it should have left behind.

Nothing arrived. The shape of that absence is the result.

What GW170817 actually was

On 17 August 2017, the LIGO and Virgo detectors recorded a gravitational-wave chirp lasting roughly 100 seconds, the longest signal captured to that point. About 1.7 seconds later, NASA’s Fermi Gamma-ray Burst Monitor caught a short gamma-ray burst from the same patch of sky. The coincidence is documented in the collaboration’s multi-messenger paper in The Astrophysical Journal Letters.

Less than eleven hours after the merger, the one-metre Swope Telescope in Chile pinned the source to NGC 4993, a lenticular galaxy about 40 megaparsecs — roughly 130 million light-years — away. Within a day, dozens of observatories were watching a fading point of light that astronomers had spent decades predicting and never seen: a kilonova.

Two neutron stars had spiralled into each other, each somewhere between about one and two times the mass of the Sun, each compressed into an object about the size of a mid-sized city. When they touched, the collision briefly produced conditions denser and hotter than anywhere else in the observable universe.

ESO’s telescopes in Chile tracked the afterglow across a wide range of wavelengths, and the observatory’s October 2017 announcement of the first visible counterpart to a gravitational-wave source reported spectra suggesting caesium and tellurium in the ejecta. Two years later, a separate analysis of VLT X-shooter data pinned down strontium, the first individual heavy element identified in a neutron star collision. Some of the gold in a wedding ring was made in events like this one.

Why the remnant is a particle factory

Before they merge, neutron stars are cold by particle-physics standards — thermal energies around a kilo-electron-volt. The collision changes that within milliseconds. Temperatures in the remnant climb into the tens of MeV, and the benchmark merger profile Dev’s group used exceeds 50 MeV in places, roughly 600 billion degrees. Production rates for weakly coupled particles rise steeply with temperature. Whatever exists in the right mass window gets made.

Axion-like particles, or ALPs, are among the most-hunted candidates. They are cousins of the axion — the particle implied by the Peccei-Quinn mechanism proposed in 1977 to resolve a puzzle in the strong nuclear force, and named the following year by Weinberg and Wilczek. ALPs relax the axion’s strict relationship between mass and coupling, and they appear generically in string theory and in many extensions of the standard model.

The catch is that they interact with ordinary matter so feebly that laboratory experiments struggle to reach the parameter space that matters. Which is where dead stars come in.

How the bound actually works

The property Dev’s group targeted is the ALP’s coupling to photons. In the hot, dense matter of the remnant, two processes make ALPs: the Primakoff process, in which a photon scattering off a proton converts into an ALP, and photon coalescence, in which two photons merge into one. Primakoff dominates at low masses, coalescence at high ones, with the switchover around 100 MeV.

What happens next is the whole argument. ALPs stream out of the remnant — those with enough kinetic energy to climb out of its gravitational well, at least — and then decay back into pairs of photons well outside the debris. The team required decays beyond about 1,000 kilometres, far enough that the emitted photons would not simply be reabsorbed by the ejecta. The result would be a gamma-ray signal arriving roughly along the line of sight to the merger, offset in time from the gravitational waves by the geometry of where each ALP happened to decay.

Fermi-LAT was watching. It missed the prompt burst, but it collected data in the window from 1,153 to 2,027 seconds after the gravitational-wave signal, across 0.1 to 1 GeV, and saw nothing above a flux upper limit of 4.5 × 10⁻¹⁰ erg per square centimetre per second at 95% confidence. Every combination of ALP mass and photon coupling that would have produced a brighter signal than that is excluded. The preprint sets out the full calculation, including the decay geometry and the in-medium photon physics.

That is the first constraint of its kind derived from a merger, as the university’s announcement of the work noted. Two representative points in the newly excluded region sit at masses of 200 and 398 MeV. Worth being precise about what this is not: it is not a cooling argument. The team explicitly checked that across the parameter space they constrain, ALP emission does not drain enough energy to alter how the remnant cooled.

What the bound covers, and what it does not

The GW170817 exclusion is weaker than the long-standing limit from Supernova 1987A, and the reason is geometry rather than physics. Photon flux at Earth falls off with the square of the distance to the source. A supernova in the Large Magellanic Cloud is far closer than a merger at 40 megaparsecs, so it delivers more photons even from an identical ALP population.

What the merger offers instead is timing. The arrival of the gravitational-wave signal defines a clean zero point, which supernovae generally lack — for SN 2023ixf, no neutrino signal was detected at all. Combining spectral and temporal information from a merger, the authors argue, is where this method becomes competitive, particularly for observations inside the first second.

The constraint is also more robust than the article’s underlying uncertainties might suggest. GW170817’s remnant is thought to have survived about a second before collapsing to a black hole; varying that assumed lifetime between 0.72 and 1.29 seconds barely moves the exclusion region, and the result depends only weakly on which of nine merger profiles is used.

None of this detects anything. It tells you what an ALP cannot be, given that GW170817 behaved the way it did. And the dark matter question is separate again: an ALP in this mass range could in principle be a dark matter component, but a production bound from one merger says nothing about cosmological abundance. It shrinks the box. It does not confirm anything is in it.

The source that keeps giving

The merger’s own story has kept moving independently of the particle physics. Chandra saw nothing when it first slewed to the target, then found a point source on 26 August 2017. That sequence — non-detection, then detection — was itself the clue. It indicated a narrow relativistic jet pointed away from Earth, whose emission only reached the detector once the jet slowed and widened into the line of sight.

Then the fading stopped. As the Center for Astrophysics reported in March 2022, Aprajita Hajela of Northwestern University and colleagues found that from March 2020 through the end of that year the X-ray brightness held roughly constant. Something besides the jet had taken over. The two candidates are a kilonova afterglow — a shock from the expanding debris — or matter falling onto a newly formed black hole. Either would be a first, and radio observations are the test: a kilonova afterglow should brighten in radio, accretion onto a black hole should not.

At the time of that release, Chandra was the only observatory still able to detect the source, more than four years after the collision.

Space Daily has covered other corners of the same search. A Rice University team has used a grain-of-sand-sized magnet levitated above a superconductor to hunt for ultraheavy dark matter, extending the search toward candidates approaching the mass of a living cell, according to the group’s own account of the experiment. That is the far end of the mass axis from the MeV-scale ALPs Dev’s group is bounding — a table-top instrument at millikelvin temperatures on one side, a collision 130 million light-years away on the other.

Using distant catastrophes as instruments

GW170817 remains the only confirmed binary neutron star merger with a full electromagnetic counterpart. LIGO and Virgo have caught other candidate neutron star events, but none produced the same multi-wavelength bounty, which is why the same dataset keeps being reprocessed for new physics. A 2021 review by Milton Ruiz, Stuart Shapiro and Antonios Tsokaros in Frontiers in Astronomy and Space Sciences surveys what relativistic simulations can now say about these events, including the consensus that GW170817’s remnant lasted under a second before collapsing.

A cleaner ALP constraint needs more mergers, or closer ones. The authors sketch both: a stacked analysis of several events, a hypothetical merger ten times nearer, and early observation windows starting a tenth of a second after the gravitational-wave trigger. Proposed MeV gamma-ray missions such as AMEGO-X and e-ASTROGAM would help considerably.

When that data arrives is unsettled. O4 ended on 18 November 2025, and the detectors have since been in upgrades and commissioning. According to the LIGO-Virgo-KAGRA observing plan, an interim six-month run is expected around late 2026, while the timeline for the fifth observing run remains under discussion.

The hot phase of the merger lasted about one second. The gravitational-wave chirp lasted about a hundred. Somewhere between those two numbers is a photon signal that never reached Fermi’s detectors — and the precise shape of that absence, how bright it wasn’t and how early it wasn’t, is what now fences off a corner of parameter space where a particle nobody has ever seen can no longer hide.

The post Physicist Bhupal Dev at Washington University used the debris from GW170817 — the 2017 neutron star merger — to squeeze new limits on axion-like particles, treating the hot post-collision remnant as a natural forge for dark-matter candidates appeared first on Space Daily.

Black Arrow’s successful orbital flight arrived after its future had already been decided. On 28 October 1971, the British rocket launched Prospero from Woomera, Australia. Three months earlier, Parliament had been told that the programme would end once that mission was complete.

The next vehicle, R4, never launched. Its eventual place in the Science Museum gives the story a physical ending: one rocket carried a satellite into orbit, while its successor became an object through which later generations could examine the programme.

The final flight was explicitly allowed

The written parliamentary answer of 29 July 1971 is unusually clear. Responding to a question about the National Space Technology Programme, Frederick Corfield confirmed plans to launch the X3 satellite later that year. He then stated that Black Arrow would be terminated after the launch.

That matters because it distinguishes an authorised final mission from a launch carried out in defiance of cancellation. The decision and the permission appeared in the same answer. The engineers could complete the flight, but a successful result was not accompanied by a promise of further launches.

Corfield’s stated rationale concerned resources and capability. Maintaining a national launcher with comparatively limited capacity, he argued, consumed too much of the available programme while restricting its broader scope. The answer also said satellite technology research would continue, with X4 planned for a NASA Scout launch in 1974.

The launcher was ending; satellite work was continuing.

A British vehicle launched from Australia

ESA’s historical account confirms the date, the Woomera launch site and Prospero’s alternative designation, X3. Black Arrow’s development had begun in 1964 under the Royal Aircraft Establishment. Its achievement was the delivery of a satellite by a British-developed launcher, not a launch from British soil.

That distinction is easy to lose in a compressed account of national space achievements. The origin of a rocket, the origin of its payload and the territory from which it flies are separate facts. Here, the Australian desert was part of the infrastructure that made the British programme possible.

A UK Space Agency retrospective describes the wider effort behind the vehicle: rocket and engine development, assembly and test facilities in Britain, and launch and range facilities at Woomera. Black Arrow drew on earlier Royal Aircraft Establishment research and technologies using high-test peroxide and kerosene.

The agency describes a three-stage rocket about thirteen metres tall, with an eight-chamber engine in the first stage and a solid motor in the third. Those modest dimensions can obscure the range of systems required to produce an orbital flight. A launch vehicle is also a programme of testing, ground support, control and integration.

R4 records the launch that did not happen

The Science Museum Group’s collection record for Black Arrow R4 identifies it as the final vehicle built, with minor assembly and pipework incomplete. Its intended satellite, Miranda, eventually went into orbit on an American Scout rocket in 1974.

R4 is therefore more than a representation of the rocket that flew. It is surviving hardware from the next step that the programme did not take. Its parts preserve engineering decisions even though they never experienced a launch.

The museum records four Black Arrow launches, two successful, including the flight that orbited Prospero. That is a short development history, and it invites competing readings: a capability achieved just as support ended, or a limited programme whose costs had to be weighed against other space priorities.

The records establish the sequence without settling every argument about the decision. A successful flight demonstrates that a particular mission worked. It does not, on its own, calculate the costs, demand or reliability of an extended operational service. Equally, a decision to stop funding that service does not undo the technical achievement.

Becoming an exhibit required another decision

A Science Museum Group Journal study of R4 follows the vehicle’s transition into a museum object. It describes discussions soon after Prospero’s launch, when the departments responsible for Black Arrow were working towards winding up the programme by the end of March 1972.

Acquiring the rocket involved practical arrangements, not simply declaring it historic. The article records an estimated £5,000 to prepare it for transfer, to be met by the Department of Trade and Industry, with the museum responsible for transport from the Isle of Wight to its west London store.

The preservation of a cancelled project is itself work. Large objects need space, handling equipment and decisions about what to retain. Without those choices, the next rocket might have survived only in drawings and photographs.

R4 became evidence that people could stand beside.

Success and continuation were different questions

Black Arrow’s ending is often compelling because the chronology seems reversed: the programme was told to stop, then achieved its orbital goal. But the parliamentary statement shows that both outcomes had already been accommodated. The final flight could proceed while the longer-term launcher commitment ended.

Space Daily’s account of Project West Ford’s orbiting copper needles describes another space experiment whose technical demonstration did not lead to an enduring operational system. The reasons differed, but both histories reward separating what hardware proved from what institutions chose to continue.

Prospero’s launch and R4’s preservation mark those two questions in different places. One was answered above the Australian desert in October 1971. The other left a rocket on Earth, retaining the shape of a next flight that never came.

The post On 28 October 1971, a British Black Arrow rocket put Prospero into orbit from the Australian desert — Parliament had been told on 29 July that the programme would end after this flight, leaving the next rocket to become an unflown museum exhibit. appeared first on Space Daily.

A tube of pond scum on a Cambridge windowsill spent half a year running a computer, and nobody had to feed it.

The container held blue-green algae, water and very little else, and it was roughly the size of an AA battery. Inside it, a colony of microbes harvested light, leaked electrons into a strip of aluminium and produced a current steady enough to keep a microprocessor ticking over from February to August 2021. Smithsonian magazine reported that the whole apparatus sat out a pandemic lockdown on a windowsill in the home of Cambridge biochemist Paolo Bombelli.

It ran far longer than anyone on the project expected.

What was actually inside the container

Synechocystis is a cyanobacterium, one of the ordinary non-toxic pond dwellers that has been quietly photosynthesising for a couple of billion years. Photosynthesis splits water and sends the resulting electrons down an internal transport chain inside the cell. Some of that current leaks out before it is used, and a metal anode positioned nearby can catch it. Exactly how those electrons make the jump from a living cell to bare metal is still not settled.

Bombelli and his colleagues, writing in Energy & Environmental Science, described a small housing of clear plastic and steel with an aluminium anode inside, built from inexpensive and largely recyclable parts. No feeding, no charging. Cyanobacteria make their own food as they photosynthesise, so light and water cover the entire supply chain.

Stranger still, the current did not stop at sunset. Researchers on the team suspect the microbes carry on metabolising food banked earlier in the day, which is why the cell kept nudging out electricity through the dark hours, as the Cambridge Independent reported.

How little electricity this really is

Averaged across the experiment, the cell delivered about 1.05 microwatts at 0.72 volts, figures Gizmodo set against the obvious comparisons. A fresh AA battery starts life at 1.5 volts. An efficient LED globe pulls around 10 watts. So the device was generating something in the region of a ten-millionth of a globe.

That sufficed only because the chip had been picked for extreme frugality. An Arm Cortex M0+ can tick along on 0.3 microwatts, and Arm Research built the test chip, the board and the cloud link that logged everything the microbes did. Only the chip itself ran on that current. The cloud link, which reported the results back to the researchers, needed conventional power to do its job.

Devices of this kind hold one advantage over the better-known microbial fuel cell, which needs a steady diet of organic matter to keep its bacteria working. Researchers publishing in Nature Communications noted that biophotovoltaic systems skip that input altogether, since the cells feed themselves as they go. The fuel bill is nothing and the colony renews itself, roughly the combination a sensor buried in a paddock for a decade would want.

Why a microwatt earns a paper

Who needs a computer powered by pond water? Nobody, right now. The argument is about the enormous, boring category of devices that comes next: door sensors, soil monitors, tracking tags, all the small gadgets multiplying across the world. Forecasts in the same paper put the number of connected devices on a path towards a trillion by 2035, every one of them wanting its own portable trickle of electricity. Batteries go flat, and they depend on materials that are expensive and unpleasant to dig out of the ground.

Christopher Howe, the Cambridge biochemist who co-led the work, argued in the university’s announcement that supplying all that hardware will require systems that generate energy “rather than simply store it like batteries”.

What one windowsill proves

Six months of unbroken output went into the submitted paper, and the hardware simply carried on afterwards. The funders at the National Biofilms Innovation Centre later described the microprocessor as having run for a year and counting on nothing but ambient light and water.

A single device in a single house is a demonstration, and one paper is one paper.

Two things stand between this and anything resembling a product: a great deal more current, and some agreement on how to measure it. A review in Frontiers in Microbiology characterises biophotovoltaics as a field hobbled by very low current outputs and by experimental set-ups too inconsistent to compare with each other, which stalls any systematic push to improve them. No one has fully pinned down how electrons cross from a living cell into an electrode either, so progress tends to come from trying things and seeing what sticks.

Scaling up means manufacturing thousands of these cells cheaply and reliably, and doing it before anyone has fully worked out what is happening inside them.

The processor was disconnected a long time ago. By Bombelli’s account the algae carried on making electricity regardless, entirely indifferent to whether anything was still listening.

The post Cambridge researchers kept a computer chip running for a year using blue-green algae in a container about the size of an AA battery — the living power source harvested energy from light and continued supplying electricity through periods of darkness appeared first on Space Daily.

Thirteen viruses that have not circulated on Earth since before the last Ice Age’s coldest stretch are now, technically, alive again. A team led by Jean-Michel Claverie and Chantal Abergel at Aix-Marseille University, working with Russian colleagues from the Melnikov Permafrost Institute and other institutions, and German permafrost scientists from the Alfred Wegener Institute, pulled the samples from nine locations across Siberian and Kamchatkan permafrost and coaxed the ancient particles back into active replication in a lab dish. The oldest, a giant virus the team named Pandoravirus yedoma, came from sediment more than 16 meters beneath a thermokarst lake at Yukechi Alas in central Yakutia, radiocarbon-dated to over 48,500 years old. The strange part is not any of that. It’s that every single one of the thirteen, across five separate viral families, turned out capable of infecting exactly one thing: amoebae.

That is not a coincidence or a discovery about what these viruses are inherently limited to — it’s the result of a rule the researchers built into their methods before they ever opened a sample.

Nine sites, one very old lake bed, and a five-family haul

The study, published in the journal Viruses in February 2023, describes sampling seven ancient Siberian permafrost cores, a Lena River sediment sample, and one modern surface soil sample from Kamchatka as a comparison point. Out of that set, the team isolated 13 new viral strains spanning five clades: pandoraviruses, cedratviruses, megaviruses, pacmanviruses, and a new strain of pithovirus, the family first revived by the same lab back in 2014. Beyond the 48,500-year Pandoravirus yedoma strain, other samples dated to more than 27,000 and 28,600 years old, meaning the youngest viruses in the batch had still been dormant since well before agriculture existed anywhere on the planet.

Getting a virus that old to replicate again sounds harder than it is, mechanically. Permafrost is an unusually good preservative: constant sub-zero temperatures, no light, and low oxygen slow decay to something close to a standstill. The genuine difficulty was deciding what, exactly, the revived particles should be allowed to infect — not reviving them in the first place.

Why the answer was decided in advance

Every one of the 13 viruses was isolated using a single host organism: Acanthamoeba castellanii, a free-living amoeba common in soil and freshwater that happens to be an excellent, and epidemiologically inert, lab culture system for giant viruses. The paper’s own framing makes clear this was the point, not an accident: as the authors put it, the viruses recovered “belong to five different clades infecting Acanthamoeba spp.” precisely because of “the host specificity imposed by our protocol.” In plain terms, the team only exposed each sample to amoeba cultures, so the only viruses that could be detected at all were ones already capable of infecting amoebae. Anything in the sediment that might have targeted a mammal, a bird, or a human cell simply had no host present to reveal itself.

Claverie has been explicit about why that constraint exists. “Our protocol is to put amoeba cultures in the lab in contact with various samples, in the hope that they will contain viruses capable of infecting amoebas,” he told Live Science, adding a flatter, more direct version of the same point: “We will never risk isolating a virus eventually capable of infecting modern mammals.” The paper itself makes the comparison explicit, noting that the biohazard from reviving amoeba-only viruses is “totally negligible” next to the far riskier work of hunting for pathogens directly inside the frozen remains of mammoths and other ancient mammals, which is why that specific line of research is confined to a biosafety level 4 facility in Novosibirsk rather than an ordinary university lab.

Every choice the team made before opening a single sample was a choice about what they were willing to risk being wrong about.

The part that actually worries the researchers

That caution isn’t really about this batch of 13 viruses. It’s about what else permafrost is holding, and how much more of it is on its way to thawing. Claverie has made this argument before: back in late 2022, months before Pandoravirus yedoma’s record-setting age was even published, he told Newsweek, “If amoeba viruses can survive in these conditions, there is no reason for other viruses not to survive as well” — the same underlying logic the yedoma finding would go on to reinforce.

The paper’s own conclusion frames the risk in terms of exposure rather than certainty: nobody can currently estimate how long a thawed ancient virus would stay infectious once it hit open air, or how likely it would be to encounter a suitable host in that window. What has changed, and what makes the question worth asking at all, is the denominator. Arctic permafrost is thawing faster as the region warms, and industrial development, mining, and new settlements are sending more people into exactly the areas where 48,500-year-old ground is being exposed for the first time since before modern humans reached most of the planet. The amoebae were never really the point. They were the deliberately narrow lens the researchers chose so that the first question, can something this old still replicate at all, could be answered without opening a second, much harder question before anyone was ready to.

The post French, Russian, and German researchers thawed sediment from nine sites of Siberian and Kamchatkan permafrost and revived thirteen previously undescribed viruses, the oldest of them from ground beneath a Yakutian lake bed dated to more than 48,500 years, and the reason every one of the thirteen can infect nothing but amoebae is a decision the team made before the first sample went into the dish appeared first on Space Daily.