NASA has formally commented on a request by a US company to build a mega-constellation of satellites at an altitude of 720km above the Earth's surface, citing concerns about collisions. From a report: This appears to be the first time that NASA has publicly commented on such an application for market access, which is pending before the Federal Communications Commission. "NASA submits this letter during the public comment period for the purpose of providing a better understanding of NASA's concerns with respect to its assets on-orbit, to further mitigate the risks of collisions for the mutual benefit of all involved," wrote Samantha Fonder, an engineer for the space agency. At issue are plans put forth by AST & Science, which intends to build a constellation of more than 240 large satellites, essentially deploying "cell towers" in space to provide 4G and possibly 5G broadband connection directly to cell phones on Earth. The company, based in Midland, Texas, calls its constellation "SpaceMobile" and has raised an estimated $120 million.

An anonymous reader quotes a report from ZDNet: [E]ven today's most sophisticated GPS systems are still unable to map a huge chunk of the Earth: that which is located under oceans, seas, or rivers. The technology, in effect, doesn't mix well with water, which breaks down the radio waves GPS relies on to function. MIT scientists have been looking at ways to create a new type of underwater GPS, which could be used to better understand the mysteries that lie between surface and seabed. The researchers have now unveiled a device called an underwater backscatter localization (UBL) that reacts to acoustic signals to provide positioning information, even when it is stuck in oceanic depths. All of this, without even using a battery.

Underwater devices already exist, for example to be fitted on whales as trackers, but they typically act as sound emitters. The acoustic signals produced are intercepted by a receiver that in turn can figure out the origin of the sound. Such devices require batteries to function, which means that they need to be replaced regularly -- and when it is a migrating whale wearing the tracker, that is no simple task. On the other hand, the UBL system developed by MIT's team reflects signals, rather than emits them. The technology builds on so-called piezoelectric materials, which produce a small electrical charge in response to vibrations. This electrical charge can be used by the device to reflect the vibration back to the direction from which it came. In the researchers' system, therefore, a transmitter sends sound waves through water towards a piezoelectric sensor. The acoustic signals, when they hit the device, trigger the material to store an electrical charge, which is then used to reflect a wave back to a receiver. Based on how long it takes for the sound wave to reflect off the sensor and return, the receiver can calculate the distance to the UBL.

In practice, piezoelectric materials are no easy component to work with: for example, the time it takes for a piezoelectric sensor to wake up and reflect a sound signal is random. To solve this problem, the scientists developed a method called frequency hopping, which involves sending sound signals towards the UBL system across a range of frequencies. Because each frequency has a different wavelength, the reflected sound waves return at different phases. Using a mathematical theorem called an inverse Fourier transform, the researchers can use the phase patterns and timing data to reconstruct the distance to the tracking device with greater accuracy. Frequency hopping showed some promising results in deep-sea environments, but shallow waters proved even more problematic. Because of the short distance between surface and seabed, sound signals uncontrollably bounce back and forth in lower depths, as if in an echo chamber, before they reach the receiver -- potentially messing with other reflected sound waves in the process. [...] While the scientists acknowledged that addressing these challenges would require further research, a proof-of-concept for the technology has already been tested in shallow waters, and MIT's team said that the UBL system achieved centimeter-level accuracy.

Scientists from MIT have developed a new AI model that can detect COVID-19 from a simple forced cough. ScienceAlert reports: Evidence shows that the AI can spot differences in coughing that can't be heard with the human ear, and if the detection system can be incorporated into a device like a smartphone, the research team thinks it could become a useful early screening tool. The work builds on research that was already happening into Alzheimer's detection through coughing and talking. Once the pandemic started to spread, the team turned its attention to COVID-19 instead, tapping into what had already been learned about how disease can cause very small changes to speech and the other noises we make.

The Alzheimer's research repurposed for COVID-19 involved a neural network known as ResNet50. It was trained on a thousand hours of human speech, then on a dataset of words spoken in different emotional states, and then on a database of coughs to spot changes in lung and respiratory performance. When the three models were combined, a layer of noise was used to filter out stronger coughs from weaker ones. Across around 2,500 captured cough recordings of people confirmed to have COVID-19, the AI correctly identified 97.1 percent of them -- and 100 percent of the asymptomatic cases.

That's an impressive result, but there's more work to do yet. The researchers emphasize that its main value lies in spotting the difference between healthy coughs and unhealthy coughs in asymptomatic people -- not in actually diagnosing COVID-19, which a proper test would be required for. In other words, it's an early warning system. The researchers now want to test the engine on a more diverse set of data, and see if there are other factors involved in reaching such an impressively high detection rate. If it does make it to the phone app stage, there are obviously going to be privacy implications too, as few of us will want our devices constantly listening out for signs of ill health. The research has been published in the IEEE Open Journal of Engineering in Medicine and Biology.

Oregonians have voted to pass Measure 109 to become the first state in the country to legalize psilocybin. OregonLive reports: Measure 109 was passing by 59.25% Tuesday when the polls closed in Oregon. Multiple cities have decriminalized the substance, but Oregon will become the first to permit supervised use statewide if that majority holds. The measure [...] will allow regulated use of psychedelic mushrooms in a therapeutic setting.

It creates a two-year period during which regulatory details will be worked out, including what qualifications are required of therapists overseeing its use. [P]silocybin could help people struggling with issues from depression to anxiety to addiction. The new law will allow anyone age 21 or older who passes a screening to access the services for "personal development." But the law won't mean that "magic" mushrooms have the same legal status as cannabis. Instead, it will allow psilocybin to be stored and administered at licensed facilities. Oregonians also voted to pass Measure 110, which will decriminalize possession of small amounts of drugs, including psychedelic mushrooms.

Here's a good sign for alien hunters: More than 300 million worlds with similar conditions to Earth are scattered throughout the Milky Way galaxy. A new analysis [PDF] concludes that roughly half of the galaxy's sunlike stars host rocky worlds in habitable zones where liquid water could pool or flow over the planets' surfaces. From a report: "This is the science result we've all been waiting for," says Natalie Batalha, an astronomer with the University of California, Santa Cruz, who worked on the new study. The finding, which has been accepted for publication in the Astronomical Journal, pins down a crucial number in the Drake Equation. Devised by my father Frank Drake in 1961, the equation sets up a framework for calculating the number of detectable civilizations in the Milky Way. Now the first few variables in the formula -- including the rate of sunlike star formation, the fraction of those stars with planets, and the number of habitable worlds per stellar system -- are known. The number of sunlike stars with worlds similar to Earth "could have been one in a thousand, or one in a million -- nobody really knew," says Seth Shostak, an astronomer at the Search for Extraterrestrial Intelligence (SETI) Institute who was not involved with the new study.

Astronomers estimated the number of these planets using data from NASA's planet-hunting Kepler spacecraft. For nine years, Kepler stared at the stars and watched for the brief twinkles produced when orbiting planets blot out a portion of their star's light. By the end of its mission in 2018, Kepler had spotted some 2,800 exoplanets -- many of them nothing like the worlds orbiting our sun. But Kepler's primary goal was always to determine how common planets like Earth are. The calculation required help from the European Space Agency's Gaia spacecraft, which monitors stars across the galaxy. With Gaia's observations in hand, scientists were finally able to determine that the Milky Way is populated by hundreds of millions of Earth-size planets orbiting sunlike stars -- and that the nearest one is probably within 20 light-years of the solar system.

An anonymous reader shares a report: The Voyager 2 probe, one of NASA's most well-traveled spacecraft, has been unable to communicate with Earth for the past eight months. Voyager 2 has been wandering alone at the edge of interstellar space, gathering data some 11.6 billion miles from Earth and sending it back to us. But we haven't been able to pick up the phone and call back. The only radio antenna that can communicate with the probe, Deep Space Station 43 (DSS43) in Australia, has been offline while NASA completes a series of hardware upgrades. Some of the transmitters on DSS43 haven't been replaced for over 47 years, according to NASA. To test new hardware, the dish pinged Voyager 2 on Oct. 29 with a few commands. It was the first time since mid-March that a signal was beamed to the spacecraft. And because the probe is so far away, the communication team had to wait over 34 hours for a reply. Sure enough, Voyager 2 received the commands with no problems and sent back a "hello."

The COVID-19 exposure notification app used in England and Wales failed to warn users if they were in close contact with potentially infectious COVID-19 patients. Because of the error, thousands of people were not told to quarantine even when they should have been, according to the Sunday Times, which first reported the flaw. The Verge reports: The app was launched on September 24th, and there have been 19 million downloads since. It's built using Google and Apple's Bluetooth Low Energy-based system, which monitors nearby phones. If someone tests positive for COVID-19, their app can alert the phones that they were in contact with. The UK originally planned to use its own app, sidestepping the Google and Apple system, but reversed course in June. Since its launch, the app flagged few users for possible exposure, according to the Sunday Times. Engineers figured out the reason why last week. The app was originally built to simply recommend that anyone closer than 2 meters for more than 15 minutes to someone who later tested positive should quarantine, according to The Guardian. But just before the launch, it was adjusted to take into account when the sick person's symptoms began.

Research shows that people tend to have high levels of virus in their nose and throat, and may be more contagious, around a day before they start to show symptoms. Levels stay high the first few days of symptoms, and then drop off. If someone was in contact with a sick person outside of that window, the UK app would consider the interaction less risky. If they were in contact inside of that window, on the other hand, it would only take three minutes of contact to trigger an alert. The adjusted app did calculate those new risk levels. But the thresholds at which a person would actually get an alert were left unchanged, according to a government blog post. Without the updated thresholds, a user could have spent up to 15 minutes with a highly infectious person and up to 40 minutes with a less-contagious person without getting an alert, according to The Guardian.

Scientists are tracking small differences in DNA to explain why the disease has different effects. An anonymous reader shares a report from The Guardian: Key developments include research which indicates that interferon -- a molecular messenger that stimulates immune defenses against invading viruses -- may play a vital role in defending the body. Scientists have found that rare mutations in some people may leave them unable to make adequate supplies of the interferon they need to trigger effective immune responses to Covid. Trials using interferon as Covid treatments are now under way at several centers. Research is also focusing on a gene known as TYK2. Some variants of this gene are involved in triggering some auto-immune diseases such as rheumatoid arthritis (RA) and also seems to be involved in causing severe Covid. A drug developed to treat RA, baricitinib, has a genetic common denominator with Covid and this has led to it being used in clinical trails against the virus. Last month the pharmaceutical company Eli Lilly announced that early results showed the drug helped Covid patients recover.

Other research -- pioneered by Kenneth Baillie, of Edinburgh University, and outlined in a recent issue of Science -- has uncovered several other genes that appear to be important. These include OAS genes that are triggered by interferon and which code for proteins that are involved in breaking down viral RNA, from which the Covid-19 virus is made. Baillie's research has yet to be peer reviewed and he has counseled caution in interpreting this work. Nevertheless, he told Science that he hoped his results would speed the development of treatments "because the epidemic is progressing at such an alarming rate, even a few months of time saved will save lots of lives".

In addition, other researchers point out that there are other ways of using genetics to combat Covid. Dr Dipender Gill of Imperial College London has, with colleagues, used genetic data to predict how different interventions could affect disease reactions. To do that, Gill -- working with a team of British, Norwegian and American scientists -- analyzed data from thousands of patients, using genetic variants that increase individuals' risk of acquiring these conditions. They were then able to carry out studies that would show if action taken to modify these traits would reduce susceptibility to severe Covid-19. The team made two key discoveries. "We found there is a causal link between obesity and the risk of having a severe Covid-19 [reaction]. We also found the same effect for smoking. This indicates that losing weight and giving up smoking will have a direct impact in improving your chances of surviving Covid-19. That is the power of genetic studies like these."

GPS isn't waterproof. The navigation system depends on radio waves, which break down rapidly in liquids, including seawater. To track undersea objects like drones or whales, researchers rely on acoustic signaling. But devices that generate and send sound usually require batteries -- bulky, short-lived batteries that need regular changing. Could we do without them? From a report: MIT researchers think so. They've built a battery-free pinpointing system dubbed Underwater Backscatter Localization (UBL). Rather than emitting its own acoustic signals, UBL reflects modulated signals from its environment. That provides researchers with positioning information, at net-zero energy. Though the technology is still developing, UBL could someday become a key tool for marine conservationists, climate scientists, and the U.S. Navy. These advances are described in a paper being presented this week at the Association for Computing Machinery's Hot Topics in Networks workshop, by members of the Media Lab's Signal Kinetics group.

Government researchers have confirmed that the steep decline in air traffic during the coronavirus pandemic has affected the quality of weather forecasting models by sharply reducing the amount of atmospheric data routinely collected by commercial airliners. From a report: In a study, researchers showed that when a short-term forecasting model received less data on temperature, wind and humidity from aircraft, the forecast skill (the difference between predicted meteorological conditions and what actually occurred) was worse. The researchers and others had suspected this would be the case because atmospheric observations from passenger and cargo flights are among the most important data used in forecasting models. The observations are made by instruments aboard thousands of airliners, mostly based in North America and Europe, as part of a program in place for decades. They are transmitted in real time to forecasting organizations around the world, including the National Weather Service. During the first months of the pandemic, when air traffic declined by 75 percent or more worldwide, the number of observations dropped by about the same percentage.

"With every kind of observation that goes into weather models, we know they have some impact on improving accuracy overall," said one of the researchers, Stan Benjamin, a senior scientist at the Global Systems Laboratory, a part of the National Oceanic and Atmospheric Administration, in Boulder, Colo. "If you've really lost a lot of observations of some kind there could be some stepping back in skill overall." While the researchers showed that the data loss contributed to making the model less accurate, NOAA said that so far it had not seen an impact on the type of short-term forecasts that companies use to make business decisions or a person might use to decide if they need to take an umbrella when going out.

The continent of Australia, where nearly 25 million people live, "has recorded its first day of no local cases of Covid-19 in almost five months," reports the BBC: Zero cases were reported in the 24 hours between 20:00 on Friday and 20:00 on Saturday - the first time this has happened since 9 June. The state of Victoria - epicentre of Australia's second wave - recorded zero cases for the second day in a row after a 112-day lockdown.

Health officials say more restrictions may be eased in the coming days. "Thank you to all of our amazing health & public health workers & above all else the Australian people," Health Minister Greg Hunt said on his Twitter account.
Australia combined lockdowns with "proactive testing and tracing," the article reports, adding that in addition Victoria "imposed some of the severest stay-at-home and curfew rules in the world."

The BBC reports: Slovakia has begun an ambitious project to test everyone over the age of 10 for Covid-19, but the president has said she thinks the idea is "unfeasible".

The operation to test four million people is to last over two weekends. Infections have soared in Slovakia and officials argue the only alternative would be a total lockdown. President Zuzana Caputova called for a rethink of the plan after armed forces chiefs said there were not enough trained health workers to carry it out. So far only 70% of the 20,000 staff needed to administer the nasal swab tests have been recruited, according to the defence minister...

From dawn on Saturday, soldiers and medics were due to fan out across the country, from the vast Petrzalka housing estates of Bratislava, to tiny hamlets in the shadows of the Tatra Mountains, to the mostly Hungarian-speaking towns dotted along the Danube plain.... The plan is to test almost four-fifths of the population, using rapid antigen testing that has an estimated 30% false negative rate. Results will be delivered in a sealed envelope within 30 minutes. "It's the army's biggest logistical operation since the country became independent," said Defence Minister Jaro Nad...

Slovakia's numbers are far lower but government modelling predicts a catastrophic overload of hospitals by mid-November if nothing is done. "There's no alternative — it's either mass testing or harsh lockdown," Mr Nad told the BBC.... While testing is voluntary, those who refuse must self-isolate for 10 days. Breaking that quarantine will be punished with a hefty fine. A negative test result, however, will serve as a "free pass" from a curfew due to be introduced from Monday...

If it works, other countries might soon follow suit.

NASA's 322-foot rocket "Space Launch System" rocket "would be the most powerful rocket ever flown, eclipsing both the Saturn V that flew astronauts to the moon and SpaceX's Falcon Heavy," reports the Washington Post.

But "it's not the rocket's engines that concern officials but the software that will control everything the rocket does, from setting its trajectory to opening individual valves to open and close." Computing power has become as critical to rockets as the brute force that lifts them out of Earth's atmosphere, especially rockets like the SLS, which is really an amalgamation of parts built by a variety of manufacturers: Boeing builds the rocket's "core stage," the main part of the vehicle. Lockheed Martin builds the Orion spacecraft. Aerojet Rocketdyne and Northrop Grumman are responsible for the RS-25 engines and the side boosters, respectively. And the United Launch Alliance handles the upper stage. All of those components need to work together for a mission to be successful. But NASA's Aerospace Safety Advisory Panel recently said it was concerned about the disjointed way the complicated system was being developed and tested...

Also troubling to the safety panel was that NASA and its contractors appeared not to have taken "advantage of the lessons learned" from the botched flight last year of Boeing's Starliner spacecraft, which suffered a pair of software errors that prevented it from docking with the International Space Station as planned and forced controllers to cut the mission short. NASA has since said that it did a poor job of overseeing Boeing on the Starliner program, and has since vowed to have more rigorous reviews of its work, especially its software testing...

NASA pushed back on the safety panel's findings, saying in a statement that "all software, hardware, and combination for every phase of the Artemis I mission is thoroughly tested and evaluated to ensure that it meets NASA's strict safety requirements and is fully qualified for human spaceflight." The agency and its contractors are "conducting integrated end-to-end testing for the software, hardware, avionics and integrated systems needed to fly Artemis missions," it said.

"The Linux Foundation has formed a new group to provide public health authorities with free technology for tracking the spread of the coronavirus and future epidemics," writes Business Insider. Launched in July, the group has already released two apps "that notify users if they've been in contact with someone who has tested positive with COVID-19." Since these apps are open source, people can contribute code and customize them, allowing regions with similar needs to collaborate, general manager at Linux Foundation Public Health, Dan Kohn, told Business Insider. Developers that want to build an app off these projects can access or download the source code.

These apps take advantage of technology launched by Apple and Google, which can be integrated into any app, that uses Bluetooth on people's smartphones to track who a user has been in close proximity with, without identifying the specific people. If anyone tests positive for COVID-19 and uploads that information to a database run by a local public health authority, any user who has been in close contact with that person will get a notification through their app saying they may have been exposed — again, without identifying who has COVID-19. If someone knows that they may have been exposed, they can either self-quarantine or get tested.

"Essentially we think exposure notification could have a big impact on reducing the overall rate of exposure," Kohn said. An Oxford University study in April said that if about 60% of the population used a contact tracing app, it could grind the diseases spread to a halt. Researchers on the team also found that digital contact tracing can cut down spread even at much lower levels of usage.

On October 2, SpaceX automatically aborted the launch of a Falcon 9 rocket (with just two seconds left in the countdown) after two of its first-stage engines ignited early. Investigating the problem ended up delaying the October 31st launch of four astronauts to the International Space Station until November 14, reports Ars Technica, citing a teleconference with SpaceX's Hans Koenigsmann.

"Had the abort not triggered, it is likely that nothing bad would have occurred, but Koenigsmann said that under certain extreme scenarios, rattling from an early ignition may cause significant damage to the Merlin engines." SpaceX technicians removed the two engines and shipped them from Florida to the company's test site in McGregor, Texas, where they were able to replicate the problem. They found that a relief valve within the gas generator — a tiny rocket within the engine that starts up and powers its machinery — was clogged with a masking lacquer akin to nail polish. They were able to show that removing the lacquer from the vent hole allowed the engines to start up normally. This lacquer is applied during an anodizing process to treat aluminum components of the gas generator. It is supposed to be subsequently removed, but in the case of these two engines, a tiny amount of the material had been trapped within a bore hole less than 2mm across...

After this, SpaceX inspected other engines across its fleet (the company inspected new boosters only, as Falcon 9 first stages that have already flown are not subject to this issue). SpaceX found that two of the engines on the Falcon 9 rocket that will be used for the Crew-1 launch also had this problem. Those two engines are now being swapped out for new Merlins...

This lacquer issue came as a surprise given that SpaceX has literally launched hundreds of new Merlin 1D rocket engines over the last decade and, until now, had not seen this problem with the masking agent. "It's certainly possible that we had cases of it earlier, and they were appreciably so harmless that we completely missed them," Koenigsmann said. It is also possible that a small process was changed so that all of the lacquer was not removed, as this particular treatment is done by an outside vendor. But, he admitted, "It's difficult to explain how this works for so many years and then, suddenly, you see this coming up in the data."

What Koenigsmann seems confident in is that the issue will not occur again.

This week Moderna "said it is on track to report early data from a late-stage trial of its experimental COVID-19 vaccine next month, reports Reuters, "offering the clearest timeline yet for when the world will know whether it is effective." The company, one of the front-runners in the global race to produce vaccines to protect against COVID-19, said an independent data monitoring committee is expected to conduct an interim review of its ongoing 30,000-person trial in November... The company said it is preparing to distribute the vaccine, known as mRNA-1273, and expects to be able to produce 20 million doses by the end of the year, and between 500 million and 1 billion in 2021. Moderna said infection rates in the trial were on track with expectations...

Moderna said it expects two-month follow-up safety data, as required by the U.S. Food and Drug Administration, in the second half of November, after which it will file for an emergency use authorization.

CNN reports: Saturn's largest moon, Titan, is the only moon in our solar system that has a thick atmosphere. It's four times denser than Earth's. And now, scientists have discovered a molecule in it that has never been found in any other atmosphere.

The particle is called cyclopropenylidene, or C3H2, and it's made of carbon and hydrogen. This simple carbon-based molecule could be a precursor that contributes to chemical reactions that may create complex compounds.

And those compounds could be the basis for potential life on Titan.

The molecule was first noticed as researchers used the Atacama Large Millimeter/submillimeter Array of telescopes in Chile. This radio telescope observatory captures a range of light signatures, which revealed the molecule among the unique chemistry of Titan's atmosphere. The study published earlier this month in the Astronomical Journal...

"We're trying to figure out if Titan is habitable," said Rosaly Lopes, a senior research scientist and Titan expert at JPL, in a statement. "So we want to know what compounds from the atmosphere get to the surface, and then, whether that material can get through the ice crust to the ocean below, because we think the ocean is where the habitable conditions are."

Europe "now accounts for 46% of global coronavirus cases," reports ABC News, "and nearly a third of total related deaths." Dr. Jean-Francois Delfraissy, a senior French physician and the president of the scientific council that reports to the government, warned that the country has "lost control of the epidemic," after health authorities reported more than 52,000 new cases. He said that the council estimates that the true figure could well be closer to 100,000 daily cases, accounting for asymptomatic cases and those who haven't been tested...

Fearing both the economic price of national lockdowns and the political backlash from citizens increasingly wearied of the restrictions on their livelihoods, government officials around Europe have been reluctant to shutter businesses to the extent that they did in the spring.
The Guardian reports that Apple "will temporarily close 17 of its 20 stores in France from Oct. 30, as the country goes into a fresh one-month lockdown due to a resurgence of coronavirus cases."

Meanwhile, CNN reports that Taiwan "just marked its 200th consecutive day without a locally transmitted case of the disease," due partly to mass testing but also quick and effective contact tracing. Taiwan's landmark achievement comes in a week when France and Germany are enacting new lockdowns and the United States identified a record 88,000-plus cases in a day. The state of Florida, which has a similar population size to Taiwan, with approximately 21 million people, identified 4,188 cases on Wednesday alone.

schwit1 writes: SpaceX will not recognize international law on Mars, according to the Terms of Service of its Starlink internet project. Elon Musk's space company will instead reportedly adhere to a set of "self-governing principles" that will be defined at the time of Martian settlement. Musk revealed plans to create a self-sustaining city on Mars last week, though no timeframe is yet to be put in place for its development. Any future colony created by SpaceX would likely use constellations of Starlink satellites orbiting the planet to provide internet connection to people and machines on the surface.

"For services provided on Mars, or in transit to Mars via Starship or other colonization spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities," the governing law section states. "Accordingly, disputes will be settled through self-governing principles, established in good faith, at the time of Martian settlement." Space systems engineer Erwan Beauvois said SpaceX's position was reminiscent of a declaration put forward by the Earthlight Foundation, a non-profit organization committed to preparing for the expansion of humanity beyond Earth. The Declaration of the Rights and Responsibilities of Humanity in the Universe states that space should be "considered free, by all, for all and to all."

An anonymous reader quotes a report from The Guardian: The U.S. and UK produce more plastic waste per person than any other major countries, according to new research. The analysis also shows the U.S. produces the most plastic waste in total and that its citizens may rank as high as third in the world in contributing to plastic pollution in the oceans. Previous work had suggested Asian countries dominated marine plastic pollution and placed the U.S. in 20th place, but this did not account for U.S. waste exports or illegal dumping within the country. Data from 2016, the latest available, show that more than half of the plastic collected for recycling in the U.S. was shipped abroad, mostly to countries already struggling to manage plastic waste effectively. The researchers said years of exporting had masked the U.S.'s enormous contribution to plastic pollution.

The latest study, published in the journal Science Advances, used World Bank data on waste generation in 217 countries. It focused on the U.S. and used additional data on littering and illegal dumping within the country and on contamination by exported plastic, which is likely to be dumped rather than recycled. The researchers found the U.S. produced the most plastic waste by World Bank reckoning, at 34m tonnes in 2016, but the total increased to 42m tonnes when the additional data was considered. India and China were second and third, but their large populations meant their figures for per capita plastic waste was less than 20% of that of U.S. consumers. Among the 20 nations with the highest total plastic waste production, the UK was second to the U.S. per capita, followed by South Korea and Germany. "When the researchers estimated how much of each country's plastic waste ends up in the oceans, Indonesia and India ranked highest," the report adds. "The U.S. ranked between third and eleventh, depending on the assumptions made about waste leakage into the environment. The analysis found that up to 1 million tons of exported U.S. plastic waste ended up as marine pollution."