sciencehabit shares a report from Science Magazine: Researchers have found that when everything from icebergs to rocks breaks apart, their pieces tend to resemble cubes. The finding suggests a universal rule of fragmentation at scales ranging from the microscopic to the planetary. The scientists started their study "fragmenting" an abstract cube in a computer simulation by slicing it with 50 two-dimensional planes inserted at random angles. The planes cut the cube into 600,000 fragments, which were, on average, cubic themselves -- meaning that, on average, the fragments had six sides that were quadrangles, although any individual fragment need not be a cube. The result led the researchers to suspect that cubes might be a common feature of fragmentation.

The researchers tried to confirm this hunch using real-world measurements. They headed to an outcrop of the mineral dolomite on the mountain Harmashatarhegy in Budapest, Hungary, and counted the number of vertices in cracks in the stone face. Most of these cracks formed squarish shapes, which is one of the faces of a cube, regardless of if they had been weathered naturally or had been created by humans dynamiting the mountain. Finally, the team created more-powerful supercomputer simulations modeling the breakup of 3D materials under idealized conditions -- like a rock being pulled equally in all directions. Such cases formed polyhedral pieces that were, in an average sense, cubes. The researchers reported their findings in Proceedings of the National Academy of Sciences.

A tiny piece of Martian basalt the size of a 10p coin will be launched on board a U.S. robot probe on Thursday and propelled towards the red planet on a seven-month journey to its home world. The Guardian reports: This extraordinary odyssey, the interplanetary equivalent of sending coals to Newcastle, will form a key part of Nasa's forthcoming Mars 2020 expedition. Space engineers say the rock -- which has been donated by the Natural History Museum in London -- will be used to calibrate detectors on board the robot rover Perseverance after it lands and begins its search for signs of past life on the planet. "When you turn on instruments and begin to tune them up before using them for research, you calibrate them on materials that are going to be like the unknown substances you are about to study. So what better for studying rocks on Mars than a lump that originated there?" said Professor Caroline Smith, the Natural History Museum's principal curator of meteorites.

Scientists were confident that the rock they were returning to Mars originated on the planet, added Smith, who is also a member of the Mars 2020 science team. "Tiny bubbles of gas trapped inside that meteorite have exactly the same composition as the atmosphere of Mars, so we know our rock came from there." It is thought that the Martian meteorite was created when an asteroid or comet plunged into the planet about 600,000 to 700,000 years ago, spraying debris into space. One of those pieces of rubble swept across the solar system and eventually crashed on to Earth. That meteorite -- now known as SAU 008 -- was discovered in Oman in 1999 and has been in the care of the Natural History Museum since then.

Among the instruments fitted to the Perseverance rover is a high-precision laser called Sherloc, which will be used to decipher the chemical composition of rocks and determine if they might contain organic materials that indicate life once existed -- or still exists -- on Mars. The inclusion of a piece of SAU 008 is intended to ensure this is done with maximum accuracy. Once Perseverance has selected the most promising rocks it can find, it will dump them in caches on the Martian surface. These will then be retrieved by subsequent robot missions and blasted into space towards Earth for analysis.

The desert locust upsurge is yet another of 2020's horrors. From a report: In June, remote sensing analyst Raj Bhagat noticed a strange signal on India's weather radar. It looked like a small band of rain near Delhi, moving southwest, but Bhagat was convinced it was a locust swarm. "People began to report it," he says, referring to sightings on the ground. Giant locust swarms had spread to northern India earlier in the year, ravaging crops and destroying people's livelihoods. "The timelines were perfectly matching." In mid-July, Bhagat, who works at the World Resources Institute India, identified a similar formation, this time near the city of Lucknow. He posted it to Twitter with the hashtag #LocustsAttack. The desert locust upsurge is yet another of 2020's horrors. In dry years, the insects, which can grow up to four inches long and are shades of green, black, or yellow depending on their life stage, remain localized to the deserts of Africa, the Middle East, and southwest Asia. Lately, however, the weather has been wetter than usual. Desert locusts have bred prolifically and migrated in huge swarms to countries that don't always see them in large numbers, including several nations along the horn of Africa. Other places, such as the state of Uttar Pradesh in India, haven't had a locust invasion in decades.

The locust outbreak is currently classed by the United Nations Food and Agricultural Organization (FAO) as an "upsurge." If the insects begin migrating in large bands -- which could happen within a couple years, should things worsen -- they'll be officially considered a plague. A swarm covering one square kilometer eats as much food as 35,000 people every day. The damage done so far is already appalling. The UN says the food supply of 25 million people in East Africa has been threatened by the insects. In Ethiopia alone, they've destroyed around 200,000 hectares of crops. Meanwhile, in India, the insects have chewed up 50,000 hectares. The recent outbreak may be just a hint of what is to come, thanks to the extreme weather expected as a result of climate change. Such conditions, including periods of excessive rainfall, would be adored by the locusts, says Keith Cressman, senior locust forecasting officer at the FAO. The locusts' wanderlust has sparked efforts to develop tools to closely track the insects. The FAO already uses real-time reports from locust survey teams on the ground and satellite imagery of vegetation and weather events to help forecast how many locusts will breed and where they will go.

Countries use data on locust migrations to determine where to send teams in efforts vanquish the insects en masse by dropping pesticide on them from planes. Among the technologies that could improve locust surveillance by pinpointing locations of multiple swarms at a given moment are radar and drones. The idea of using remote sensing technologies like radar to spy on locust swarms is not new. A 1955 letter in the journal Nature reported the first such sighting on British naval radar the previous year. HMS Wild Goose had detected a humongous 48-kilometer-wide swarm of desert locusts flying over the Persian Gulf. Bhagat says he thinks his sightings are the first weather radar detections of locusts in India, though his observations haven't been confirmed yet. Ryan Neely III, an atmospheric scientist at the University of Leeds in the U.K., is building a specialized system to do the same kind of analysis. It is absolutely possible to use weather radar to spot the insects, he says. They are, after all, not that dissimilar from large raindrops.

Scientists are conducting preliminary tests of COVID-19 drugs using 3D printed human organs, eliminating the need to perform tests on animals, or, of course, humans. The Week reports: For example, Anthony Atala, the director of the Wake Forest Institute for Regenerative Medicine, and his team are using 3-D printers to create tiny replicas of human organs, including miniature lungs and colons, which are particularly affected by the coronavirus. They send them overnight for testing at a biosafety lab at George Mason University. The idea predated the coronavirus -- Atala said he never thought "we'd be considering this for a pandemic" -- but it could come in handy and help expedite the experimental drug process, especially since Atala said his Winston-Salem, North Carolina-based lab can churn out thousands of printed organs per hour. "The 3-D models can circumvent animal testing and make the pathway stronger from the lab to the clinic," said Akhilesh Gaharwar, who directs a lab in the biomedical engineering at Texas A&M University. Further reading: The New York Times

In a report published today by the National Institutes of Science and Technology (NIST), a physical sciences laboratory and non-regulatory agency of the U.S. Department of Commerce, researchers attempted to evaluate the performance of facial recognition algorithms on faces partially covered by protective masks. They report that even the best of the 89 commercial facial recognition algorithms they tested had error rates between 5% and 50% in matching digitally applied masks with photos of the same person without a mask. From a report: "With the arrival of the pandemic, we need to understand how face recognition technology deals with masked faces," Mei Ngan, a NIST computer scientist and a coauthor of the report, said in a statement. "We have begun by focusing on how an algorithm developed before the pandemic might be affected by subjects wearing face masks. Later this summer, we plan to test the accuracy of algorithms that were intentionally developed with masked faces in mind."

The study -- part of a series from NIST's Face Recognition Vendor Test (FRVT) program conducted in collaboration with the Department of Homeland Security's Science and Technology Directorate, the Office of Biometric Identity Management, and Customs and Border Protection -- explored how well each of the algorithms was able to perform "one-to-one" matching, where a photo is compared with a different photo of the same person. (NIST notes this sort of technique is often used in smartphone unlocking and passport identity verification systems.) The team applied the algorithms to a set of about 6 million photos used in previous FRVT studies, but they didn't test "one-to-many" matching, which is used to determine whether a person in a photo matches any in a database of known images. Because real-world masks differ, the researchers came up with nine mask variants to test, which included differences in shape, color, and nose coverage.

Humans on the moon and Mars would face the problem of damaging space radiation.

But new research suggests one possible solution to the fact that "Space wants to kill you," according to CNET: To protect astronauts, scientists have been studying an unusually hardy organism, discovered in one of the most radioactive places on the planet: Chernobyl... In some parts of the plant, the level of radiation spiked so high that exposure would kill a human in about 60 seconds. But several species of fungi have been discovered in the reactor. And they're thriving, "feeding" on the extreme levels of radiation. A new study, yet to undergo peer review, was published on the pre-print repository bioRxiv on July 17 and examines one of these species, Cladosporium sphaerospermum. It suggests the fungi could be used as a self-healing, self-replicating shield to protect astronauts in deep space...

Researchers placed the fungi aboard the ISS for 30 days and analyzed its ability to block radiation... The proof-of-concept study showed that the fungi was able to adapt to microgravity and thrive on radiation. It was able to block some of the incoming radiation, decreasing the levels by almost 2%. One of the major advantages, the researchers write, is the fungi self-replicates from microscopic amounts. You would only need to send a small amount to orbit, give it some nutrients and let it replicate, forming a biological radiation shield. With some tweaking, the fungi could be used to shield bases on the moon or Mars.

It's a long while until we put boots on the red planet, but the groundwork is being laid now.

Jennifer Riggins is participating in the Oxford Vaccine Trial. She's an American technology journalist and marketer who's self-employed in London — and she's also agreed to answer some questions from Slashdot!

Slashdot: Can you give me any details on what it's like when you go in for your shots? (Like, are they somber, or enthusiastic...?) Do you chat at all? Do they know you by name?

JR: For sure they know me by name, at least after glancing at charts or if I call the hotline. The doctors and nurses don't know which dose I got — this COVID vaccine or the placebo which is the meningitis vaccine. It's their job to make me feel comfortable so I stay volunteering and they can get as much info from me (like about reactions) as they can.

It's actually a lot of fun for me. I love the medical talk and ask loads of questions and they are totally transparent and kind.

Plus working from home with my also full-time-working husband and our three year old during the pandemic, a surprise benefit is a bit of me time including the hour-long walk to hospital each way.

Slashdot: Have you ever made contact with any of the other participants?

JR: Just a nod "hello" here and there. No one I've seen chats like me — ha. But also we are kept far apart because, you know, pandemic.

And Jennifer had a lot more to say about her experience, the rewards, the reactions, and the media coverage of it all...

"DNA is millions of times more efficient at storing data than your laptop's magnetic hard drive," reports Popular Mechanics.

"Since DNA can store data far more densely than silicon, you could squeeze all of the data in the world inside just a few grams of it." In a new paper published this week in the journal Proceedings of the National Academy of Sciences, Ilya Finkelstein, an associate professor of molecular biosciences at the University of Texas at Austin and company detail their new error correction method... They were able to store the entirety of The Wizard of Oz, translated into Esperanto, with more accuracy than prior DNA storage methods ever could have. We're on the yellow brick road toward the future of data storage.

Researchers at the University of Texas at Austin are certainly not the first to have encoded a work of art onto strands of DNA... [A] team of researchers from Microsoft and the University of Washington fit 200 megabytes of data onto lengths of DNA, including the entirety of War and Peace. In March 2019, they even came up with the first automated system for storing and retrieving data in the manufactured genetic material. Today, other major technology firms are also working in the space, including both IBM and Google. The ultra-secretive U.S. Intelligence Advanced Research Projects Activity — the government's version of DARPA, but for spies — is even invested in the work. These researchers envision a future where some of the most precious, but rarely accessed data, can be stored in vials of DNA, only pulled down from the cool, dark storage of the lab, as needed....

Because there are four building blocks in DNA, rather than the binary 1s and 0s in magnetic hard drives, the genetic storage method is far more dense, explains John Hawkins, another co-author of the new paper. "A teaspoon of DNA contains so much data it would require about 10 Walmart Supercenter-sized data centers to store using current technology," he tells Popular Mechanics. "Or, as some people like to put it, you could fit the entire internet in a shoe box." Not only that, but DNA is future-proof. Hawkins recalls when CDs were the dominant storage method, back in the 1990s, and they held the promise that their storage could last forever, because plastic does (but scratches can be devastating). Data stored on DNA, on the other hand, can last for hundreds of thousands of years. In fact, there is a whole field of science called archaeogenetics that explores the longevity of DNA to understand the ancient past... DNA storage doesn't require any energy, either — just a cool, dark place to hang out until someone decides to access it. But the greatest advantage, Hawkins says, is that our ability to read and write DNA will never become obsolete....

But like all data storage methods, DNA has a few shortcomings as well. The most significant upfront hurdle is cost. Hawkins says that current methods are similar to the cost for an Apple Hard Disk 20 back in 1980. Back then, about 20 megabytes of storage — or the amount of data you'd need to use to download a 15-minute video — went for about $1,500.

"NASA's Juno Jupiter probe has captured unprecedented views of the largest moon in the solar system," reports Space.com: During a close flyby of Jupiter on Dec. 26, 2019, Juno mapped the north polar regions of the icy satellite Ganymede in infrared light, something no other spacecraft had done before. The data, which Juno gathered using its Jovian Infrared Auroral Mapper (JIRAM) instrument, show that Ganymede's northern reaches are very different than locales closer to the equator of the moon, which is bigger than the planet Mercury. "The JIRAM data show the ice at and surrounding Ganymede's north pole has been modified by the precipitation of plasma," Alessandro Mura, a Juno co-investigator at the National Institute for Astrophysics in Rome, said in a statement.

"It is a phenomenon that we have been able to learn about for the first time with Juno because we are able to see the north pole in its entirety."

This plasma consists of charged particles from the sun, which have been trapped by Jupiter's powerful magnetic field. Unlike any other moon, the 3,274-mile-wide (5,269 kilometers) Ganymede has a magnetic field of its own, which funnels the plasma toward its poles. A similar phenomenon occurs here on Earth, which explains why the auroras occur at high latitudes on our planet. But Ganymede has no atmosphere to obstruct and be lit up by these particles, so they slam hard into the ice at and around both poles.
The article notes that the $1.1 billion Juno probe "launched in August 2011 and arrived at Jupiter in July 2016."

"A European and NASA spacecraft has snapped the closest pictures ever taken of the sun," reports the Associated Press, "revealing countless little 'campfires" flaring everywhere. Scientists on Thursday released the first images taken by Solar Orbiter, launched from Cape Canaveral in February. The orbiter was about 48 million miles from the sun — about halfway between Earth and the sun — when it took the stunning high-resolution pictures last month... European Space Agency project scientist Daniel Muller described the observed multitude of "campfires" shooting into the corona, or sun's crown-like outer atmosphere, as quite possibly "the tiny cousins of the solar flares that we already know." Millions if not billions of times smaller, these tiny flares may be heating the corona, he said, long known to be hundreds of times hotter than the actual solar surface for unknown reasons... These so-called campfires, Berghmans noted, are "literally everywhere we look." Not yet well understood, they could be mini explosions, or nanoflares. More measurements are planned.

The $1.5 billion spacecraft will tilt its orbit as the mission goes on, providing unprecedented views of the sun's poles. This vantage point will allow it to capture the first pictures of the solar poles.

IEEE Spectrum reports: There's still plenty that can disrupt radio communications... Rather than waiting for a human on Earth to tell the radio how to adapt its systems — during which the commands may have already become outdated — a radio with a neural network can do it on the fly. Such a device is called a cognitive radio. Its neural network autonomously senses the changes in its environment, adjusts its settings accordingly — and then, most important of all, learns from the experience... Worcester Polytechnic Institute and Penn State University, in cooperation with NASA, recently tested the first cognitive radios designed to operate in space and keep missions in contact with Earth. In our tests, even the most basic cognitive radios maintained a clear signal between the International Space Station (ISS) and the ground. We believe that with further research, more advanced, more capable cognitive radios can play an integral part in successful deep-space missions in the future, where there will be no margin for error...

Our own effort to create a proof-of-concept cognitive radio for space communications was possible only because of the state-of-the-art Space Communications and Navigation (SCaN) test bed on the ISS. NASA's Glenn Research Center created the SCaN test bed specifically to study the use of software-defined radios in space. The test bed was launched by the Japan Aerospace Exploration Agency and installed on the main lattice frame of the space station in July 2012... Ours would be the first-ever cognitive radio experiments conducted in space...

During the tests, the cognitive radio clearly showed that it could learn how to maintain a communications link. The radio autonomously selected settings to avoid losing contact, and the link remained stable even as the radio adjusted itself...

Overall, the success of our tests on the SCaN test bed demonstrated that cognitive radios could be used for deep-space missions.

"The U.S. wants to build nuclear power plants that will work on the moon and Mars, and on Friday put out a request for ideas from the private sector on how to do that," reports Time magazine: The U.S. Department of Energy put out the formal request to build what it calls a fission surface power system that could allow humans to live for long periods in harsh space environments.

The Idaho National Laboratory, a nuclear research facility in eastern Idaho, the Energy Department and NASA will evaluate the ideas for developing the reactor. The lab has been leading the way in the U.S. on advanced reactors, some of them micro reactors and others that can operate without water for cooling. Water-cooled nuclear reactors are the vast majority of reactors on Earth. "Small nuclear reactors can provide the power capability necessary for space exploration missions of interest to the Federal government," the Energy Department wrote in the notice published Friday...

The goal is to have a reactor, flight system and lander ready to go by the end of 2026... Officials say operating a nuclear reactor on the moon would be a first step to building a modified version to operate in the different conditions found on Mars.

"A photo and film restoration specialist, who goes by the name of DutchSteamMachine, has worked some AI magic to enhance original Apollo film, creating strikingly clear and vivid video clips and images," reports Universe Today: Take a look at this enhanced footage from an Apollo 16 lunar rover traverse with Charlie Duke and John Young, where the footage that was originally shot with 12 frames per second (FPS) has been increased to 60 FPS... And I was blown away by the crisp view of the Moon's surface in this enhanced view of Apollo 15's landing site at Hadley Rille... Or take a look at how clearly Neil Armstrong is visible in this enhanced version of the often-seen "first step" video from Apollo 11 taken by a 16mm video camera inside the Lunar Module...

The AI that DutchSteamMachine uses is called Depth-Aware video frame INterpolation, or DAIN for short. This AI is open source, free and constantly being developed and improved upon... "People have used the same AI programs to bring old film recordings from the 1900s back to life, in high definition and colour," he said. "This technique seemed like a great thing to apply to much newer footage...."

DutchSteamMachine does this work in his spare time, and posts it for free on his YouTube page. His tagline is "Preserving the past for the future..." And he's planning to keep it all coming. "I plan to improve tons of Apollo footage like this," he said. "A lot more space and history-related footage is going to be published on my YT channel continuously." He also has a Flickr page with more enhanced imagery. [And a Patreon page...]
Long-time Slashdot reader schwit1 calls it "similar to what Peter Jackson did with old World War I footage for They Shall Not Grow Old ."

"Comet Neowise has been the brightest and most visible space snowball in a generation, but it's also the first naked-eye comet to visit us in the new era of satellite mega-constellations like SpaceX's Starlink," writes CNET.

"In just the latest episode of Starlink 'trains' irritating astronomers, a number of images have been circulating of the satellites photo-bombing Comet Neowise glamour shots..."

Live Science explains: Visible just above the horizon right now, the comet appears faint and small to the naked eye, but can be seen clearly through cameras with long, telephoto lenses. Usually, when photographers capture objects like this in the night sky they use long exposure times, leaving the camera aperture open to collect light over the course of several seconds. But now comet-chasers report that a new fleet of SpaceX's Starlink satellites is leaving bright smears across their NEOWISE snaps, as the shiny orbiters streak through their frames during long exposures.

Long-time Slashdot reader schwit1 shared this article from HealthDay: In earlier studies, patients have pegged CPR survival rates at between 19% and 75%. But the real rate of survival is about 12% for cardiac arrests that occur outside hospitals and between 24% and 40% for those that happen in the hospital, according to the report published online July 13 in the Emergency Medicine Journal.

For the new study, Bandolin's team surveyed 500 emergency department patients and their companions. Fifty-three percent said they had done or witnessed CPR, and 64% had taken a CPR course. Ninety-five percent said their main source of CPR information was television. About half said the success rate of CPR topped 75%. And nine out of 10 said they wanted to receive CPR if it was needed.

But only 28% had discussed CPR with a doctor, the investigators noted in a journal news release.

"Researchers have spotted large waves of martian sand migrating for the first time," reports Science magazine.

"The discovery dispels the long-held belief that these 'megaripples' haven't moved since they formed hundreds of thousands of years ago. They're also evidence of stronger-than-expected winds on the Red Planet." It's pretty staggering that humans can detect these changes on Mars, says Ralph Lorenz, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory who was not involved in the research. "We can now measure processes on the surface of another planet that are just a couple times faster than our hair grows...."

Since the early 2000s, Mars rovers and orbiters have repeatedly spotted megaripples on the Red Planet. But they didn't seem to change in any measurable way, which led some scientists to think they were relics from Mars's past, when its thicker atmosphere permitted stronger winds. Now, using images captured by NASA's Mars Reconnaissance Orbiter, Simone Silvestro, a planetary scientist at Italy's National Institute of Astrophysics in Naples, and his colleagues have shown that some megaripples do creep along — just very slowly. The researchers focused on two sites near the equator of Mars... Megaripples in both regions advanced by about 10 centimeters per year, the team reports in the Journal of Geophysical Research: Planets...

It's a surprise that megaripples move at all on Mars, says Jim Zimbelman, a planetary geologist at the Smithsonian Institution's Air and Space Museum. Just a few decades ago, there was no evidence that sands on Mars were mobile, he says. "None of us thought that the winds were strong enough...." Atmospheric models of Mars suggest winds capable of moving sand are rare. This discovery of migrating megaripples will force those models to be revised, the team suggests....

Megaripples on the move are beacons of windy conditions, which might in turn kick-start dust storms, the researchers suggest. Airborne dust can blanket solar panels, reducing their efficiency, and it can also gum up mechanical parts like gears. That's bad news for Mars rovers and human habitats alike.

When asked for the most efficient way to sort a million 32-bit integers in 2008, then-presidential candidate Barack Obama answered, "I think the bubble sort would be the wrong way to go."

But people are still searching for the best possible sorting algorithms, explains Slashdot reader scandum: Long has the conviction been held that quicksort is faster than merge sort. Timsort (derived from merge sort and insertion sort) was introduced in 2002 and while slower than quicksort for random data, Timsort performs better on ordered data.

Quadsort (derived from merge sort) was introduced in 2020 and is faster than quicksort for random data, and slightly faster than Timsort on ordered data.

Also of notice is the significant performance difference on small arrays, quadsort is on average two times faster than Timsort on data sets between 10 and 1000 elements. Quadsort achieves this performance through several optimizations spread out over 1500 lines of code that get the maximum performance out of merge sort.
Quadsort's GitHub page explains: After the first round of sorting a single if check determines if the four swap variables are sorted in order, if that's the case the swap finishes up immediately. Next it checks if the swap variables are sorted in reverse-order, if that's the case the sort finishes up immediately. If both checks fail...two checks remain to determine the final order.

The New York Times has created a surprising interactive analysis of the number of coronavirus cases (per million residents) in different countries: With its cases surging since mid-June, the United States is squarely in the top 10. Leading the outbreak now are countries in the Persian Gulf, where the virus has spread rapidly among foreign laborers. [Oman, Bahrain, and Kuwait.] Rounding out the top 10 are South Africa, Israel and several countries in Latin America. [Panama, Brazil, Colombia, Bolivia]

The current U.S. outbreak is especially stark when compared to other large, high-income countries. All have few cases today compared to the United States... Italy and Spain saw some of the worst early outbreaks, before strict control measures brought cases down. Now, some schools are open, adults are back at work and tourists are on vacation. Even Sweden, where cases surged after the government chose to forgo the strict lockdowns of its neighbors, has seen cases drop.

The surge in the United States is so extreme that, once adjusted for population, these 10 states are recording more new cases than any country in the world. [Florida, Louisiana, Mississippi, Nevada, Arizona, Alabama, South Carolina, Texas, Idaho, and Tennessee].

An anonymous reader shares a report: The anecdotes are alarming. A woman in Los Angeles seemed to recover from Covid-19, but weeks later took a turn for the worse and tested positive again. A New Jersey doctor claimed several patients healed from one bout only to become reinfected with the coronavirus. And another doctor said a second round of illness was a reality for some people, and was much more severe. These recent accounts tap into people's deepest anxieties that they are destined to succumb to Covid-19 over and over, feeling progressively sicker, and will never emerge from this nightmarish pandemic. And these stories fuel fears that we won't be able to reach herd immunity -- the ultimate destination where the virus can no longer find enough victims to pose a deadly threat.

But the anecdotes are just that -- stories without evidence of reinfections, according to nearly a dozen experts who study viruses. "I haven't heard of a case where it's been truly unambiguously demonstrated," said Marc Lipsitch, an epidemiologist at the Harvard T.H. Chan School of Public Health. Other experts were even more reassuring. While little is definitively known about the coronavirus, just seven months into the pandemic, the new virus is behaving like most others, they said, lending credence to the belief that herd immunity can be achieved with a vaccine. It may be possible for the coronavirus to strike the same person twice, but it's highly unlikely that it would do so in such a short window or to make people sicker the second time, they said. What's more likely is that some people have a drawn-out course of infection, with the virus taking a slow toll weeks to months after their initial exposure. People infected with the coronavirus typically produce immune molecules called antibodies. Several teams have recently reported that the levels of these antibodies decline in two to three months, causing some consternation. But a drop in antibodies is perfectly normal after an acute infection subsides, said Dr. Michael Mina, an immunologist at Harvard University.

NASA has announced that the often delayed James Webb space telescope (JWST) is to be delayed once more. Instead of a launch on 30 March 2021, the mission has now slipped to 31 October 2021. From a report: The seven-month delay is the result of impacts from the coronavirus pandemic, as well as technical challenges. The spacecraft is currently being tested at Northrop Grumman, NASA's main industrial partner on the mission, in Redondo Beach, California. A recently completed risk assessment exercise recommended the delay. Once ready, JWST will be transported to Europe's spaceport in Kourou, French Guiana, where it will be launched by the European Space Agency on an Ariane 5 ECA rocket. Touted as the successor to the Hubble space telescope, JWST has had a troubled development characterised by major cost overruns and delays. Development work started in the late 1990s, with a launch date set for 2007.