Aqueous film-forming foam (AFFF), a powerful fire suppressant, is currently being phased out of use by the U.S. military. The foam is a major source of PFAS contamination in drinking water around the country. Image Credit: FEMA/U.S. Fire Administration

<p>What makes PFAS chemicals extremely useful—and extremely hard to get rid of—are the bonds between carbon and fluorine atoms that are almost impossible to break.</p>

Toxic synthetic 'forever chemicals' are in our water and on our plates

Saplings at Karin Nursery outside Yerevan, Armenia. Image courtesy of the Armenia Tree Project

<p>A four-year fuel blockade in the 1990s threatened the tiny country’s forests. Ever since, it’s been replanting its trees—a task that’s more complicated than expected.</p>

Armenia reckons with climate change and its Soviet past through reforestation

An animation of the OSIRIS-REx sampling arm touching down on the surface of asteroid Bennu to collect a sample of fine-grained material. Image Credit: NASA/Goddard/CI Lab

<p>Despite concerns that the surface of Bennu might be too rocky, the probe’s touchdown produced a dramatic shower of debris, opening the way for future insights into the mysteries of our solar system.</p>

In a swirl of rocks and dust, OSIRIS-REx probe touches an asteroid

Koch Foundation

NOVA Science Trust Logo

Draper

<p>NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology. Launched in 2012, we feature in-depth articles and commentaries from some of the most respected journalists, scientists, and engineers. NOVA Next explores the ideas that are changing the future, from the frontiers of synthetic biology to the politics of personalized medicine.</p><p>Let us know what you think. We’re listening on <a href="http://www.facebook.com/NOVAonline">Facebook</a>, <a href="http://twitter.com/novapbs">Twitter</a>, and email.</p><p>If you’re a journalist and have an idea for a story, send it our way.</p>

NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology.

NOVA Next

<p>NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology.</p>

A person is tested for COVID-19 at a drive-thru testing site in Florida in July 2020. Image Credit: Paul Hennessy/NurPhoto, Getty Images

<p>Figuring out when to get tested after exposure requires understanding what happens once the virus enters your body. We’ve got you covered.</p>

I’ve been exposed to Covid-19. When should I get tested?

<p>Asteroid samples and strange space molecules wowed us—while past epidemics taught us valuable lessons.</p>

NOVA’s top 5 science stories of 2020





  
      <p>On Sunday morning, Japan’s Hayabusa2 space probe dropped a capsule from space, delivering an asteroid sample to Earth.</p><p>The capsule “streaked through the atmosphere at high speeds before deploying a parachute,” Charlotte Jee <a href="https://www.technologyreview.com/2020/12/07/1013316/japan-hayabusa-2-ryugu-asteroid-space/">writes for MIT Technology Review</a>. At 4:37 a.m. local time, the capsule, containing up to several grams of rock, dust, and debris, landed in the red desert sand of the Australian Outback town of Woomera, 280 miles north of Adelaide.</p><p>A recovery team, led by the Japan Space Agency (JAXA), deployed a helicopter before sunrise to locate and collect it. They carried the capsule by hand into a facility to be cleaned and dismantled, exposing the interior sample container, Masaki Fujimoto, deputy director general of JAXA&#x27;s Institute of Space and Astronautical Science, said during a news conference.</p><p>The event marks the end of a six-year, 3.25 billion-mile mission in space. Its team of scientists hopes to unravel the mysteries of our solar system’s early days—asteroids provide hints about the <a href="https://www.pbs.org/wgbh/nova/video/asteroids-provide-hints-about-ingredients-planets/">“ingredients” in planets</a>, astronomers say—while also exploring the origins of life on Earth. JAXA scientists hope to have collected at least 0.1 grams of asteroid debris to do so. Analyses this week will reveal if they met that goal.</p>
            <figure class="richtext-image full-width"><img alt="shutterstock_editorial_11207548d.jpg" class="richtext-image full-width" height="533" width="800"
            src="https://www.pbs.org/wgbh/nova/media/images/shutterstock_editorial_11207548d.width-800.jpg"/><figcaption><p>Japan Space Agency team members recover the Hayabusa2 re-entry capsule, which contains samples from asteroid Ryugu, on Sunday, Dec. 5, 2020. Image credit: JAXA, via Shutterstock</p><div class="credit"></div></figcaption>
            </figure>
            <p>“Even with the capsule in hand, there is a bit of a rush,” Kenneth Chang <a href="https://www.nytimes.com/2020/12/05/science/japan-asteroid-hayabusa2-woomera.html?smtyp=cur&amp;smid=fb-nytscience">writes for the New York Times</a>. “The team wanted to whisk it back to Japan within 100 hours after the landing. Even though the container is sealed, the worry is that Earth air will slowly leak in,” potentially leading to contamination.</p><p>The sample originated from Ryugu, a dark, carbon-rich asteroid 180 million miles away from Earth. After launching in 2014, Hayabusa2 reached Ryugu in June 2018. From there, it spent 18 months circling the 0.6-mile-wide diamond-shaped asteroid, making remote observations. Hayabusa2 also released several small robots onto Ryugu to collect data, images, and ultimately scout its craggy face for potential sampling sites. Unlike traditional rovers on wheels, Hayabusa2’s robots traversed Ryugu’s rubbly surface by hopping.</p><p></p>
  

  
      <div class="related"></div>
  

  
      <p>“The whole robot can rotate, kick the surface and then jump,” Yuichi Tsuda, Hayabusa2 project manager at JAXA, <a href="https://www.pbs.org/wgbh/nova/video/touching-the-asteroid/">told NOVA</a>.</p><p>In February 2019, after identifying a safe spot for a pinpoint landing between closely spaced boulders, the Hayabusa2 team made its first attempt to collect a sample by having a sampling device on the belly of the spacecraft lightly touch down on the asteroid, firing a projectile, and collecting the resulting ejected material with a “catcher” at the top of the sampling device. “I remember the scream of my Japanese colleagues when we knew this was a success,” Patrick Michel, a co-investigator of the Hayabusa2 and NASA’s <a href="https://www.pbs.org/wgbh/nova/article/osiris-rex-bennu-asteroid-touchdown/">OSIRIS-REx asteroid mission</a> told NOVA.</p><p>Then, in July 2019, the spacecraft went back for more rocks and rubble. This time, it collected the first-ever subsurface sample from an asteroid, extracting material from an artificial crater made by firing a copper projectile into Ryugu’s surface.</p><p>From these samplings, the JAXA team aimed to collect a total of 100 milligrams of “carbon-rich soil and rock fragments,” Dennis Normile <a href="https://www.sciencemag.org/news/2020/12/japan-s-hayabusa2-capsule-lands-carbon-rich-asteroid-samples">writes for Science Magazine</a>. “Just how much material was collected won’t be known until the sample container—the ‘treasure box’—is opened in clean room facilities in Tokyo this week,” Normile writes.</p><p>Ryugu is a carbonaceous, or C-type, asteroid. Space rocks of this kind are abundant in our solar system, generally dwelling in the asteroid belt between Mars and Jupiter. But some, like Ryugu, orbit closer to the sun, roughly between Earth and Mars. These are considered “near-Earth asteroids.” They contain hydrates (inorganic salts that contain water molecules) and organic materials—Ryugu is one of the darkest asteroids researchers have ever found, “its inky complexion a result of all the <a href="https://www.liebertpub.com/doi/10.1089/ast.2019.2198">carbon trapped in organic compounds</a> smeared across its surface,” Daniel Oberhaus <a href="https://www.wired.com/story/for-the-second-time-ever-an-asteroid-sample-returns-to-earth/">writes for WIRED</a>. Scientists suspect that when asteroids like Ryugu pummeled a proto-Earth billions of years ago, they may have helped kick-start life by delivering the necessary building blocks.</p><p>While life on Earth uses only 20 amino acids, “we see many more in asteroids,” Jamie Elsila Cook, co-investigator for the NASA Astrobiology Institute at the Goddard Center for Astrobiology, said during an OSIRIS-REx mission press conference in October. (Like Hayabusa2, NASA’s OSIRIS-REx aims to bring an asteroid sample back to Earth.) “We know they’re present in carbonaceous meteorites, so they’re extraterrestrial compounds vital to life here on Earth.”</p>
  

  
      <div class="ad"></div>
  

  
      <p>Meteorites that land on Earth originate from asteroids. We can get a peek at what asteroids contain when they bump into each other, break apart, and send debris crashing to Earth—what we call meteorites. But having traveled through Earth’s atmosphere to eventually crash land on its surface, meteorites are both cooked to a crisp and corrupted by terrestrial chemistry. “Sending a probe to a still-orbiting asteroid is the best way to collect a clean sample,” Oberhaus writes.</p><p>Sampling Ryugu and other asteroids directly can also help us gain a broader understanding of our solar system. “By understanding better how and why Ryugu gained its current appearance, we’ll have a more comprehensive model for how solar system bodies form and develop,” planetary scientist Paul K. Byrne <a href="https://theconversation.com/touching-the-asteroid-ryugu-revealed-secrets-of-its-surface-and-changing-orbit-137852">writes for the Conversation</a>.</p><p>Hayabusa2 follows in the footsteps of Hayabusa, the world’s first asteroid sample return mission, which JAXA launched in 2003. Due to a failure in the Hayabusa spacecraft’s collection mechanism, only a few micrograms—about 1,500 individual grains—of dust from Itokawa, an oblong and stony (S-type) asteroid, made it back to Earth in 2010.</p><p>“Hayabusa was like Apollo 13; it was a successful failure,” OSIRIS-REx scientist Bashar Rizktold told NOVA. “I mean, they had so many things go wrong, yet they still managed to get the spacecraft back to Earth.”</p><p>Like Hayabusa2, NASA’s OSIRIS-REx mission, which successfully grabbed a 2-pound sample from asteroid Bennu in October, hopes to unravel mysteries of our solar system by analyzing asteroids’ ingredients. (While Hayabusa2 scientists had no means to measure their sample remotely, OSIRIS-REx is equipped with cameras, whose images helped discern the substantial <a href="https://www.pbs.org/wgbh/nova/article/nasa-osiris-rex-spacecraft-stow-asteroid-bennu-sample-early/">size of the Bennu sample</a> days after its collection.) A diamond-shaped carbonaceous asteroid covered in boulders, Bennu looks like Ryugu’s half-sized twin. Some scientists posit that the two come from a single parent body that was struck by another space rock millions of years ago, and broke into tiny pieces, which gravity helped reform into individual asteroids.</p><p>But there’s a major difference between Bennu and Ryugu: While OSIRIS-REx has detected minerals inside Bennu’s rocky surface that contain the remnants of water, an important ingredient for life, Ryugu appears to be parched.</p>
            <figure class="richtext-image full-width"><img alt="Hayabusa2 and asteroid Ryugu visualization" class="richtext-image full-width" height="450" width="800"
            src="https://www.pbs.org/wgbh/nova/media/images/Hayabusa_2_and_an_asteroid_-_visualization.width-800.jpg"/><figcaption><p>A visualization of the Hayabusa 2 probe and asteroid Ryugu. Image credit: Deutsches Zentrum für Luft- und Raumfahrt (DLR), via Wikimedia Commons</p><div class="credit"></div></figcaption>
            </figure>
            <p>Given the Hayabusa2 and OSIRIS-REx mission scientists’ common goal, the two teams have worked together over the past couple of years. “Two science missions isn’t just twice as good,” Heather Enos, OSIRIS-REx deputy principal investigator, said in a <a href="http://cosmos.isas.jaxa.jp/the-x-factor-the-collaboration-between-hayabusa2-and-osiris-rex/">2018 press release</a>. “It’s two times a factor of ‘X’ as good! You’ve got so much talent, information and diversification within the teams that your knowledge base can explode.”</p><p>And with some scientists, like Patrick Michel, participating in both Hayabusa2 and the OSIRIS-REx mission, there’s hope that lessons learned from the Ryugu sample analysis can be applied to the eventual study of rock and dust from Bennu, which the OSIRIS-REx spacecraft will drop down to the Utah desert in September 2023.</p><p>By then, as part of its post-Ryugu “bonus mission,” Hayabusa2 will be well on its way to a large red asteroid named 2001 CC21, which it will fly by in July 2026. Next, the craft will swing back around Earth to eventually rendezvous with the tiny asteroid 1998 KY26, a mere 1/30th the size of Ryugu, in 2031. Despite the asteroid’s small size, measurements taken on Earth hint that KY26 may have something Ryugu does not: water.</p><p>Hayabusa2 has one more asteroid sampling device onboard, and as the mission nears its end over a decade from now, the probe may deliver yet another asteroid sample to Earth.</p>
  

  
      <div class="newsletter"></div>
  



Rendering of JAXA's Hayabusa2 probe with Earth behind it. Image credit: DLR German Aerospace Center (CC-BY 3.0), via Flickr

<p>The sample, which is the second-ever to be successfully taken from a space rock and ferried back to Earth, could teach us about the origins of life.</p>

Japan’s Hayabusa2 returns asteroid sample to Earth in “perfect condition”





  
      <p>At the Neolithic village of <a href="https://blog.historicenvironment.scot/2016/05/3d-4d-digital-monitoring-sea-defences-skara-brae/">Skara Brae</a> off the northern coast of Scotland, serpentine green slopes overlay the remains of a community so complete that many of the houses feature stone beds, dressers, and cupboards—even though the village is older than both Stonehenge and the pyramids of Giza. The site, which was once home to some 50 people, overlooks the blustery Bay of Skaill. Over the millennia, wind and water have slowly eaten into the hills around the ruins, putting them at risk of eventual destruction.</p>
  

  
      <div class="related"></div>
  

  
      <p>For the last decade, the preservation organization Historic Environment Scotland (HES) has been visiting Skara Brae deveoping strategies to protect what’s sometimes known as the “Scottish Pompeii” from encroaching erosion. One of their most successful efforts has nothing to do with wood or stone and everything to do with light. Every two years, HES conservators bring laser scanners to the remote northern island to gather a 3D image of Skara Brae, including both its structures and the surrounding dunes and cliffs. Comparing the resulting data set to its predecessors has helped them identify to the millimeter how the landscape has changed.</p><p>“To be able to monitor what’s going on is essential,” says Sophia Mirashrafi, who helps coordinate <a href="https://www.engineshed.scot/about-us/teams/digital-documentation-and-digital-innovation/the-rae-project/">HES’s digital projects</a> and get them ready for presentation to the public. “Scanning doesn’t stop the water from eroding the site, but it can be used to help inform decisions about how it can be protected.” She and her team also used the scans—known as point-cloud models—to create interactive virtual experiences that give the public up-close access to parts of the village.</p><p>When we think about preserving cultural heritage, Mirashrafi says, we usually think about the physical: propping up carved stone, reconstructing rotted wood, uncovering precious metal. But, just as it’s being used at Skara Brae, laser scanning (also known as LIDAR) has become an essential tool at cultural sites around the world, from Notre Dame to Rapa Nui, in augmenting physical preservation, helping conservators make better decisions, and enriching experiences of the sites for both scientists and the public.</p>
            <figure class="richtext-image full-width"><img alt="Aerial digital map of Skara Brae" class="richtext-image full-width" height="565" width="800"
            src="https://www.pbs.org/wgbh/nova/media/images/SkaraBraePlan_Pointcloud.width-800.jpg"/><figcaption><p>Historic Environment Scotland has used drones equipped with LIDAR scanners and photogrammetry to create aerial 3D models of the Skara Brae Neolithic site, which is older than Stonehenge. Image courtesy of Historic Environment Scotland </p><div class="credit"></div></figcaption>
            </figure>
            <p></p>
  

  
      <p>At the most basic level, a point-cloud model is a collection of 3D coordinates that conservators, art historians, and researchers can use to “sample reality,” says architect and computer scientist Livio De Luca, who heads the vast team of <a href="https://www.sciencemag.org/news/2020/03/scientists-are-leading-notre-dame-s-restoration-and-probing-mysteries-laid-bare-its">scientists racing to preserve</a> Notre Dame Cathedral in Paris after the catastrophic fire that destroyed its roof in April 2019. Laser sensors mounted on rotating heads collect data on more than 100 three-dimensional points per second over a 180-degrees axis by measuring the amount of time it takes for light to leave the sensor, bounce off a given spot on a structure or object, and return.</p><p>Users move scanners of different resolutions (some for capturing fine details, other for larger landscapes) gradually around the site to produce a digital cloud of points. Each data set overlaps with the last, allowing them to combine those data sets in an algorithmic process called registration, and create a 360-degree “picture” of that site—kind of like doing a 3D jigsaw puzzle. Even though the lasers collect so much data so quickly, the process is still slow and painstaking. It took a team more than two weeks to scan Notre Dame, De Luca says, using some 400 scanning stations to capture as many data points as possible.</p><p>After the initial puzzle is done, the next step is to turn the cloud of points into a “watertight mesh” using a computer program—converting them from a dense constellation to an interconnected surface. Conservators often combine this mesh with data from another digital data-gathering technique called photogrammetry, which can harvest information about a structure’s texture, color, and general shape from overlapping photos of that structure. </p><p>LIDAR (which stands for Light Detection and Ranging) “gives you quantifiable accuracy,” says architect and computer engineer John Ristevski, CEO of the digital heritage nonprofit CyArk, whose mission revolves around scanning sites of historical and cultural interest around the world. “In contrast, photogrammetry provides great textures and beautiful geometry, but it’s not completely reliable. We want both.”</p>
  

  
      <div class="ad"></div>
  

  
      <p>As the technology has improved, point-cloud models have come to play an essential role when heritage sites are damaged. Ristevski’s colleagues at CyArk finished scanning one of <a href="https://artsexperiments.withgoogle.com/bagan/">Bagan, Myanmar’s huge stone temples</a> just three months before a 7.1 magnitude earthquake hit the city in 2016. Using <a href="https://www.youtube.com/watch?v=N5Y33-VvsbA">their scans</a>, CyArk was able to create detailed assessments of the damage and help with plans for restoration. Similarly, a Vassar professor, a 3D tourism company, and the company that makes the video game Assassin’s Creed had all <a href="https://www.youtube.com/watch?v=QBzKsTZ81Sw">scanned Notre Dame Cathedral</a> before its fire. “The point cloud represents the main source to rebuild something, using geometrical information in a precise and accurate way,” De Luca says. “If by other kinds of restoration we were able to approximate shapes in the past, now we’re able to reproduce shapes millimeter by millimeter.”</p><p>Point-cloud modeling can also help conservators do experiments that would be impossible in real life. At Notre Dame, a new phase of reconstruction began this month to rebuild the stone ribs that once held up arches in the ceiling. Before this effort begins in earnest, members of the cathedral team will scan each individual stone, a process that will allow them to rebuild the ribs virtually—ensuring they do not compromise the rest of the structure before they are rebuilt in real life. “We’re able to more safely and, from a scientific point of view, more accurately test how they will behave in rebuilding,” De Luca says.</p><p>For HES, point-cloud modeling has not just been essential in erosion monitoring; it has also become an important teaching tool. Using LIDAR scanners and drones capable of photogrammetry, the organization has been able to scan the tops of walls (known as “wall heads”), allowing conservators a much more complete view of the structure than ever possible before. “Scaffolding is very expensive, and it’s difficult to get people up there,” says Mirashrafi. Having access to point-cloud models of the upper parts of the buildings has allowed conservators and stone masons working on the many sites HES cares for to get up close to ceilings they couldn’t access otherwise and to better monitor the health of those wall heads—even using their virtual counterparts as teaching tools for masons-in-training.</p>
            <figure class="richtext-image full-width"><img alt="Digital image of row of stone statues" class="richtext-image full-width" height="394" width="800"
            src="https://www.pbs.org/wgbh/nova/media/images/Ahu_Nau_Nau2.width-800.jpg"/><figcaption><p>Staffers from the digital heritage nonprofit CyArk traveled to Rapa Nui (Easter Island) in early 2020. There, they taught workshops in point-cloud modeling, which will allow local resource managers and Indigenous groups to monitor the erosion of the island’s 500 moai, or enormous, ancient stone statues. Image Credit: CyArk</p><div class="credit"></div></figcaption>
            </figure>
            <p></p>
  

  
      <p>CyArk was founded by Iraqi-American Ben Kacyra as a way to fight the kind of cultural destruction that was typical of the Taliban and ISIS in Iraq and Afghanistan over the last decades. But as modeling technology has become cheaper and more portable, the company’s mission has changed as well, Ristevski says, with less emphasis on secure data storage and individual projects and more on <a href="https://openheritage3d.org/">open access</a> and education.</p><p>Since its founding, for example, CyArk has stored copies of each site it scans in a secure facility 200 feet underground—the same facility that, according to urban legend, stores Elvis Presley’s master tapes. “We still do that, but it’s a less interesting piece of our work,” Ristevski says. Two years ago, CyArk also began putting its data sets online under a Creative Commons license. “Things that are burrowed away somewhere is one avenue, but now it’s more about sharing and opening up data,” he says.</p><p>Similarly, where CyArk once sought to digitize 500 cultural heritage sites under their own steam, Ristevski says what now excites him is the educational workshops the organization runs around the world. “We’ve seen a lot more adoption of this, especially in the last three or four years,” he says. In early 2020, for example, Ristevski and other CyArk staffers traveled to the South Pacific to <a href="https://www.youtube.com/watch?v=79DfInkneRA&amp;feature=emb_title">give a workshop</a> for monument staff and local Indigenous communities at Rapa Nui, also known as Easter Island. That site, much like Skara Brae, faces continual damage from wind and waves, so CyArk did a set of initial point-cloud models to act as a baseline, allowing for annual monitoring of how each of the island’s enormous stone statues is weathering. Helping local authorities monitor their own site makes it possible to scan all 500 sites on the island, he says, whereas CyArk might only have had time or resources for one or two.</p><p>A technique like point-cloud modeling can also create an opportunity for sorting through and storing many types of information. Notre Dame is a perfect example. “Even if today we are building a lot of data around this physical aspect, we are also building a ‘knowledge cathedral’ at the same time,” De Luca says. For his team, that means building a “digital twin” of the cathedral, a real-time virtual clone of the physical object that records more than just the geometric dimensions of the cathedral before and after the fire. This digital twin also manages the myriad chemistry, physics, art history, archaeology, and engineering data generated by its many restoration projects—from managing the <a href="https://www.pbs.org/wgbh/nova/video/stabilizing-notre-dames-buttresses/">flying buttresses</a> to cataloguing each of the thousands of pieces of tangled, burnt wood that once made up the “forest” in the cathedral’s attic—and makes it available within a few minutes of its collection.</p>
            <figure class="richtext-image full-width"><img alt="Digital model of 2 stone statues" class="richtext-image full-width" height="450" width="800"
            src="https://www.pbs.org/wgbh/nova/media/images/Rob1.width-800.png"/><figcaption><p>Point-cloud images of huge stone statues at Rapa Nui, also known as Easter Island. Image Credit: CyArk</p><div class="credit"></div></figcaption>
            </figure>
            <p></p>
  

  
      <p>Past Skara Brae, even farther north into the cold reaches of the Atlantic ocean, sits Mousa Broch, a 40-foot-tall Iron Age stone tower built around 300 BCE on a bluff overlooking the sea. Even for the few visitors that make it to the Shetland Islands, Mousa Broch is difficult to access, requiring a strenuous hike. But point-cloud modeling has allowed Mirashrafi’s team not just to gather essential records of the building for posterity but also to open the site (or a version of it) to the public.</p><p>As part of their scanning efforts, they’ve translated the point-cloud version of Mousa Broch into a version most computers can handle, through a site called <a href="https://sketchfab.com/HistoricEnvironmentScotland">SketchFab</a> (which Mirashrafi calls the “YouTube of 3D models.”) “Sharing for education and interpretation is something we’re equally interested in,” she says. Flocks of storm petrels roost at Mousa Broch at night, so as an extra immersive touch, the team layered recordings of the seabirds over the model animation. The result: a <a href="https://sketchfab.com/3d-models/mousa-broch-shetland-88a87c90cde8477a87523caa511c1796">rich virtual experience</a> that was previously largely inaccessible.</p><p>In this vein, Mirashrafi says she’s been especially impressed with point-cloud modeling’s potential for storytelling. Being able to digitally recreate a structure or item with such accuracy helps her team fight archaeology’s tendency to strip items of their cultural context. Though the digital can never replace the physical—“When you go out and scan a site, it doesn’t negate the necessity for historians and conservators”—a digital replica is a powerful tool, she says, whether it’s used to help recreate a site before a rock fall or to help the public experience a little bit of new history.</p><p>Through point-cloud models, a lost or destroyed site can be reconstructed; an artifact can be put back virtually where it was originally found. “So often in museum contexts, it’s hand’s off, don’t touch, don’t talk, don’t question,” she says. “These kinds of virtual environments encourage manipulation and questioning,” in a richer way than you might see behind glass.</p>
  

  
      

<div class='cove-video'>
  <iframe allowfullscreen="" class="inline-cove-player" frameborder="0" height="100%" id="partnerPlayer" marginheight="0" marginwidth="0" scrolling="no" src="//player.pbs.org/partnerplayer/ZACs206MAMDaup76pLSohw==/?topbar=false&amp;end=0&amp;endscreen=true&amp;start=0&amp;autoplay=false" width="100%">
</iframe>
</div>


  

  
      <div class="newsletter"></div>
  



Notre Dame Cathedral on fire in April 2019. Image credit: Wandrille de Préville, Wikimedia Commons

<p>Laser-scanning technology can create exceptionally detailed 3D models of cultural sites, bringing them to life online—and helping experts restore them if disaster strikes.</p>

3D models help preserve landmarks like Notre Dame





  
      <p>On Monday, AstraZeneca announced that its coronavirus vaccine is up to 90% effective, according to late-stage trials. It’s also relatively cheap and easy to store, meaning it may become the choice vaccine for developing nations.</p><p>Though the vaccine’s efficacy was 90% in one of the dosing regimens its team tested, its average effectiveness was 70%. A vaccine’s efficacy is measured as the percent reduction in disease incidence among a vaccinated group of people compared to an unvaccinated or placebo group, according to the Canadian Center of Vaccinology. (The average <a href="https://www.pbs.org/wgbh/nova/video/does-the-flu-shot-work/">flu vaccine</a> is about 31-44% effective, <a href="https://www.cdc.gov/flu/vaccines-work/2019-2020.html#anchor_1573061303373">the CDC reports</a>.)</p><p>The team administered different vaccine regimens to different groups: One received two full doses, whereas another received a half dose followed by a full dose. The team expected that two high doses would set off the strongest immune response, Andrew Pollard, director of the Oxford University Vaccine Group and chief investigator for the trial, explained at a news conference. But the opposite occurred.</p>
  

  
      <div class="related"></div>
  

  
      <p>For the subgroup that received two full doses of the AstraZeneca vaccine a month apart, it was only 62% effective. But in the group that was given half a dose followed by a full dose one month later, the vaccine was 90% effective.</p><p>Oxford scientists, who helped develop the new vaccine, are positing that a half dose followed by a full dose may prime the body to create a greater immune response to SARS-CoV-2, the virus that causes COVID-19. But they’re unsure why. The 90% efficacy rate, while comparable to 95% effectiveness reported last week by both <a href="https://www.pbs.org/wgbh/nova/article/pfizer-moderna-covid-vaccines-clinical-trials/">Moderna and Pfizer</a>, was recorded in a group of fewer than 3,000 people. Conversely, Moderna’s trial has involved 30,000 people, half of whom received its vaccine and half a placebo. Pfizer’s trial has enrolled more than 43,000 volunteers, 38,955 of whom have completed its vaccine regimen as of November 16 (with half receiving a vaccine and half a placebo).</p><p>AstraZeneca’s results reported Monday come from trials involving a total of 23,000 people in the U.K. and Brazil, 11,636 of whom were given the vaccine with the remaining receiving a placebo. Researchers said 131 Covid-19 cases were detected during the clinical trials and none of the study participants that fell ill required hospitalization. AstraZeneca has yet to release information on how many of these participants received the vaccine and how many received the placebo.</p><p>Unlike <a href="https://www.pbs.org/wgbh/nova/article/pfizer-moderna-covid-vaccines-clinical-trials/">Pfizer and Moderna’s mRNA vaccines</a>, which use synthetic genetic material to help the body produce one small component of the virus itself that the immune system can learn from—in this case, SARS-CoV-2’s iconic spike protein—the AstraZeneca vaccine uses a weakened version of a common cold virus that’s combined with genetic material for the spike protein, Danica Kirka <a href="https://apnews.com/article/astrazeneca-vaccine-third-cheaper-oxford-c99d26eb2946f6fde45a1edc002ff028">writes for the Associated Press</a>. “After vaccination, the spike protein primes the immune system to attack the virus if it later infects the body.”</p><p></p><p><b><i>Watch to learn more about mRNA vaccine technology:</i></b></p>
  

  
      

<div class='cove-video'>
  <iframe allowfullscreen="" class="inline-cove-player" frameborder="0" height="100%" id="partnerPlayer" marginheight="0" marginwidth="0" scrolling="no" src="//player.pbs.org/partnerplayer/qHbEQK5e0AS8KA8k4_7H0Q==/?topbar=false&amp;end=0&amp;endscreen=true&amp;start=0&amp;autoplay=false" width="100%">
</iframe>
</div>


  

  
      <p>And while Moderna and Pfizer and BioNTech’s vaccines need to be stored at freezing temperatures, this new vaccine remains viable at 36 to 46 F. (Storing vaccines at their required temperature is one of the greatest challenges that developing countries face with routine immunization.)</p><p>“I think these are really exciting results,” Pollard said. “Because the vaccine can be stored at fridge temperatures, it can be distributed around the world using the normal immunization distribution system.”</p><p>It’s also cheaper. Pfizer and BioNTech, as part of their $1.95 billion contract with the federal government under <a href="https://www.hhs.gov/coronavirus/explaining-operation-warp-speed/index.html">Operation Warp Speed</a>, “have set the initial price at $19.50 a dose, which comes to $39 per patient (since each vaccine requires a two-dose regimen),” Katie Jennings <a href="https://www.forbes.com/sites/katiejennings/2020/11/17/how-much-will-a-covid-19-vaccine-cost/?sh=7c14e82f576d">writes for Forbes</a>. Moderna, which received nearly $1 billion from the Biomedical Advanced Research and Development Authority and has a $1.5 billion contract for 100 million doses, says its vaccine will cost approximately $25 a dose or $50 a patient, since it too requires a second dose.</p><p>Conversely, AstraZeneca’s vaccine will cost about $2.50 a dose.</p><p>AstraZeneca has pledged to not make a profit on the vaccine during the pandemic and having reached agreements with governments and health organizations, Kirka reports.</p><p>It plans to have more than 300 million full doses of its vaccine available globally by the end of March 2021. That number could increase by 50%, given the promising results of first administering a half dose to patients, followed by a full dose one month later. The company hopes to produce around 200 million doses a month, AstraZeneca’s Executive Vice President Pam Cheng said during a press event.</p>
  

  
      <div class="ad"></div>
  

  
      <p>The Pfizer, Moderna, and AstraZeneca vaccines will all need to be approved by regulators before they can be widely distributed. “AstraZeneca said it will immediately apply for early approval of the vaccine where possible, and it will seek an emergency use listing from the World Health Organization, so it can make the vaccine available in low-income countries,” Kirka writes.</p><p>Pfizer and Moderna plan to apply for FDA emergency use authorization this month. Moderna stated on November 16 that it expects to be able to ship about 20 million vaccine doses in the U.S. by the end of this year and another 500 million to 1 billion in 2021, if authorized to do so. Pfizer expects to produce up to 50 million vaccine doses in 2020, and 1.3 billion in 2021, if authorized.</p><p>These COVID-19 vaccine rollout plans raise the question: Who should—and ultimately will—get vaccinated the soonest?</p><p>Vaccine supplies will be limited at first, meaning the decisions about who gets those first doses could save tens of thousands of lives, Jill Neimark <a href="https://undark.org/2020/11/18/best-strategy-to-deploy-covid-19-vaccine/">writes for Undark Magazine</a>. “The consensus among most [disease] modelers is that if the main goal is to slash mortality rates, officials must prioritize vaccinating those who are older, and if they want to slow transmission, they must target younger adults,” she writes.</p><p>Many experts agree that the threat of superspreaders must not be ignored. “This is a pandemic defined by clusters,” Christopher Cox <a href="https://www.wired.com/story/covid-19-vaccine-super-spreaders/">writes for WIRED</a>. “Some cause deadly outbreaks in nursing homes, prisons, and meatpacking plants. Others overwhelm families and friend groups. Although the numbers vary from study to study, SARS-CoV-2 seems to follow the 80/20 rule: 80 percent of cases stem from just 20 percent of infected individuals.” Some network theorists believe that social butterflies, who are the most likely to become superspreaders, should be vaccinated first.</p><p>For now, it seems, the first doses of a COVID-19 vaccine will go to health care providers here in the U.S. and in the World Health Organization’s member countries, per its recommendation. But the CDC committee is grappling with a fundamental question, Cox writes: Do doctors first immunize the most vulnerable, and therefore protect individuals, or do they immunize the most social, and therefore reduce transmission and protect the population?</p><p>And then, of course, are the issues of trust and inequity, Neimark writes: “For instance, it’s widely acknowledged that Black people have experienced hospitalization and death at disproportionately high rates compared to White people.” And because of algorithmic bias, a recent study found, White patients are often <a href="https://www.pbs.org/wgbh/nova/article/racial-bias-medical-algorithm-black-patients/">prioritized over Black patients</a> in hospitals, even when Black patients are sicker than their White counterparts. “When ethicists begin to talk about prioritizing Black people for vaccines, it can be perceived as an intent to experiment on them by pushing them to the head of the line,” Neimark writes.</p><p>One thing is sure: Multiple vaccines will be necessary to help bring an end to the pandemic, which has to date sickened more than 12.5 million Americans and nearly 60 million people worldwide. And if there’s any silver lining to the surge of cases in the U.S. and worldwide, Rebecca Robbins <a href="https://www.nytimes.com/2020/11/18/business/covid-pandemic-speeding-vaccines.html?action=click&amp;module=RelatedLinks&amp;pgtype=Article">reports for the New York Times</a>, it’s that the uptick could make results from other closely watched vaccine trials available sooner and with greater statistical power, while also speeding up trials of COVID-19 treatments.</p>
  

  
      <div class="newsletter"></div>
  



Vaccine and band-aid on a tray in a doctor's office. Image credit: SELF Magazine

<p>The Pfizer, Moderna, and AstraZeneca vaccines are at least 90% effective, according to clinical trials. Here’s who may get vaccinated first.</p>

A third Covid-19 vaccine is effective and cheap. What happens next?





  
      <div class="related"></div>
  

  
      <p>Today, Pfizer and BioNTech announced that their new experimental Covid-19 vaccine is 95% effective in preventing infections and causes no serious safety concerns, according to a final analysis of their clinical trial.</p><p>&quot;Efficacy was consistent across age, race and ethnicity demographics. The observed efficacy in adults over 65 years of age was over 94%,&quot; Pfizer and its German partner BioNTech said in a joint statement.</p><p>The news comes just two days after the biotech company Moderna Inc. said its experimental vaccine was 94.5% effective in preventing disease, according to an analysis of its <a href="https://www.fda.gov/patients/drug-development-process/step-3-clinical-research">Phase 3 clinical trial</a>. Last week, Pfizer and BioNTech had announced that their vaccine was more than 90% effective. Both vaccines use <a href="https://www.pbs.org/wgbh/nova/video/rna-coronavirus-vaccine/">new mRNA technology</a>.</p><p>Moderna’s study involved 30,000 volunteers. Half of those volunteers received its coronavirus vaccine twice 28 days apart and the other half received two doses of a placebo on the same schedule.</p><p>“There were 95 instances of Covid-19 illness among the study participants; only five of those cases were in the vaccinated group,” Joe Palca <a href="https://www.npr.org/sections/health-shots/2020/11/16/935239294/modernas-covid-19-vaccine-shines-in-clinical-trial">writes for NPR</a>. “Ninety were in the group receiving the placebo. Of these, there were 11 cases of severe disease. The results indicate the vaccine was inducing the kind of immune response that protects people if they were exposed to the coronavirus.”</p><p>The results for Pfizer and BioNTech’s vaccine also come from interim analyses of a large Phase 3 clinical study, which has not yet been peer reviewed by other scientists. The companies’ trial has enrolled more than 43,000 volunteers in six countries to date, and 38,955 of them have completed its vaccine regimen so far. Pfizer and BioNTech’s regimen also consisted of two vaccine injections or two placebo injections, spaced three weeks apart.</p><p>Pfizer “counted 170 cases of coronavirus infection among volunteers who took part in the trial. It said 162 infections were in people who got placebo, or plain saline shots, while eight cases were in participants who got the actual vaccine,” Maggie Fox and Amanda Sealy <a href="https://www.cnn.com/2020/11/18/health/pfizer-coronavirus-vaccine-safety/index.html">write for CNN</a>.</p><p>Moderna and Pfizer used slightly different protocols to identify Covid-19-positive study participants. Participants in the Moderna study had to have at least two Covid-19 symptoms and a positive test result to be counted as a Covid-19 case. Moderna waited 14 days following the second injection to begin counting cases. Pfizer required one Covid-19 symptom and no test to be counted as a positive case, and it started counting cases at seven days, Palca writes.</p><p>The companies’ vaccines, however, were strikingly similar. A traditional vaccine, like your annual flu shot, uses killed or weakened versions of a virus, or a piece of the virus, to prepare your immune system to recognize and fight off the living virus if you come in contact with it. Conversely, these two new experimental mRNA vaccines attempt to help the body produce one small component of the virus itself that the immune system can learn from. RNA “is kind of an ancient cousin of DNA,” <a href="https://www.pbs.org/wgbh/nova/video/rna-coronavirus-vaccine/">Rhiju Das told NOVA</a> in April. “RNA molecules are the scripts that viruses use and that our human bodies also use to make proteins.” (<a href="https://www.genome.gov/genetics-glossary/messenger-rna">mRNA</a> refers specifically to messenger RNA.)</p>
  

  
      

<div class='cove-video'>
  <iframe allowfullscreen="" class="inline-cove-player" frameborder="0" height="100%" id="partnerPlayer" marginheight="0" marginwidth="0" scrolling="no" src="//player.pbs.org/partnerplayer/qHbEQK5e0AS8KA8k4_7H0Q==/?topbar=false&amp;end=0&amp;endscreen=true&amp;start=0&amp;autoplay=false" width="100%">
</iframe>
</div>


  

  
      <p>The coronavirus’s RNA codes for at least 24 proteins, including the spike protein, which covers its exterior. The virus uses its spike protein to bind to and enter our cells, where it then injects its RNA, hijacking our human cells to make many more copies of the virus.</p><p>“It’s almost like a skeleton key for a lock, opening a portal within human cells that the virus can slip in,” Das told NOVA.</p><p>Both Moderna’s and Pfizer’s mRNA vaccines prompt a person’s cells to produce the SARS-CoV-2’s spike protein, so their immune system can learn to recognize it and develop Covid-19-fighting antibodies without having any contact with the actual virus.</p><p>“Our bodies won’t make a full-fledged infectious virus,” Das said. “They’ll just make a little piece and then learn to recognize it and then get ready to destroy the virus if it then later comes and invades us.”</p><p>Moderna and Pfizer are still gathering safety data that the Food and Drug Administration requires for consideration of an emergency use authorization. This authorization would allow vaccine manufacturers to distribute their vaccines during the pandemic at an earlier date than otherwise possible. “To apply for an emergency use authorization, the FDA requires that half of participants have at least two months of data regarding a Covid-19 vaccine’s safety after they receive the final dose. For Pfizer and BioNTech’s vaccine, that point is expected to come in the third week of November,” Erin Garcia de Jesús <a href="https://www.sciencenews.org/article/coronavirus-covid-19-vaccine-pfizer-effective-early-trial-data">writes for Science News</a>.</p>
  

  
      <div class="ad"></div>
  

  
      <p>Both companies plan to apply for FDA emergency use authorization this month. Moderna stated Monday that it expects to be able to ship about 20 million vaccine doses in the U.S. by the end of this year and another 500 million to 1 billion in 2021, if authorized to do so. Pfizer expects to produce up to 50 million vaccine doses in 2020, and 1.3 billion in 2021, if authorized.</p><p>To prepare to store a hopefully forthcoming coronavirus vaccine, large urban hospitals across the U.S. are rushing to buy expensive ultra-cold freezers. (Last week, Pfizer and BioNTech said that their vaccine needs to be stored at minus 94 F. Conversely, Moderna states that its vaccine can be safely stored in freezers at about 25 F for 30-day storage, “a temperature easily reached by a home refrigerator freezer,” Palca writes. However, safe 6-month storage would require a temperature of minus 4 F, <a href="https://investors.modernatx.com/news-releases/news-release-details/moderna-announces-longer-shelf-life-its-covid-19-vaccine">Moderna stated</a> in a press release.) Most rural hospitals can’t afford ultra-cold freezers, “meaning health workers and residents in those communities may have difficulty getting the shots,” Olivia Goldhill reports for <a href="https://www.statnews.com/2020/11/11/rural-hospitals-cant-afford-freezers-to-store-pfizer-covid19-vaccine/">STAT News</a>.</p><p>Medical experts call the temperature-controlled supply chain of vaccines and other protein-based pharmaceuticals the “cold chain,” because the protein molecules in these products can break down at higher temperatures, rendering them ineffective.</p><p>“Maintaining vaccines continuously at their required temperature is already one of the biggest challenges developing countries face with routine immunization, and this will only be exacerbated with the introduction of a new [coronavirus] vaccine,” Toby Peters <a href="https://www.wired.com/story/a-possible-covid-vaccine-means-its-time-to-fix-cold-chains/">writes for WIRED</a>.</p><p>In a paper published in May in <a href="https://science.sciencemag.org/content/368/6494/948">the journal Science</a>, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, suggested that the U.S. population alone may require <a href="https://www.pbs.org/newshour/politics/watch-fauci-says-u-s-has-many-vaccine-candidates-and-hope-to-have-many-winners">several different vaccines</a> made and distributed by different labs to bring an end to the pandemic, which, according to Johns Hopkins University’s <a href="https://coronavirus.jhu.edu/map.html">Covid-19 dashboard</a>, has so far sickened more than 11.3 million Americans and more than 55.7 million people worldwide.</p>
  

  
      <div class="newsletter"></div>
  



A closeup image of a doctor's hands, vaccine, and patient's arm. Image credit: SELF Magazine

<p>Both vaccines performed excellently in clinical trials. What comes next?</p>

Brand: NOVA Next

Hero Feature

Toxic synthetic 'forever chemicals' are in our water and on our plates

Featured Content

Armenia reckons with climate change and its Soviet past through reforestation

In a swirl of rocks and dust, OSIRIS-REx probe touches an asteroid

Explore Topic: NOVA Next

I’ve been exposed to Covid-19. When should I get tested?

NOVA’s top 5 science stories of 2020

Japan’s Hayabusa2 returns asteroid sample to Earth in “perfect condition”

3D models help preserve landmarks like Notre Dame

A third Covid-19 vaccine is effective and cheap. What happens next?

Pfizer and Moderna Covid vaccines 95% effective in clinical trials

Toxic synthetic 'forever chemicals' are in our water and on our plates