An image of Pōwehi, a supermassive black hole in the galaxy Messier 87. This image, which is the most detailed to date taken of a black hole, uses polarized light to reveal relativistic jets (in yellow and red) extending from Pōwehi. Image Credit: the Event Horizon Telescope Collaboration.

You didn't get sucked into a black hole. Now what?

<p>In March, an international network of scientists called the Event Horizon Team delivered the most detailed photograph of a black hole compiled to date. The supermassive black hole it featured, galaxy Messier 87’s Pōwehi, is 6.5 billion times as massive as the Sun and looks like a vibrant, swirling pool of flames being sucked into a dark center.</p><p>That bright ring outside the black hole—its accretion disc—is actually made up of a spiraling vortex of hot, magnetized matter. “This region itself is five times larger than the size of the black hole,” says Jordy Davelaar, a member of the Event Horizon Team and theoretical astrophysicist at Columbia University. “Though in the sky, it [looks] super tiny.”</p>
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<p>“Tiny” to an astrophysicist, of course, is relative. If you were to orbit Pōwehi’s exact center point at a distance relative to Pluto’s orbit of the Sun, Davelaar explains, you would be within the event horizon, your orbit nowhere near its accretion disc. This means our entire solar system would fit inside this supermassive black hole’s event horizon with room to spare.</p><p>Every black hole captures material that gets too close to its event horizon, a boundary in space marking the limit of the black hole and a point of no return from it. All objects—even beams of light—that cross the event horizon will not be able to get back out. If you were to approach a black hole much smaller than Powehi feet-first, you’d feel the gravitational pull on your feet increasing much more severely than you would on your head, causing you to be stretched thin as a noodle in a process called “spaghettification.” But approach the event horizon of a huge black hole, like that of Pōwehi, and you wouldn’t get stretched: Rather, you’d gently cross the event horizon without any particular sensation at all. “You would not feel any spaghettification,” says Rutuparna Das, an astrophysicist at Harvard &amp; Smithsonian’s Center for Astrophysics.</p>
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<img alt="First-ever image of a black hole" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/A-Consensus.width-990_XaMU9lG.jpg"/>
<figcaption><p>Astrophysicists use radio telescopes, which pick up radio waves emitted by black holes and other objects in space that don’t give off optical light, to hunt for black holes, says Rutuparna Das, who conducts research for NASA’s Chandra X-ray Observatory. Telescopes like Chandra can be used to illuminate and observe material orbiting black holes, making a black hole’s spinning accretion disc appear to glow (as seen in this image of Pōwehi from 2019). Image Credit: Event Horizon Telescope collaboration</p>
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<p>Why would a black hole spaghettify objects in the first place? It’s a result of the black hole’s incredibly dense, gravity pit of a center called the singularity. When there is a difference in the gravitational pull of two points relative to each other, it results in what’s called tidal forces. Such forces—which surround all black holes—also affect us here on Earth. “There are tidal forces from the Moon on the Earth that we see in how our water moves,” but are too small to feel, Davelaar says. Tidal forces of black holes cause spaghettification, but because of the overwhelming mass of a supermassive black hole, you wouldn’t be spaghettified until after you crossed its event horizon. If you were to approach a black hole with a smaller mass, however, you would be <a href="https://gizmodo.com/heres-why-small-black-holes-are-more-dangerous-than-big-1681979641">spaghettified well before</a> reaching its event horizon.</p><p>While you might avoid spaghettification due to Pōwehi’s size, you wouldn’t survive the destructive spin of its accretion disc. “The environment is super lethal,” Davelaar says. Material in the accretion disc “accelerates at such velocity it wouldn’t be pleasant for a human being,” adds Maria Charisi, an astrophysicist at Vanderbilt University. As the accretion disc spins, tidal forces shred the stars and gas clouds caught within it down to their atoms.</p><p>No longer intact, you (now broken down to your atoms) may drift toward Pōwehi’s event horizon before entering its center, where intense gravity destroys material. But first you’d visit Pōwehi’s innermost stable orbit, which looms just outside of the event horizon. The innermost stable orbit is the last place any space material has a chance to escape.</p>
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<p>Not all material in the disc falls into a black hole, says Edo Berger, an astrophysicist at Harvard &amp; Smithsonian’s Center for Astrophysics. It’s like “feeding a baby,” Berger says. Much like an infant may spit out mashed potatoes, a supermassive black hole may hurl from its accretion disc the remnants of its cosmic lunch of stars, dust, and other space matter in beams called relativistic jets, which can extend beyond its accretion disc into outer space.</p><p>The deciding factor of what gets consumed and what gets shot out in a relativistic jet is “whichever side is closest to the hole,” Berger says. If you were orbiting Pōwehi clockwise, the right side of you might meet its demise in the singularity while the left side of your body could be sent flying away from Pōwehi in a jet.</p>
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<figcaption><p>This color composite image of Centaurus A reveals the lobes and jets emanating from the galaxy’s central black hole. It was compiled using images taken by three instruments operating at different wavelengths: Data from LABOCA on APEX are shown in orange, X-ray data from the Chandra X-ray Observatory are shown in blue, and visible light data from the MPG/ESO 2.2 m telescope in La Silla, Chile, show background stars and the galaxy’s characteristic dust lane. Image Credit: ESO/WFI; MPIfR/ESO/APEX/A.Weiss et al.; NASA/CXC/CfA/R.Kraft et al. </p>
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<p>The beam of a supermassive black hole’s relativistic jet can reach so far that it may even extend outside of its galaxy, Charisi says. According to a 2012 observation by the Event Horizon Team, Pōwehi’s jet extends a whopping 5,000 light-years outside of Messier 87, and the material within the jet shoots out in “clumps and knots,” <a href="https://www.nasa.gov/mission_pages/chandra/images/famous-black-hole-has-jet-pushing-cosmic-speed-limit.html">NASA wrote</a> in a January 2020 press release. NASA’s Chandra X-ray Observatory, a space telescope that detects X-ray emissions from very hot regions in the universe, discovered that Pōwehi’s jet is moving at a staggering 99% the speed of light. But as a black hole’s relativistic jet tears through the cosmos, the space material it crosses, including gas clouds, slow it down, Charisi says.</p><p>“At some point [the jet] will decelerate,” she says. “If you look at radio galaxies, you see these pencil-thin beams where the jet is accelerating, and then you see these blobs around them, where they have lost velocity.” The blobs at the decelerated ends of a relativistic jet slowly dissipate into space, says Charisi, creating a dumbbell shape around the galaxy, like that seen in images of radio galaxy Centaurus A.</p><p>Once your atoms arrive in the blob of Pōwehi’s relativistic jet, millions of years would have passed since you first ventured into its accretion disc. Though you avoided being swallowed up by the black hole, now, 5,000 light-years away from Pōwehi, your atomic remnants slowly drift apart in space. “Eventually [they] will dissipate,” Charisi says, though astrophysicists are not yet sure how long that may take.</p>
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<p data-block-key="g1lkv">Not everything that crosses a supermassive black hole’s accretion disc gets spaghettified, astrophysicists say.</p>

The second-ever direct image of a black hole features Sagittarius A*, the supermassive black hole at the center of our galaxy. Image Credit: Event Horizon Telescope collaboration

Scientists capture first-ever image of our galaxy’s supermassive black hole

<p>On Thursday morning, an international team of astrophysicists and other researchers released the world’s first image of the supermassive black hole at the center of our galaxy, 27,000 light-years from Earth. </p><p>The event marks “the dawn of a new era of black hole physics,” the team<a href="https://twitter.com/ehtelescope/status/1524737908892049408"> announced on Twitter</a>.</p><p>More than 4 million times the mass of our sun, the black hole, named Sagittarius A* (or Sgr A*, pronounced “sadge ay star,” for short) is so dense and massive that no light can escape its gravity. The visible light in the new image comes from bright stars, gas, and other space matter swarming around the black hole itself.</p>
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<p>The image is the first visual evidence of Sgr A*’s existence; the black hole was previously only indirectly confirmed by observations of stars in orbit around it. The image comes from the Event Horizon Telescope’s (EHT) international consortium. A group of more than 300 scientists helped with the effort to capture it, “compiling information from radio observatories around the world,” Bill Chappell <a href="https://www.npr.org/2022/05/12/1098472567/image-black-hole-milky-way">reports for NPR</a>. (The EHT, named for the event horizon, or “point of no return” from a black hole, consists of eight radio telescopes scattered across the globe.)</p><p>In 2019, the EHT team compiled an <a href="https://www.pbs.org/wgbh/nova/article/first-black-hole-image/">image of Pōwehi</a>, a supermassive black hole 55 million light-years away in the galaxy Messier 87. Similar in appearance to Sgr A* but much more massive, Pōwehi is 6.5 billion times the mass of our sun.</p><p>The much smaller Sgr A* proved difficult for scientists to visually capture: It’s a “dynamic environment” full of burbling and gurgling, Feryal Özel, a professor of astronomy and physics at the University of Arizona, told NPR. And the necessity to look through both the Earth’s atmosphere, gas clouds, and interstellar dust near the Milky Way’s center added to the challenge, Özel said. “It took several years to refine our image and confirm what we had, but we prevailed," Özel told NPR. And, despite its meager distance from Earth compared to Pōwehi, Sgr A* is far enough away to appear “to us to have about the same size in the sky as a donut on the Moon,” the EHT team stated <a href="https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy">in a press release.</a></p><p>Hot gas whirling around Sgr A* at nearly the speed of light made capturing an image of this black hole considerably more difficult than Pōwehi, the EHT team said in the press release. “The brightness and pattern of the gas around Sgr A* was changing rapidly as the EHT was observing it,” EHT scientist Chi-Kwan Chan said in the press release.</p>
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<p>Images of Pōwehi captured by astronomers across the EHT were visually similar to one another, allowing scientists to compile a sharp composite image of Messier 87’s black hole. “That was not the case for Sgr A*,” the EHT team said in the press release. But despite these initial inconsistencies, the scientists were eventually able to compile an image of Sgr A*.</p><p>Now, having images of such differently sized black holes provides a better look into the behavior of swirling gas around supermassive black holes, a phenomenon that’s not yet fully understood, but thought to play a key role in how galaxies, like our own, came to be. "Now we can study the differences between these two supermassive black holes to gain valuable new clues about how this important process works," EHT scientist Keiichi Asada said in the press release. </p>
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<p data-block-key="qta1u">The Event Horizon Telescope team has captured the first image of Sagittarius A*, the black hole at the center of the Milky Way. </p>

A giant pink circle with a bright center and "spokes" out to its outer edges against a black sky

The Cartwheel galaxy (right) was formed as the result of a high-speed collision about 400 million years ago. This composite image brings together observations from JWST's infrared instruments. Image Credit: NASA, ESA, CSA, STScI

The top science stories of 2022

<p>As of 2022, you share this planet with 8 billion people (and about <a href="https://www.wgbh.org/news/science-and-technology/2022/09/21/the-number-of-ants-on-earth-has-a-mass-greater-than-all-birds-and-mammals-combined">20 quadrillion ants</a>). </p><p>It’s not just population growth that made this year remarkable. From January to December, scientists have launched revolutionary space missions, wrangled new viral outbreaks, discovered old DNA, and even taken a step towards <a href="https://www.pbs.org/wgbh/nova/video/scientists-make-breakthrough-in-nuclear-fusion/">harnessing nuclear fusion</a>. Explore the science that made headlines throughout 2022.</p>
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<h3><b>Tonga volcano eruption</b></h3><p>Just off the island nation of Tonga in the South Pacific, a mostly underwater volcano called Hunga Tonga-Hunga Ha'apai quite literally rocked the world when it erupted on January 15.</p><p>Hunga Tonga-Hunga Ha'apai’s eruption was one of the <a href="https://www.quantamagazine.org/scientists-unravel-how-the-tonga-volcano-caused-worldwide-tsunamis-20220413/">most powerful on record</a>—hundreds of times more powerful than the atomic bomb dropped on Hiroshima, <a href="https://earthobservatory.nasa.gov/images/149367/dramatic-changes-at-hunga-tonga-hunga-haapai">NASA reported</a>, and the largest explosion of any kind in the <a href="https://www.cnn.com/2022/05/12/asia/tonga-eruption-biggest-in-more-a-century-scn/index.html">last 140 years</a>. Its roar was heard nearly 6,000 miles away in Alaska, and the eruption triggered tsunamis that reached Tonga, nearby Fiji, and far-off locations like Japan, Russia, Peru, and the United States. The volcano’s <a href="https://www.pbs.org/wgbh/nova/article/hunga-tonga-volcano-eruption-education/">unique position</a> may help explain why this particular eruption created such a violent shockwave. But the full implications of the explosion for future volcanic events <a href="https://www.jpl.nasa.gov/news/tonga-eruption-blasted-unprecedented-amount-of-water-into-stratosphere">are still being studied.</a></p>
<h3><b>Ernest Shackleton's ship Endurance is found after 106 years</b></h3><p>In December 1914, British explorer Ernest Shackleton led a crew of 27 men aboard two ships, Endurance and Aurora, on an expedition to Antarctica. The goal was to complete the first land crossing of the Antarctic continent. But in January 1915, the Endurance became trapped in the ice of the Weddell Sea before reaching land.</p><p>For nine months, Shackleton and his crew tried to break the ship free. But their efforts were unsuccessful, and Endurance was gradually crushed by the shifting ice. In October 1915, Shackleton ordered his crew to abandon the ship, and a month later Endurance slipped beneath the surface, not to be seen again. Until this year.</p>
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<img alt="Black and white photo of a three-masted ship trapped in ice, with huge ice chunks in foreground" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/Shackeltons_Endurance.width-990.jpg"/>
<figcaption><p>A distant view of the Endurance trapped in an ice floe. Image Credit: James Francis Hurley via National Maritime Museum, Wikimedia Commons</p>
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<p>On February 5, an expedition called Endurance22 set off from Cape Town, South Africa, in search of Shackleton’s long-lost ship. And on March 5, some 106 years after it was lost, Endurance was found. Using sonar, the team spotted the sunken ship just four miles south of where the original captain, Frank Worsley, had said it was in 1915, <a href="https://www.npr.org/2022/03/09/1085432575/endurance-ship-found-ernest-shackleton">NPR reported</a>. Shockingly well-preserved, Endurance had “hardly anything living on it,” and some of its original paint still intact, Endurance22 expedition leader John Shears told NPR. “It’s as if it sank only yesterday,” Shears said. The Endurance will stay in the Weddell Sea, protected as a historical site under the Antarctic Treaty.</p>
<h3><b>First images from James Webb Space Telescope</b></h3><p>Of NASA's many successful endeavors this year, the images taken by the agency's <a href="https://www.pbs.org/wgbh/nova/video/ultimate-space-telescope/">James Webb Space Telescope</a> (JWST) are perhaps the most awe-inspiring (Have you seen JWST's image of <a href="https://www.nasa.gov/feature/goddard/2022/new-webb-image-captures-clearest-view-of-neptune-s-rings-in-decades">Neptune's rings</a>? Tell me that doesn’t leave you awestruck.) </p><p>JWST launched at the end of 2021 and gradually unfolded, <a href="https://www.pbs.org/wgbh/nova/video/how-scientists-created-the-james-webb-telescopes-first-test-image/">aligning 18 segments</a> of its massive, gilded mirror before getting to work. A month after its launch, the telescope was already a million miles from Earth. And in July, NASA began to unveil <a href="https://www.pbs.org/wgbh/nova/article/james-webb-space-telescope-first-images-nasa/">stunning images</a> of stars and faraway nebulas in greater clarity than its predecessor, Hubble. JWST has also managed to capture galaxies <a href="https://blogs.nasa.gov/webb/2022/12/09/nasas-webb-reaches-new-milestone-in-quest-for-distant-galaxies/">never before seen</a> by scientists, breaking the record for the most distant galaxy ever detected.</p>
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<figcaption><p>"Cosmic Cliffs" in the Carina Nebula, as captured by the James Webb Space Telescope. Image Credit: NASA, ESA, CSA, STScI </p>
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<p>In the coming years, the telescope's data will help scientists understand the evolution of stars and planets, since its infrared instruments can peer through dense dust clouds where star and planet formation begins. "The great thing, really, is that this is just the beginning," Stefanie Milam, deputy project scientist on JWST, <a href="https://www.youtube.com/watch?v=kOiGZZ9LU0I&amp;t=143s">told NOVA</a>. "We'll be able to go much, much deeper, and this telescope is going to do what we designed it to do."</p>
<h3><b>Mpox (monkeypox) outbreak</b></h3><p>Mpox, previously referred to as monkeypox, emerged in the U.S. and several other countries where it is not endemic in May. Although the disease—which presents as a painful rash, followed by flu-like symptoms—was first identified in humans in 1970, mpox was fairly unknown to the American public before this year's outbreak. Mpox spread quickly and peaked in early August, with hundreds of cases being reported per day. Around that time, the Department of Health and Human Services declared the disease a public health emergency and authorized the emergency use of mpox vaccines. </p><p>Data suggest that mpox transmission most often occurs through sexual activity or contact with open wounds or mucous membranes, like the eyes and mouth. While anyone can transmit the disease, there was a prevalence in cases among men who have sex with men (MSM). Many public health campaigns encouraged MSM in particular to get vaccinated, and as of this month, 1.1 million people have been vaccinated against mpox in the U.S.</p><p>By late September 2022, <a href="https://www.npr.org/sections/health-shots/2022/08/26/1119659681/early-signs-suggest-monkeypox-may-be-slowing-in-the-u-s">NPR reported</a> that New York City, San Francisco, Houston, and Chicago—all cities with high rates of infection—had begun to see a decline in cases, though not particularly correlated with vaccination rates. The CDC announced in a November report a highly confident assessment that “the overall incidence of monkeypox in the United States is declining.” And in December, the Department of Health and Human Services announced mpox will not be renewed as a public health emergency in 2023.</p>
<h3><b>DART Mission deflects an asteroid</b></h3><p>In 2021, <a href="https://www.pbs.org/wgbh/nova/article/nasa-dart-deflect-hazardous-asteroid-didymos/">NASA launched</a> its Double Asteroid Redirection Test (DART) spacecraft on a mission to test whether scientists could possibly deflect asteroids at risk of colliding with Earth.</p>
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<p>In the first-ever “full scale planetary defense test,” the DART spacecraft set out to knock Dimorphos—a 525-foot asteroid “moonlet” that circles a larger asteroid called Didymos—off track. The spacecraft <a href="https://www.pbs.org/wgbh/nova/article/nasa-dart-asteroid-impact/">slammed into its target</a> in September 2022, but it wasn’t until October that scientists determined that the DART mission was, in fact, a smashing success. <a href="https://www.pbs.org/wgbh/nova/video/watch-dart-spacecraft-smash-into-asteroid/">The spacecraft’s impact</a> nudged the moon closer to Didymos, shortening its nearly 12-hour orbital period by 32 minutes, <a href="https://www.science.org/content/article/nasa-test-mission-successfully-deflects-asteroid">Science reported</a>. While neither Didymos nor Dimorphos pose any risk to Earth, DART is proof that if Earth were to be threatened by an asteroid, humans may actually be able to something about it.</p>
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<h3><b>Dropping water levels reveal dinosaur tracks, Nazi warships, human remains and more</b></h3><p>The blistering summer of 2022 saw drought from Asia to Europe to North America. And while people may have anticipated a water shortage, few could predict what would be revealed when water levels dropped. </p><p>Spotting dinosaur tracks in Texas’ Dinosaur State Valley Park may not seem surprising. But scientists and park rangers were fascinated to find sets of tracks usually obscured by water suddenly exposed when the park’s Paluxy River dried up <a href="https://www.smithsonianmag.com/smart-news/drought-exposes-dinosaur-tracks-in-texas-180980647/">in August</a>. The footprints, estimated to be 113 million years old, were left deep in the sediment by the carnivorous <i>Acrocanthosaurus,</i> a two-legged dinosaur that weighed up to 7 tons and stood around 15 feet tall. </p><p>Just 1,200 miles away in Nevada, Lake Mead revealed its own <a href="https://www.cnn.com/interactive/2022/12/us/lake-mead-drought-shoreline-discoveries-climate-ctpr/">hidden secrets</a>. Along with long-sunken boats, a total of six sets of human remains—one of which was discovered <a href="https://www.npr.org/2022/05/02/1096049180/a-barrel-containing-a-body-was-exposed-as-the-level-of-nevadas-lake-mead-drops">inside a barrel</a>—were found as the lake’s levels dropped. This year, Lake Mead hit its lowest levels since 1937, continuing a 22-year long downward trend, <a href="https://earthobservatory.nasa.gov/images/150111/lake-mead-keeps-dropping">NASA reports</a>. “There’s no telling what we’ll find in Lake Mead,” former Las Vegas mayor and defense attorney Oscar Goodman said in May. “It’s not a bad place to dump a body,” he added, <a href="https://www.pbs.org/newshour/nation/officials-prep-for-gruesome-surprises-as-las-vegas-lake-slowly-dries-up">according to PBS NewsHour</a>.</p>
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<figcaption><p>A once-submerged speedboat juts out from the dry lakebed of Lake Mead in June 2022. Image Credit: James Marvin Phelps, Flickr</p>
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<p>Regional drought and a heatwave in southwestern China led to a rapid water level drop in the country’s massive Yangtze River, revealing a small island and three previously submerged Buddhist statues. The statues are thought to be 600 years old. While the artifacts are exciting, this historic drought—and those expected in summers to come—threatens the livelihood of some 400 million people who depend on the Yangtze River for water.</p><p>But the largest, and perhaps the most dangerous, of these drought discoveries was in Europe. This summer, the Danube River was at its lowest levels in almost a century. Out from the shrinking waters along eastern Serbia emerged dozens of sunken German WWII ships, each covered in tons of ammunition and explosives. The explosives on the ships pose a major ecological and safety risk to the fishing and coal shipping industries operating within the Danube, <a href="https://www.reuters.com/world/europe/low-water-levels-danube-reveal-sunken-ww2-german-warships-2022-08-19/">Reuters reported</a>.<br/><br/>This summer’s drought, and the strange items it brought to light, foreshadow a larger problem to come with climate change. And in colder climes, melting permafrost is also revealing long-unseen entities, though <a href="https://www.smithsonianmag.com/smart-news/scientists-revive-48500-year-old-virus-setting-world-record-180981208/">not all of them</a> are as exciting as dinosaur tracks.</p>
<h3><b>Artemis 1 kicks off a new lunar program </b></h3><p>This year, NASA's much-anticipated <a href="https://www.pbs.org/wgbh/nova/article/artemis-launch-nasa-sls-orion-moon/">Artemis I mission finally took off</a>. Following months of postponements, fuel leaks, and hurricanes, NASA launched the world's most powerful rocket from the Kennedy Space Center on November 16. Artemis I is the first mission in the Artemis program, which aims to put a crew on the Moon. The inaugural mission, which was uncrewed, was intended to test the massive SLS rocket and the Orion crew capsule. </p><p>Once launched, Orion spent 25.5 days zooming well past the Moon and looping back to Earth. The spacecraft <a href="https://www.pbs.org/wgbh/nova/article/artemis-launch-nasa-sls-orion-moon/">splashed down</a> in the Pacific Ocean on December 11. Now begins NASA's post-flight analysis, which will help reveal just what’s possible in <a href="https://www.pbs.org/wgbh/nova/video/why-nasa-is-going-back-to-the-moon/">this new chapter</a> of space exploration.</p>
<h3><b>Oldest DNA ever found</b></h3><p>Last but not least came a breakthrough just before the end of year. On December 7, scientists announced the remarkable discovery of <a href="https://youtu.be/JS0Cn-bDuKs">the oldest DNA to date</a>. The DNA, retrieved from the sediment cores at the northern edge of Greenland, is a whopping 2 million years old. It reveals stunning information about the plants and animals that once inhabited the Arctic, which was once a lush, green landscape. </p><p>The finding, experts say, could not only <a href="https://www.pbs.org/wgbh/nova/article/oldest-dna-study-nature/">revolutionize paleontology</a>, opening new windows onto ancient worlds, but also help us better understand how species adapted to a warming world in the past. “It's as though we really do have a time machine in a way that we never expected,” said Ross MacPhee, senior curator at the American Museum of Natural History.</p><h4>OLDEST DNA EVER FOUND REVEALS SECRETS OF THE ANCIENT ARCTIC:</h4>
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<p data-block-key="ie61a">NASA nudges an asteroid, weird things emerge from water, and scientists tackle a new epidemic.</p>

Red hot chili peppers, and other hot peppers within the Capsicum genus, get their heat from the chemical capsaicin. Image credit: Austin Kirk, Flickr

From jumping horses to jalapeños: the science of spicy peppers

<p>A few months after competing in the 2008 Summer Olympics in Beijing, Norweigian horseback rider Tony André Hansen was stripped of his bronze medal. His horse Camiro had failed a drug test during the Games, testing positive for capsaicin. The International Equestrian Federation <a href="https://www.nytimes.com/2008/08/22/sports/olympics/22doping.html">dismissed the pair</a>, along with three other showjumping riders and horses, from the competition. </p><p>Hansen has not competed in the show ring since.</p><p>Capsaicin is the chemical responsible for the “heat” in chile peppers. Like many over-the-counter muscle rubs—think “IcyHot”—capsaicin can bring on both tingling sensitivity and numbness.</p>
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<p>When applied as a <a href="https://www.reuters.com/article/us-olympics-equestrian-doping/norway-bronze-medalist-suspended-idUSPEK303420080821">paste or lotion to horses’ forelegs</a>, capsaicin can cause a burning sensation that would be exacerbated by knocking against the rails of a jump. If a showjumping horse lifts its legs higher, it avoids the potentially irritating touch of a fence—and its rider avoids incurring penalties. But capsaicin can also soothe aches and pains by temporarily <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006555/">deactivating the nerve endings</a> where it’s applied. An exhausted horse with numbed nerves will perform better than an equally tired one that can feel the full pain of its aching muscles, according to the <a href="https://aaep.org/horsehealth/lameness-and-poor-performance-sport-horse-eventing">American Association of Equine Practitioners</a>, which is why capsaicin is banned from equestrian competitions to this day. </p><p>“Capsaicin binds to the TRPV-1 receptor—a pain receptor present all over our bodies,” says Ivette Guzmán, a horticulturist and member of the Chile Pepper Institute of New Mexico State University. If a horse is sore, “applying capsaicin binds up those pain receptors,” she says. A horse may feel a little bit of heat from topical capsaicin, but “they won’t feel the pain,” Guzmán explains. “It works on us, too.”</p><p>Just as horses experience a numbing feeling from a topical application of capsaicin, your tongue will tingle when you chew a hot pepper. This numbing sensation is often coupled with a burning one that’s enjoyed by spicy food-lovers around the world: Whether eating centuries-old cuisines like <a href="https://www.theatlantic.com/health/archive/2019/04/why-we-call-indian-dishes-curry-colonial-history/586828/">Indian curry</a> or saucy chicken wings on the popular YouTube series “Hot Ones,” human beings have subjected themselves to the uncomfortable chemistry of capsaicin <a href="http://sitn.hms.harvard.edu/flash/2012/issue131b/">for millennia</a>.</p><h3>The need for heat</h3><p>Pepper species native to the Americas fall within the genus <i>Capsicum</i>. Some <i>Capsicum</i> peppers, like the mild bell pepper, have no capsaicin at all. Others, like the jalapeño and habanero pepper—popular additions to dishes requiring some extra “heat”—do have the chemical. (A few <i>Capsicum</i> peppers, including the incredibly-hot ghost pepper, were developed in South Asia by hybridizing varieties from the Americas.)</p><p>“A lot of people mistakenly think the seeds are what hold the spice,” Guzmán says. But “capsaicin is found in the part of the fruit called the placenta: the membrane that holds onto the seeds.”</p><p>But spicy food doesn’t have to be hot to convey heat. In fact, capsaicin doesn’t physically burn your tongue and innards at all. When your body processes capsaicin, your nervous system sends out a response that activates your senses for touch and temperature. The same receptors responsible for blocking topical pain send signals to your brain that you’re being burned when you eat something spicy. And here’s the kick: Capsaicin alters the sensitivity of the pain receptors in your mouth, effectively lowering the temperature at which you feel burning pain. This is why jalapeño sauce feels burning hot even after being refrigerated.</p><p>“These [receptors] work really well when they detect the correct stimulus,” says Joanna Buckley, a chemist at the University of Sheffield in England. “They respond to anything over 43 C (109 F). So if you have a hot cup of tea, this receptor will work correctly and tell you, ‘Oh, your tea’s a bit hot.’” </p><p>The problem is, Buckley adds, these heat-sensing receptors are also triggered by a class of compounds called vanilloids. Capsaicin is one of them.</p>
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<p></p><p>Chemically, capsaicin is corrosive (like hydrogen peroxide), acutely toxic (like chlorine), and irritating (like ammonia). And its irritant qualities won’t just fire up your mouth: Capsaicin can have a similar effect on other mucous membranes. If you’ve ever chopped peppers and then accidentally touched your eye, you understand how irritating this compound can be. </p><p>So why do some people enjoy—and even get a thrill out of—eating a fruit with such a kick?</p><p>“We get interviewed often by chiliheads,” Guzmán says. “I’m Mexican. I grew up eating jalapeños, I grew up eating really spicy food, and I understand that there are other chemicals in [peppers] that are medicinal. But when it comes to chiliheads, I think they’re fascinated by the chemistry of capsaicin and how it makes you feel something you’ve never felt before. It gives you a euphoria.” </p><p>Measuring that euphoria depends on the Scoville scale.</p><h3>Let’s talk Scovilles</h3><p>Named for American pharmacist Wilbur Scoville, <a href="https://www.vox.com/2016/1/22/10810564/wilbur-scoville-google-doodle">the Scoville scale</a> ranks the pungency of chile peppers based on the concentration of capsaicin in the pepper. It’s this concentration that determines how our bodies will react to peppers; while small amounts of capsaicin fall within the “spicy chicken dinner” category, stronger concentrations spell out “weapon-grade pepper spray.” </p><p>In the early 1900s, Scoville, who was working as a chemist at the time, attempted to test out people’s relative capsaicin tolerance. He recruited five human subjects to taste-test mixtures of dried pepper and sugar water and had them report how hot they found each mixture to be. The basis of his heat scale is the amount of sugar water needed to dilute the mixture enough for the majority of his subjects to no longer feel the heat. </p><p>These days, a technique called high-performance liquid chromatography is used to determine exactly how much capsaicin a pepper contains in parts per million, and multiplying the result by 16 converts it to <a href="https://www.smithsonianmag.com/arts-culture/how-hot-is-that-pepper-how-scientists-measure-spiciness-884380/">Scoville Heat Units (SHUs)</a>.</p>
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<p>The highest level of naturally occuring capsaicin is in the Carolina Reaper, the hottest pepper in the world. Its creator, chile pepper grower Ed Currie, bred the pepper by taking one uniquely spicy <a href="https://www.palmettobluff.com/discover/fear-the-reaper">habanero</a> grown on the La Soufrière volcano on Saint Vincent in the Caribbean and crossing it with a Naga Viper pepper, which was developed in the United Kingdom from peppers hailing from the Caribbean and South Asia. The hottest single Carolina Reaper ever to be harvested rang in at 2.2 million SHU, meaning that more than a tenth of the pepper was pure capsaicin.</p><p>High amounts of capsaicin, like those found in the Carolina Reaper, can cause injury. “Capsaicin is a really potent chemical. If you have too much of it, it can be toxic,” Buckley says. “It’s the thing that’s used in pepper spray. We’ve all seen images of people who have been pepper sprayed. Their eyes are swollen up, they’re crying, they can’t see…so it’s incredibly important to know how to handle capsaicin” safely, she says.</p><h3>Your body’s battle against spice</h3><p>If you don’t welcome spicy burns, there’s a way to neutralize the compound’s effects: dairy. “Capsaicin is an oil and it is insoluble in cold water,” Buckley says. Though it’s somewhat soluble in alcohol, like beer, Buckley explains, capsaicin is best dissolved by another oil. “You need to find something that’s fatty to dissolve the capsaicin,” she says. “That’s why the best thing to drink is milk.” </p><p>Although spicy food is sometimes associated with stomach problems—Currie, who not only created the Carolina Reaper but also eats one every day, still <a href="https://www.latimes.com/nation/la-na-reaper-pepper-20141127-story.html#">experiences severe stomach cramps</a>—there is no direct evidence that spicy food causes belly cramps or nausea. The perceived pain, Guzmán explains, may just be a side effect of your gut membranes being irritated. While a 2016 study showed capsaicin can cause those with abdominal disorders to experience <a href="https://pubmed.ncbi.nlm.nih.gov/27094759/">flare-ups in their symptoms,</a> the same can be said for <a href="https://www.pbs.org/wgbh/nova/article/unless-you-have-celiac-disease-gluten-sensitivity-is-probably-just-in-your-head/">too much bread</a>, a famously unspicy food.</p><p>But there are always worst-case scenarios.</p>
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<img alt="Trinidad scorpion pepper" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/Trinidad_Scorpion_Pepper.width-990_7SVn9Gn.jpg"/>
<figcaption><p>A Trinidad moruga scorpion pepper, which is currently the second hottest pepper in the world to the Carolina reaper. Image credit: John Vonderlin, Flickr</p>
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<p>More than 150 different varieties of chile grow in a garden at New Mexico State University’s Chile Pepper Institute. “One year we had a group of students we were doing a tour with in the garden. And one student thought it would be funny if he bit a tiny piece off a Trinidad Scorpion pepper,” Guzmán says. “He did that, and he threw up in the garden, and he passed out, and we had to carry him to a shaded area under some trees.” </p><p>Because capsaicin is a toxin, Guzmán explains, the human body’s first response to an excess of it is to flush it out. (In the student’s case, by vomiting.) </p><p>In 2018, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5893965/">National Institutes of Health reported</a> that a previously healthy 34-year-old man was admitted to the hospital with “thunderclap headaches”—sudden, severe head pain accompanied by fever, blurred vision, and even seizures—after eating a Carolina Reaper whole. Doctors treated him by flushing the capsaicin out of his body, which, like many chemical compounds in large amounts, can be dangerous. </p><p>Of course, Olympic equestrian Tony André Hansen’s story shows that even a small amount of this complex compound can be damaging (and in some cases, even career-ruining). It just depends on where—or upon whom—the capsaicin ends up.</p>
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<p>Discover capsaicin, the active ingredient in chile peppers. (If you can take the heat.)</p>

A brood X cicada photgraphed in New Jersey in 2004. Image Credit: Pmjacoby, Wikimedia Commons

NOVA's top 5 science stories of 2021

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<p>As 2021 began, scientists, along with the rest of us, confronted many of the same issues that dominated 2020: the COVID-19 pandemic, climate change, and the continued disruption of school and work. But unlike last year, when scientific progress was hindered by shutdowns and isolation, this year marked new successes in medicine, climate science, and astronomy. With the development and distribution of coronavirus vaccines and boosters, people were able to emerge and come closer together. (And in spring, a cohort of insects also emerged and came close to people living in the mid-Atlantic region.)</p><p>2021 was also a year of learning. We have a better understanding of the coronavirus and its variants, and are also now armed with vaccines and pills to protect against illness. Scientists delivered new climate information and recommendations for curbing the effects of climate change on the planet. And scientific breakthroughs even had some out-of-this-world results: Just ask the civilians who flew into space. As we say goodbye to 2021, here’s a look back at some of the biggest science stories of the year:</p>
<h3><b>COVID-19 vaccine advancements and campaigns</b>—<b>for humans</b> <b><i>and</i></b> <b>animals</b></h3><p>On December 20, Omicron overtook Delta as the most common coronavirus variant circulating in the U.S., now responsible for more than 70% of infections in the country, according to CDC data. Epidemiologists and other scientists around the world are parsing the potential dangers of the new variant, whose transmissibility has been <a href="https://twitter.com/DrTomFrieden/status/1473127267392016386">compared by doctors</a> to that of the highly contagious measles virus. Already, Pfizer and Moderna, whose vaccines have been used most in the U.S.’s coronavirus vaccination campaign, have released early data showing the effectiveness of their booster shots <a href="https://www.nbcchicago.com/news/coronavirus/booster-shots-and-omicron-is-moderna-or-pfizer-performing-better-heres-the-data-so-far/2711734/">against Omicron</a>. Pfizer’s latest development, an antiviral pill called Paxlovid, also hit the market this month. The pill—which works as a protease inhibitor, blocking the virus’s ability to replicate in the body—is currently in limited supply, but with a reported <a href="https://www.vox.com/future-perfect/22841852/covid-drugs-antibodies-fluvoxamine-molnupiravir-paxlovid">88% efficacy</a> in preventing hospitalization of those sick with COVID-19, it appears to be a promising treatment for the ill as we enter another year of the pandemic, and the potential future where COVID-19 <a href="https://www.wsj.com/articles/will-covid-19-become-endemic-11636222687">is endemic</a>.</p><p>The rollout of boosters is another big milestone in the coronavirus pandemic, first marked by the development and distribution of highly effective vaccines. <a href="https://covid.cdc.gov/covid-data-tracker/index.html#vaccinations_vacc-total-admin-rate-total">According to CDC data</a>, more than 200 million people are fully vaccinated against COVID-19 in the U.S., with more than 67 million having received a booster dose. Even some <a href="https://www.pbs.org/wgbh/nova/article/oakland-zoo-animal-covid-vaccine/">zoo animals</a>, particularly mammal species that are <a href="https://www.pbs.org/wgbh/nova/article/mink-covid-virus-mutation/">able to contract</a> and spread the virus, were vaccinated against COVID-19</p>
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<img alt="Person injects vaccine into an arm" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/Chelsea_Vaxx.width-990_sa4Z3qc.jpg"/>
<figcaption><p>A man receives a coronavirus vaccine at Mass General Brigham's mobile clinic in Chelsea, Mass. Image Credit: Arlo Pérez Esquivel, WGBH</p>
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<p>Taking religious- or history-related vaccine hesitancy into account, many vaccination campaigns targeted particularly vulnerable populations. For example, Chelsea, Massachusetts, a primarily Hispanic city that in 2020 had the highest infection rate in the state, tapped its healthcare providers, religious leaders, and public health officials to lead a vaccination campaign that would best reach community members. As of today, <a href="https://www.chelseama.gov/COVID">85% of its eligible population</a> is vaccinated against COVID-19. </p><p>Nationwide, Native American communities carried a burden of disease unlike any other: As of November 2021, American Indians and Alaskan Natives had 1.6 times the coronavirus infection rate, more than three times the hospitalization rate, and a more than <a href="https://www.cdc.gov/coronavirus/2019-ncov/covid-data/investigations-discovery/hospitalization-death-by-race-ethnicity.html">twice the mortality rate</a> of white Americans. Despite limited healthcare access for Native Americans living in urban communities, successful vaccination campaigns, many of which centered Indigenous values of keeping family members and the larger community safe, helped Native Americans reach the <a href="https://www.pbs.org/wgbh/nova/article/native-americans-highest-covid-vaccination-rate-us/">highest COVID-19 vaccination rate</a> in the country back in July. </p><p>Vaccination campaigns have had varied success worldwide. As some places—like the U.K. and Israel, both of which have higher vaccination rates than the U.S.—receive boosters, others, including the majority of <a href="https://www.nytimes.com/interactive/2021/world/covid-vaccinations-tracker.html">the African continent</a>, still face lower access to vaccines. The <a href="https://www.who.int/campaigns/vaccine-equity">World Health Organization</a>, which advocates for equitable vaccine access and set a target for all countries to vaccinate 10% of their populations by the end of September, has reported on this problem and a potential solution—especially in the face of new coronavirus variants like Omicron.</p>
<h3><b>Space tourism and Mars exploration</b></h3><p>A concept once limited to science fiction, civilian space travel quite literally took off in 2021. Blue Origin, a private space company owned by multibillionaire Jeff Bezos, launched several American celebrities, including actor <a href="https://www.npr.org/2021/10/13/1045377132/william-shatner-star-trek-captain-kirk-blue-origin-space-flight">William Shatner</a> and former athlete <a href="https://www.space.com/news/live/blue-origin-michael-strahan-launch-updates">Michael Strahan</a>, into suborbital spaceflight. These flights, however, were not courtesy of Bezos: The approximately <a href="https://www.cnet.com/news/tom-hanks-says-he-didnt-want-to-pay-28m-for-blue-origin-space-flight/">$28 million price tag</a> turned off actor Tom Hanks, who, despite playing an astronaut in the 1995 film Apollo 13, had no interest in becoming one for such a cost.   </p><p>The space tourism market hasn’t been cornered by Bezos alone. Other aerospace and tech companies, including SpaceX, <a href="https://www.theguardian.com/business/2021/jan/12/uk-nuclear-spacecraft-could-halve-time-of-journey-to-mars-rolls-royce">Rolls Royce</a>, and Virgin Galactic, have entered <a href="https://www.pbs.org/wgbh/nova/video/rise-of-the-rockets/">the commercial space race</a>, expanding the <a href="https://www.nytimes.com/2021/07/26/science/jeff-bezos-astronaut-definition.html">definition of an astronaut</a> and allowing those who can afford it the opportunity to venture beyond Earth’s atmosphere.</p>
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<img alt="Mars rover and space helicopter on sandy ground" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/Percy_And_Ingenuity.width-990_CA5Poai.jpg"/>
<figcaption><p>A dynamic duo: In this illustration, the Mars Perseverance rover and first-ever space helicopter, Ingenuity, stand upon the Martian surface. Image Credit: NASA/JPL/CalTech</p>
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<p>Meanwhile, NASA also hit exploration milestones this year, many of which took place on Mars. NASA’s fifth Mars rover, Perseverance, <a href="https://www.pbs.org/wgbh/nova/article/nasa-perseverance-mars-rover-landing-success/">successfully landed</a> on the red planet in <a href="https://www.pbs.org/wgbh/nova/video/first-ever-mars-mission-videos/">February 2021</a>, carrying with it a small space helicopter. Perseverance spent 2021 searching for the remains of microscopic life in Mars’ Jezero Crater, a dry, 28-mile-wide valley that scientists believe was a <a href="https://mars.nasa.gov/mars2020/mission/science/landing-site/">river delta</a> on the planet 3.5 billion years ago. If Perseverance can find signs of past microbial life in Jezero Crater’s sediment, scientists will be able to piece together more clues about <a href="https://www.pbs.org/wgbh/nova/video/looking-for-life-on-mars/">Mars’ past and present</a>.</p><p>In April, the four-pound space helicopter Ingenuity became the first human-made craft to lift off on another planet when it <a href="https://www.pbs.org/wgbh/nova/article/nasa-ingenuity-first-powered-flight-mars/">achieved controlled, powered flight</a> only weeks after arriving on Mars. <a href="https://www.pbs.org/wgbh/nova/article/nasa-ingenuity-mars-helicopter-first-flight/">The flying rotorcraft’s</a> mission is to chronicle Mars’ terrain in a way rovers haven’t been able to. While its engineers initially planned for a total of five flights, Ingenuity has logged <a href="https://mars.nasa.gov/technology/helicopter/#">18 flights</a> and counting–totaling more than 30 minutes aloft.</p>
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<h3><b>Brood X cicadas</b></h3><p>In May and June, 15 states braced themselves for a noisy invasion. Brood X cicadas, X being the Roman numeral for 10, are one of 15 broods that appear in the continental U.S. After gestating for <a href="https://www.nps.gov/articles/000/cicadas-brood-x.htm">17 years underground</a>, the cicadas emerged in huge numbers this year, becoming a source of fascination <a href="https://www.sciencenews.org/article/cicada-science-brood-x-2021">for citizen scientists</a>, nature lovers, and <a href="https://www.youtube.com/watch?v=uesOvmv-mFc&amp;t=4s">insect-eating enthusiasts</a> alike.</p><p>Cicadas are essentially defenseless after crawling above ground. Unlike other bugs that sting and bite, male cicadas use their distinctive song—the loudest noise in the entire insect world—to keep <a href="https://www.nature.com/scitable/blog/accumulating-glitches/cicadian_rhythms_why_does_the/">predators at bay</a>. Their screaming, rattling “song” is created by expanding and contracting a membrane in their abdomen <a href="https://www.tennessean.com/story/news/american-south/2021/05/10/cicadas-brood-x-what-to-know/4936745001/">called a tymbal</a>. And while the sound may annoy predators and humans, the call is irresistible to female cicadas. To indicate they want to mate, females make clicking sounds in response to males’ mating calls. In a matter of weeks, cicadas breed, lay eggs, and die. Another 17 years later, a new batch of Brood X—their offspring—will emerge.</p><p>Before having a chance to mate, some of Brood X’s cicadas fell victim to <a href="https://www.vox.com/22445929/dogs-eating-cicadas-brood-x-fish-bait-birds">birds, squirrels, dogs</a>, and other predators, including people. After all, “cicadas are an extremely versatile and tasty ingredient. You can fry them, roast them, pulverize them, or even eat them raw, as if they were oysters,” Sandra Gutierrez G. <a href="https://www.popsci.com/diy/cicada-cooking-guide/">wrote for Popular Science</a> in May. The <a href="https://podcasts.apple.com/us/podcast/would-you-eat-insects-to-help-the-planet/id1526878803?i=1000540051039">consumption of insects</a>, called entomophagy, could benefit human health and help <a href="https://www.pbs.org/wgbh/nova/video/insects-protein/">curb greenhouse gas emissions</a> tied to the meat industry, NOVA reported in October. If you missed your chance to eat cicadas this year, take note for 2038: Chef Joseph Yoon of Brooklyn Bugs says a <a href="https://www.popsci.com/diy/cicada-cooking-guide/">freshly molted cicada is the tastiest of all</a>.</p>
<h3><b>Climate change and extreme weather</b></h3><p>In August, the Intergovernmental Panel on Climate Change (IPCC) released its sixth climate assessment report, detailing the changes necessary to stop global temperatures from rising to levels that would cause undue environmental harm as well as potential steps to keep greenhouse gas emissions low enough to prevent widespread climate-related disasters. There were temporary declines in carbon emissions in 2020 as a result of pandemic shutdowns, but the switch to remote work for many office-goers was not exactly <a href="https://www.theguardian.com/environment/2021/aug/02/is-remote-working-better-for-the-environment-not-necessarily">friendlier for the environment</a>. The IPCC’s conclusion? Yes—humans are warming the planet. It’s warmed to 1.09℃ since preindustrial times, and many of the changes as a result of this are irreversible. If global warming stays below 1.5℃, particular damages, such as marine heatwaves and sea level rise, may reduce in frequency in the coming years. But if it exceeds 1.5℃ or even 2℃, the planet will see a significant and harmful shift in the <a href="https://ideas.ted.com/new-sixth-ipcc-report-on-climate-change-key-takeaways/">frequency and progression</a> of these and other climate damages. Extreme weather has become more frequent and intense since 1950, the IPCC also reported, a shift perhaps exemplified this year by <a href="https://www.npr.org/sections/goatsandsoda/2021/05/30/1000530563/buried-alive-in-mongolias-worst-sandstorms-in-a-decade">sandstorms</a>, <a href="https://edition.cnn.com/2021/08/30/weather/hurricane-ida-monday/index.html">hurricanes</a>, and <a href="https://yaleclimateconnections.org/2021/12/super-typhoon-rai-plows-through-the-philippines/">typhoons</a>.</p><p>On December 13, in a virtual press briefing at the annual meeting of the American Geophysical Union, researchers warned that <a href="https://www.pbs.org/wgbh/nova/article/warm-water-found-beneath-thwaites-glacier-antarctica/">Antarctica’s Thwaites glacier</a> could collapse within three years. Nicknamed the “doomsday glacier," Thwaites is the size of Florida and could cause sea levels to rise as much as two feet. As of 2020, the gradual melting of Thwaites already accounts for 4% of global sea level rise on an ongoing basis. The amount of ice flowing from it and its glacial neighbors has almost doubled in the last 30 years. According to the latest reports, “Warming ocean water is not just melting Thwaites from below; it's also loosening the glacier's grip on the submerged seamount below, making it even more unstable,” Mindy Weisberger <a href="https://www.space.com/agu-antarctica-thwaites-glacier-future">writes for Space.com</a>. Current mathematical models illustrate that if the glacier were to collapse, much of western Antarctica’s remaining ice would become unstable. </p>
<h3><b>Bidding farewell to Hubble; saying hello to James Webb</b></h3><p>The Hubble Space Telescope launched on April 24, 1990, and for more than 30 years has delivered <a href="https://www.pbs.org/wgbh/nova/article/hubble-space-telescope-best-images/">images of the cosmos</a>, detected the chemical composition of exoplanet atmospheres, and illustrated how stars form (<a href="https://www.pbs.org/wgbh/nova/article/star-explodes-supernova-hubble-tess/">and explode</a>). Though Hubble is still working, the aging telescope—last updated in 2009—was succeeded by the <a href="https://jwst.nasa.gov/content/webbLaunch/index.html">James Webb Space Telescope</a> (JWST), which launched from French Guiana on <a href="https://www.nature.com/articles/d41586-021-03655-4">Christmas Day 2021</a>. During its 30-day, one-million-mile journey to a spot about four times farther away than the Moon, the JWST will gradually unfold into its final form. With a 21-foot-wide mirror and a cost of $10 billion, <a href="https://www.pbs.org/wgbh/nova/article/-james-webb-space-telescope-launch-nasa-big-bang/">the JWST</a> is the largest, most powerful, and most expensive telescope ever to be launched into space. </p>
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<img alt="James Webb Space Telescope full deployment" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/JWST_4.width-990_9vOXAwI.jpg"/>
<figcaption><p>Twenty-nine days after its launch, the world’s most advanced telescope will unfurl in its entirety—assuming it skirts past nearly 350 points of failure. Image Credit: NASA's Goddard Space Flight Center Conceptual Image Lab</p>
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<p>Completed in 2019, right before the pandemic slowed most operations, the telescope sports gold-plated beryllium mirrors optimized for reflecting infrared light, which will help it observe distant galaxies—including those that formed shortly after <a href="https://podcasts.apple.com/us/podcast/the-big-bang-started-from-inflation-now-were-here/id1526878803?i=1000543773247">the Big Bang</a>. (As the universe constantly expands, the light from stars and galaxies shifts over time from our perspective here on Earth. By the time the light from the Big Bang’s earliest creations reaches Earth, it’s stretched from visible blue light to heat radiation that’s invisible to the naked eye and optical telescopes, but whose infrared waves can be detected by a colossal infrared telescope like the JWST.) </p><p>Besides observing some of the earliest galaxies in our universe, the JWST will peer through the dense dust clouds where stars and planets form, helping scientists better understand the evolution of these celestial bodies once the telescope reaches its targeted location in space. The telescope will also help researchers study the atmospheres of exoplanets, using its infrared instruments to peer at water vapor, methane, carbon dioxide, and other chemical compounds. The JWST team hopes that the telescope’s observations could help reveal clues about our universe’s future. One thing is for certain: The possibilities of an astronomical telescope with years of universe-gazing ahead of it seem endless.</p>
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<p data-block-key="s5dhi">Scientific advancements helped humans push through both the pandemic and the atmosphere this year, and a long-awaited visit from some underground insects set the country abuzz.</p>

A person in the first stages of multiple sclerosis may have trouble gripping objects or experience dizziness, fatigue, and vision problems. Symptoms may get progressively worse. Image Credit: © Minerva Studio/Shutterstock

Epstein-Barr infection found to increase risk of multiple sclerosis

<p>Multiple sclerosis (MS) is an incurable autoimmune disease that afflicts 2.8 million people worldwide. People diagnosed with MS experience progressive damage to their central nervous system and can lose about seven years of their life expectancy, according to the National Multiple Sclerosis Society. </p><p>Now, using data from more than 10 million U.S. military recruits monitored over a 20-year period, researchers at the Harvard T.H. Chan School of Public Health determined that the biggest risk factor for contracting the disease may be previous infection with the Epstein-Barr virus (EBV). The team published its findings on January 13 in the journal <a href="https://www.science.org/doi/10.1126/science.abj8222">Science</a><i>.</i></p>
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<p>While there are nearly 1,000 genetic precursors for MS, including sex, “no risk factor stands out like Epstein-Barr infections,” epidemiologist and Principal Investigator of the study Alberto Ascherio <a href="https://www.nytimes.com/2022/01/13/health/multiple-sclerosis-epstein-barr-virus.html">told The New York Times.</a> In fact, nearly every case of MS observed by Ascherio and his team was preceded by infection with EBV, a common strain of herpes spread through saliva and other bodily fluids. Of the 10 million military personnel involved in the study, 955 were diagnosed with MS during their service. Risk of MS increased 32-fold after infection with EBV, researchers found, a correlation not seen with any other viruses that the subjects contracted during their service. Additionally, other clinical biomarkers of MS increased only after EBV antibodies were detected in the patients' blood.</p><p>Researchers say the findings suggest that EBV is the leading contributor to the development of MS. But how EBV leads to MS remains “unknown and elusive,” two Stanford University immunologists who were not involved in the study told <a href="https://www.scientificamerican.com/article/epstein-barr-virus-found-to-trigger-multiple-sclerosis/">Scientific American</a>.</p><p><a href="https://www.cdc.gov/epstein-barr/about-ebv.html">According to the CDC</a>, most people will be infected with EBV at some point in their lives. The virus also causes mononucleosis, commonly called “mono,” which more than 3 million people fall ill with every year in the U.S. Initial EBV infections cause few symptoms, but once EBV gets into the body’s immune cells, “it lurks in them permanently,” Michael Le Page <a href="https://www.newscientist.com/article/2304340-strongest-evidence-yet-that-ms-is-caused-by-epstein-barr-virus/">writes for New Scientist.</a></p><p>But contracting EBV will not necessarily lead someone to develop MS, the study authors caution. “Most people infected with this common virus do not develop multiple sclerosis,” the team reports in its paper. Still, like many other common viruses, EBV’s potential to wreak havoc on the body through reactivation is cause for investigation. There is currently no vaccine for EBV. Its status as a "non life-threatening" illness has led to a “lack of investment” in creating a vaccine, Michael Wilson, a neurologist at the University of California San Francisco <a href="https://www.statnews.com/2022/01/13/strong-new-evidence-suggests-virus-triggers-multiple-sclerosis/">told STAT News</a>. A preventative vaccine against EBV—much like the one launched for human papillomavirus (HPV), a common virus that in rare cases can cause cancer—may reduce the incidence of MS. “Studies like this suggest we should be pushing harder on developing a vaccine against EBV,” Wilson told STAT News.</p>
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<p>MS is diagnosed with an MRI of a person’s brain, usually between the ages of 20 and 50. In MS patients, a brain scan reveals small lesions, which are dead networks of thousands or millions of neurons. People who develop MS tend to have overactive immune systems, Gina Kolata writes for The New York Times. Patients may report “never getting a cold,” because their immune systems so quickly fight off viruses. </p><p>Neurons are insulated by myelin sheaths, which not only protect the cells but also facilitate communication from the brain to the rest of the body. In MS patients, the immune system eats away at these myelin sheaths. Without the ability to send messages from the brain to the body, a person in the first stages of MS may have trouble gripping objects or experience dizziness, fatigue, and vision problems. As a patient’s immune system continues to attack their myelin sheaths, their symptoms may get progressively worse.  “But what triggers the immune system to turn on itself,” Megan Molteni writes for STAT News, “is still a mystery.” </p><p>The connection between EBV and MS is helping demystify some of the questions around the debilitating chronic disease and accelerating vaccine development. Both Moderna, one of the first companies to produce an mRNA COVID-19 vaccine, and the National Institute of Allergy and Infectious Diseases are looking into manufacturing an EBV vaccine. This month, Moderna launched its first phase trial for an mRNA vaccine against EBV. If successful, Lydia Denworth reports for Scientific American, the vaccines could reduce the incidence of mono, some EBV-associated cancers, and potentially MS. </p>
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<p data-block-key="dagjl">The underlying cause of multiple sclerosis is not yet known, but Epstein-Barr virus is a possible culprit, Harvard researchers say.</p>

An artist's concept of a near-Earth asteroid like 2022 EB5. Image Credit: NASA/JPL-Caltech

Astronomers successfully predict an asteroid impact above Iceland

<p>On Friday, Mar. 11 at around 7:30 p.m. GMT, an astronomer spotted an asteroid hurtling toward our planet at an estimated speed of 39,600 mph. By 9:30 p.m., the asteroid, dubbed “2022 EB5,” entered Earth’s atmosphere. It disintegrated over Jan Mayen island near Iceland, its pieces most likely plunging into the Arctic Ocean, the International Meteor Organization <a href="https://www.imo.net/2022-eb5-5th-predicted-earth-impactor-asteroid-on-march-11/">reports</a>. 2022 EB5’s descent marks the fifth time astronomers successfully mapped out an asteroid’s collision course with Earth ahead of impact.</p>
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<p>Krisztián Sárneczky, the astronomer who first spotted 2022 EB5, was at Konkoly Observatory’s Piszkéstető Mountain Station near Budapest, Hungary when he made the observation. Soon after reporting his finding of a mysterious object hurtling toward Earth to the International Astronomical Union's Minor Planet Center, fellow astronomers identified it as a near-Earth asteroid. “The sighting soon got a lot more interesting,” Chelsea Gohd <a href="https://www.space.com/asteroid-discovered-hours-before-earth-atmosphere-impact">writes for Space.com</a>. “​​Just 30 minutes after the discovery, data showed that the space rock was a mere two hours away from colliding with Earth's atmosphere.”</p><p>2022 EB5 belongs to the Apollo asteroids, space rocks considered by NASA to be “potentially hazardous” because of the close approaches they make to Earth. Named for 1862 Apollo, an asteroid discovered by German astronomer Karl Reinmuth 90 years ago, it takes Apollo asteroids less than two years to orbit the Sun. Asteroid 2022 EB5, which astronomers believe was 10 feet wide prior to its descent to Earth (or as some news outlets say, “<a href="https://www.sciencetimes.com/articles/36593/20220314/asteroid-half-size-giraffe-hits-iceland-2-hours-astronomers-spotted.htm">half the size of a giraffe</a>”) quickly caught headlines and the attention of social media users on <a href="https://www.reddit.com/r/worldnews/comments/te89dm/asteroid_half_the_size_of_a_giraffe_strikes_earth/">platforms like Reddit</a>.</p>
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<img alt="Asteroid headed toward Earth illustration" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/Asteroid_Illustration.width-990_EDj4GHj.jpg"/>
<figcaption><p>NASA scientists predicted asteroid 2022 EB5's trajectory before hitting the Earth’s atmosphere on Mar. 11, 2022. The asteroid—estimated to be about 6.5 feet wide—was discovered only two hours before impact. Credit: NASA/JPL-Caltech</p>
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<p>Shortly after Sárneczky’s observation and report, NASA's "Near-Earth Asteroid Scout" (NEA Scout), “a miniaturized spacecraft known as a CubeSat,” <a href="https://www.nasa.gov/content/nea-scout">NASA writes</a>, began calculating 2022 EB5’s trajectory toward our planet. "As soon as Scout determined that 2022 EB5 was going to hit Earth's atmosphere," NASA's <a href="https://www.jpl.nasa.gov/news/nasa-system-predicts-impact-of-small-asteroid">Jet Propulsion Laboratory (JPL) reports</a>, NEA Scout alerted NASA's Center for Near Earth Objects (CNEOS) and its Planetary Defense Coordination Office, which is managing a new asteroid-deflection mission called <a href="https://www.youtube.com/watch?v=nGwnl7K5IWc">DART</a>. After only 40 minutes, NEA Scout and its team of scientists were able to predict 2022 EB5's exact impact time and location.</p>
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<p>Asteroids like 2022 EB5 are not big enough to be a hazard to our planet or society, researchers believe. Though 2022 EB5 likely “started out about 10 feet wide,” Kelly Kizer Whitt writes for <a href="https://earthsky.org/space/asteroid-discovered-hours-before-earth-impact-eb5/">EarthSky,</a> 2022 EB5 sizzled during its descent to about 6.5 feet according to NASA estimates, "much smaller than the objects that the Planetary Defense Coordination Office is tasked by NASA with detecting and warning about," NASA JPL reports. In fact, tiny asteroids "impact the atmosphere quite frequently," <a href="https://www.jpl.nasa.gov/news/nasa-system-predicts-impact-of-small-asteroid">CNEOS Director Paul Chodas</a> told NASA JPL. But unlike 2022 EB5, “very few of these asteroids have actually been detected in space and observed extensively prior to impact," Chodas said.</p><p>In fact, “this is probably a once in a lifetime experience for an ‘asteroid hunter,’” Sárneczky told Space.com.</p><p>2022 EB5's fiery plummet to the Earth may have caused a brilliant, visible shooting star, astronomers believe, but no citizen observations have been reported. While the remnants of some other Earth-striking asteroids have been recovered, "all of 2022 EB5 almost certainly burned up or fell into the Arctic Ocean," Eric Mack writes for <a href="https://www.forbes.com/sites/ericmack/2022/03/13/astronomer-spotted-an-asteroid-just-hours-before-it-impacted-earth/?sh=2f30ff9558fc">Forbes</a>, so it’s unlikely humans will recover pieces of the asteroid. Still, 2022 EB5 now joins an exclusive cosmic club of asteroids—2008 TC3, 2014 AA, 2018 LA, and 2019 MO—each named for their year of impact and whose collision courses with Earth were discovered before they came in contact with our atmosphere.</p>
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<p data-block-key="644tf">Two hours before asteroid 2022 EB5 entered Earth’s atmosphere, scientists knew exactly when and where the space rock would strike.</p>

Hanna Ali

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