Science Friday

The Science Of Your Summer Vegetable Garden Planting and tending to a vegetable garden is both an art and a science. If all goes well, you’ll be enjoying delicious homemade salads all summer long. But if your tomatoes get too little water, or if the soil is too acidic, or if pests get to the lettuce before you do, then all that hard work may have been for nothing. Whether you’re a seasoned grower or first-time gardener, it’s never a bad idea to hear what the experts have to say. Years ago there was a radio program in New York called “The Garden Hotline,” hosted by horticultural expert the late Ralph Snodsmith. Every Sunday morning on WOR, Snodsmith fielded listeners’ questions, such as: “Can coffee and tea grounds help acidify my soil? Not to any marked degree. Can seedlings thinned from a row of lettuce be used as transplants? If you’re careful with their tiny roots, yes. Is it better to plant my tomato transplants into the garden on a sunny or cloudy day? Cloudy, since reduced light exposure reduces transpiration.”  This week, Science Friday pays homage to Snodsmith’s original radio program and others like it, answering questions about the science of your summer vegetable garden. Ira is joined by Elizabeth Buck, fresh market vegetable production specialist with Cornell Cooperative Extension, and Gary Pilarchik, hobbyist gardener and host of the YouTube channel The Rusted Garden, to answer SciFri listener questions in front of a live Zoom audience. Recalling The Life Of Benjamin Franklin, Scientist Benjamin Franklin was a printer, politician, diplomat, and journalist. But despite only two years of schooling, he was also an ingenious scientist. In this conversation from 2010, Nobel Prize-winning chemist Dudley Herschbach and Ben Franklin biographer Philip Dray discuss the achievements of the statesman-scientist.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

The Alarming Impacts Of Extreme Heat This week, the Pacific Northwest was hit by a record breaking heat wave, with temperatures rising as high as 116 degrees Fahrenheit in Portland, Oregon. Experts say of all the extreme weather events brought on by climate change and heat waves stand to do the most damage to the environment, infrastructure, and human health. Umair Irfan, staff writer for Vox, joins Ira to share more about the alarming impacts of such extreme heat. Plus, as record-breaking heat becomes more common, air travel may get more difficult. And physicist Rhett Allain explains why airplanes have trouble getting off the ground as the temperature rises.   How Alarmed Should You Be About The Delta Variant? It’s been six months since the first variant of COVID-19 raised alarm bells around the world. Now, a particular variant seems to be spreading rapidly: the Delta variant, first identified in India, and now the dominant strain in many countries, including the United Kingdom. In the United States, the variant makes up more than 20% of cases. South Africa, Australia, Germany, and other countries are re-imposing limits on travel and daily life. And Israel, where more than 60% of people are vaccinated, has reinstated mask requirements. In fact, the World Health Organization is recommending that all fully vaccinated people continue to wear masks as this variant spreads. What does that mean for you? Virologist Angela Rasmussen helps take the temperature of the Delta variant and other COVID-19 news—including promising results on the Novavax vaccine, clues about long-lasting immunity from Pfizer’s mRNA shot, and more.     How Edgar Allan Poe Exposed Scientific Hoaxes—And Perpetrated Them “Leave my loneliness unbroken!—quit the bust above my door!Take thy beak from out my heart, and take thy form from off my door! Quoth the Raven “Nevermore.” When you think of Edgar Allen Poe, poems like “The Raven” and “The Telltale Heart” may pop to mind. But throughout the poet’s life, he was absolutely fascinated by science. His love of subjects like astronomy and physics—along with the tragedy that followed him throughout his life—informed his poems and essays. Through this work, Poe may have also had an impact on science itself. Poe’s scientific life is investigated in the new book, The Reason for the Darkness of the Night: Edgar Allan Poe and the Forging of American Science. In many ways, it explains, Poe’s scientific fascination was a product of its time. He grew up in the early 1800s, which was a time when a widespread thirst for knowledge was beginning to flourish. Poe loved to expose scientific hoaxes, while simultaneously perpetrating them himself. And his self-proclaimed magnum opus, a largely unsuccessful venture, was a nonfiction essay about the nature of the universe, called “Eureka.” Author John Tresch joins Ira to discuss Poe’s life, legacy, and works. Tresch is professor of history of science at the Warburg Institute in the University of London, based in London, England. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

California’s Climate Program Is Actually Adding Carbon To The Atmosphere California has a reputation as the state that’s doing the most about climate change. And the lynchpin of those efforts is California’s Cap-and-Trade program, where the state’s biggest polluters—like ExxonMobil, BP, and others—are required to offset their carbon dioxide emissions by investing in carbon reduction strategies. But according to a recent investigation by ProPublica and others, this climate solution is actually adding millions of tons of carbon to the atmosphere. They discovered a loophole in the state’s forest offset program, which seeks to reduce carbon emissions by preserving trees. Uncovered by additional reporting, they found that the Massachusetts Audubon Society, a forest conservation organization, enrolled 9,700 acres it owned into California’s program and received the credits, even though it was unlikely that Mass Audubon ever intended to cut down its preserved forests. The intended use of these offsets was to change the behavior of landowners who were likely to cut down trees, releasing carbon dioxide in the atmosphere. The result, in this instance, seemed to go against the spirit of the Cap-And-Trade program, that the state’s biggest polluters’ emissions weren’t truly being offset. Guest host Sophie Bushwick is joined by Lisa Song, a ProPublica reporter who broke this story with MIT Technology Review, with help from Carbon Plan, a nonprofit that analyzes the scientific integrity of carbon removal efforts. Read Lisa’s investigative story here.     A Monterey Bay Aquarium Scientist Gives Fun Facts About Cephalopods It’s the most wonderful time of the year! No, not the holidays—it’s Cephalopod Week, and SciFri uses any excuse to celebrate the mysterious squid, the charismatic octopus and the cute cuttlefish. If anyone matches SciFri’s enthusiasm for marine invertebrates, it’s the folks at the Monterey Bay Aquarium. Guest host Sophie Bushwick talks to Christina Biggs, senior aquarist at the Monterey Bay Aquarium in Monterey, California. Biggs spills behind-the-scenes details about everything from raising cephalopods from eggs to how their dietary preferences can resemble those of picky toddlers. “She’ll come right over to grab food,” Biggs says of one of the aquarium’s Giant Pacific Octopuses. “And on Sardine Sundays, she just tosses it right over her head and just waits for something better.” Can’t get enough of Cephalopod Week? Listen to the latest episode of SciFri’s Science Diction podcast, or check out some fun cephalopod-themed videos on TikTok.     The Long Tail Of Long COVID As the highly transmissible delta variant of COVID-19 continues to spread, it now makes up more than 20% of cases in the United States—including in Missouri, where cases are the highest since mid-February. Meanwhile, a new report finds the number of people experiencing long-term COVID symptoms is as high as 23% of those who have ever had the disease, including people who never had symptoms in their initial infection. The report from FAIR Health, which surveyed the insurance records of more than two million people, is the largest yet to investigate long COVID. Guest host Sophie Bushwick talks to the MIT Technology Review’s Amy Nordrum about the long reach of COVID-19. Plus a bet about improbable physics, the arrival of baby bobtail squid at the International Space Station, and what happens when a spider eats a snake. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Is The Truth About UFOs Out There? Over the past several years, U.S. Navy pilots have reported several instances of ”unexplained aerial phenomena” while in flight. They’ve recorded videos that show shapes that appear to move in unusual ways, zooming and turning in ways  beyond the capabilities of our own aircraft. After several members of Congress requested an explanation for the videos, the government put together a report on the phenomena.   The report, however, doesn’t definitively answer the question of what the observations show. While it does say that the observations aren’t of secret U.S. technology, it has no conclusions on whether the reports show foreign technology, camera artifacts, or something else—like alien technology. Seth Shostak, senior astronomer at the SETI Institute, spends his time searching for signs of intelligent life elsewhere in the universe. He says that while he does believe intelligent alien life exists—and may even be discovered within the next 20 years or so—he does not think the sightings included in the government report indicate alien visitors. He shares his reasons for skepticism with host Sophie Bushwick, as well as talks about people’s desire to believe in extraterrestrials.  Rats Learn To Hide And Seek  One of the most wonderful things about the internet is how you could spend years watching videos of animals at play. There’s the classic cat-playing-with-a-box genre. You can also watch a dog playing jenga. And you can type in pretty much any combination of animals, along with the word “playing,” and find adorable videos—like a baby deer, rough-housing with a lemur. Incredible stuff.  Neuroscientist Juan Ignacio Sanguinetti of the Humboldt University of Berlin gets inspiration for his work by watching home videos like that. And in his latest work, in the journal Science, he describes playing hide-and-seek—with rats. Making Music To Sharpen Aging Brains While research continues on drugs that can slow or reverse the- damage of Alzheimer’s disease, there is already evidence for a lower-tech intervention: music. Research on the benefits of listening to music has found some evidence that it can activate regions of the brain not damaged by disease progression, soothe emotional disturbances, and promote some cognitive improvement in later stages of Alzheimer’s. A new analysis in the Journal of the American Geriatric Society earlier this year looked at a different question. Can making music, whether by playing a musical instrument or singing, have an effect on the brains of people in the early stages of cognitive decline? The team focused specifically on people experiencing ‘mild cognitive decline,’ which can be the first step in a progression toward Alzheimer’s disease or more serious dementia. The researchers found evidence from 21 studies, involving more than 1,400 participants around the world, that yes, playing musical instruments, singing, or otherwise participating in making music can have a small but consistent benefit in recall, and other measures of brain health. Lead author Jennie Dorris, a professional percussionist turned PhD student studying rehabilitation sciences, talks to guest host Sophie Bushwick about the evidence for cognitive improvement, and what questions still remain about the effects of active music participation on the brain. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

COVID-19 Vaccines May Not Protect Immunocompromised People This week, California and New York, two of the states hardest hit by the COVID-19 pandemic, announced that they were relaxing almost all coronavirus-related business restrictions. Across the country, vaccination numbers are slowly ticking up—although a troubling COVID-19 variant known as Delta is picking up as well. As things reopen, experts warn that people with compromised immune systems may not be well protected, even if they do get the vaccine.  There are many reasons someone might have a weakened immune system, including an illness, cancer treatment, or the use of immune-suppressing drugs needed for an organ transplant. But regardless of the reason, immunocompromised people may not be able to mount a strong antibody response to the vaccines.  Dr. John Mellors, chief of the division of infectious diseases at the University of Pittsburgh Medical Center, and Dr. Lindsay Ryan, an internist at UCSF in San Francisco who is herself immunocompromised, talk with Ira about what we know about the performance of COVID-19 vaccines in immunocompromised people, and what people with weakened immune systems can do to help protect themselves against the illness.   The Best Sci-Fi Books To Read This Summer Whether you’ve had a hard time reading during the pandemic, or you zoomed through your book pile and are craving more, Science Friday’s annual list of the best summer science books is here for you.  As the world begins to open up, many of us are not quite comfortable traveling like we once did. But what a better way to escape without going too far than by immersing ourselves in some science fiction? Hit the beach—and another dimension, travel to space from the safety of your backyard, or take a hike back in time to an alternate era.  And this summer we tapped two sci-fi aficionados to help build our list. Annale Newitz, science journalist and author of Four Lost Cities, and Gretchen Treu, co-owner of A Room of One’s Own Bookstore, in Madison Wisconsin, share their superb summer selections with Ira in front of a live Zoom audience.  Get the list of the books recommended by our guests!  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

How To Talk About Medical Marijuana With Your Doctor Over the last decade, cannabis has had a moment. Thirty-six states and Washington D.C. have legalized it for medical use. (Fifteen states, plus D.C., have also legalized weed recreationally.) Altogether, about 5.5 million people in the U.S. now have medical marijuana cards. One of the primary arguments for expanding marijuana laws is the drug’s potential usefulness for medical treatments. While each state has its own rules for which conditions are eligible, issues like chronic pain are nearly universally accepted as a reason for using medical marijuana. But there’s still a large divide between the traditional medical establishment and the cannabis industry. Cannabis is still illegal federally, and a recent study showed that many clinicians feel they don’t know enough about medical marijuana to make a recommendation to patients. This in turn impacts how patients feel about talking to their doctor about using cannabis to treat medical conditions. Joining Ira to talk about the ins and outs of connecting cannabis to the larger medical establishment are Dr. Ziva Cooper, research director for UCLA’s Cannabis Research Initiative in San Francisco, California, and Dr. Donald Abrams, integrative oncologist and professor emeritus at University of California San Francisco’s Osher Center for Integrative Medicine.     What Can Crayfish Tell Us About Drugs In Our Waterways? Wastewater is a grab bag of chemicals. There’s industrial run-off, bits of animal and viral DNA, and then there are compounds that trickle out from our households. The medicines we’re flushing down the toilet or releasing through urine are making their way into countless bodies of water. Antidepressants are one of the drugs that frequently end up in the environment. A team of scientists wanted to study the effects of these antidepressants on streams wending their way through ecosystems. So they looked to none other than the crayfish. They found that crayfish exposed to these drugs were a bit bolder. Their results were published this week in the journal Ecosphere. Freshwater ecologist Lindsey Reisinger and freshwater biogeochemist A.J. Reisinger, who are both authors on that study, talk about how these drugs affect crayfish and potential downstream effects on waterways and the ecosystem.     We Aren’t Squidding Around—It’s Cephalopod Week 2021! The wait is over—Cephalopod Week 2021 is finally here. It’s Science Friday’s annual ceph-lo-bration of all things mostly-tentacled, and this year’s lineup of events is going to be ceph-tacular. Visit behind-the-scenes at the Monterey Bay Aquarium, play deep sea trivia, watch mini documentaries, chat with real scientists working with cephalopods every day, and a whole lot more. Diana Montano, SciFri’s outreach manager and emcee of the deep sea, joins Ira and Science Diction host Johanna Mayer to kick things off, with some trivia about the origins of squiddy words.     Kids Are Benefiting From Adult Vaccinations, Too Something interesting is happening in some communities where most adults are vaccinated against COVID-19: infection rates in kids are going way down, too. Right now, Americans 12 and older are eligible for the vaccine, leaving the country’s youngest still exposed. So this is a promising sign, considering about two-thirds of U.S. adults have received at least one shot of a COVID-19 vaccine. But some experts are saying we still need to be cautious about throwing kids together again before they’re vaccinated. Joining Ira to chat about this story is Maggie Koerth, senior science writer at FiveThirtyEight in Minneapolis, Minnesota. They also talk about other top science stories of the week, including news that cicada broods might emerge more often with climate change.         Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Biden’s New Assistant Secretary Of Health On Protecting Trans Youth The American healthcare system is facing some incredible challenges: Black and Latino communities were hit harder by COVID-19, and have lower vaccination rates than white, Asian, and Native American communities. The opioid crisis is still raging, climate change is disproportionately impacting the health of communities of color, and a wave of anti-trans healthcare bills are being pushed by Republican lawmakers through multiple states. Dr. Rachel Levine, President Biden’s appointee for assistant secretary of health for the department of Health and Human Services, is aiming to take on all of that, and more. She previously served as Pennsylvania’s secretary of health and physician general, combating both the opioid and COVID-19 crises there. Now, she wants to scale those efforts to a federal level, in addition to helping meet President Biden’s goal of getting 70% of adults with at least one vaccine dose by July 4. She also made history as the highest-ranking, openly transgender person to have served in the federal government. Levine talks to Ira about the steps needed to achieve health equity, advocating for the healthcare rights of trans youth and adults, and her ambitions for her time in office.   Why Oxen Were The Original Robots In media and pop culture narratives about robotic futures, two main themes dominate: there are depictions of violent robot uprisings, like the Terminator. And then there are those that circle around the less deadly, more commonplace, fear that machines will simply replace humans in every role we excel at. There is already precedent for robots moving into heavy lifting jobs like manufacturing, dangerous ones like exploring outer space, and the most boring of administrative tasks, like computing. But roboticist Kate Darling would like to suggest a new narrative for imagining a better future—instead of fighting or competing, why can’t we be partners? The precedent for that, too, is already here—in our relationships with animals. As Darling writes in The New Breed: What Our History With Animals Reveals About Our Future With Robots, robotic intelligence is so different from ours, and their skills so specialized, that we should envision them as complements to our own abilities. In the same way, she says, a horse helps us travel faster, pigeons once delivered mail, and dogs have become our emotional companions. Darling speaks with Ira about the historical lessons of our relationships with animals, and how they could inform our legal, ethical, and even emotional choices about robots and AI.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

FDA’s Approval Of Debated Alzheimer’s Treatment Raises Controversy This week, the FDA gave the green light to a drug for the treatment of Alzheimer’s disease. The drug, a monoclonal antibody called aducanumab, is the first Alzheimer’s treatment to receive approval in almost 20 years. It targets the amyloid protein that forms the tangled plaques found in the brains of people with Alzheimer’s. But while researchers agree that aducanumab leads to less amyloid plaque, no one really knows what that means in terms of real benefits for people with the disease. Researchers still don’t understand the role of amyloid in the progression of Alzheimer’s disease—and in two studies conducted by the company Biogen, only one showed taking aducanumab provided a slight cognitive benefit to people with early Alzheimer’s. The other study showed no effect compared to a placebo. However, the FDA elected to ignore the recommendations of an outside advisory panel, and approved the medication under an accelerated approval process. The drugmaker will be required to conduct additional testing on the treatment while it is on the market, and the FDA has the option to rescind approval if a Phase 4 trial fails to show efficacy. Biogen will sell the treatment under the trade name Aduhelm, at a list price of around $56,000 per year—not including the extensive office visits, tests, brain scans, and monitoring that will go along with the course of treatment. Pam Belluck, a writer covering science and medicine for the New York Times, joins host John Dankosky to explain the decision, and how the drug might fit into the larger picture of Alzheimer’s research. When Scientists Get It Wrong A couple of years ago, Julia Strand was trying and failing to replicate a study she’d published. At the time, she was an assistant professor without tenure, and the original study had presented her most exciting finding to date. But when she and her co-authors tried to replicate it, they got the opposite results. Then one night, Julia discovered why. In her original code, she’d made a tiny but critical error, and now, with her reputation and job on the line, she was going to have to tell the world about it. Science is often said to be “self-correcting”—through peer review, replication, and community dialogue, scientists collectively find mistakes in their work, and continually revise their understanding of the world. But what does self-correction look like in practice? And how likely are scientists to admit they’re wrong? Julia eventually submitted her story to the Loss of Confidence Project, which invited psychologists to publicly admit mistakes in their published research. Our guest, Julia Roher, a lecturer in psychology, organized the project, along with two others. In an anonymous survey of 316 researchers, almost half said they had lost confidence in one of their findings, but ultimately, only 13 researchers submitted public testimonials to the project. Brian Resnick, who co-created Vox’s Unexplainable podcast and has written about intellectual humility, explains why we often think we’re right when we’re wrong, how others perceive us when we fess up to mistakes, and what all this means for our trust in science.     Charismatic Creature Corner: Chonky Fish Edition In South Africa in 1938, a young museum curator named Marjorie Courtenay-Latimer was performing one of her regular duties when she saw something incredible. Courtenay-Latimer was tasked with inspecting fish brought in by local fishermen that were considered out of place in the region. That’s how she found what she later called the most beautiful fish she had ever seen: a coelacanth, thought to be long extinct. Courtenay-Latimer’s discovery did not immediately register as a coelacanth, because the creature was thought to have gone extinct at the end of the Cretaceous period, 66 millions years ago. The fish was seen as a modern Lazarus—a mysterious creature brought back from the dead, stumping scientists. At six feet long and 200 pounds, some consider the coelacanth to be a big, beautiful fish. According to Dr. Prosanta Chakrabarty, professor and curator of fishes at Louisiana State University, the coelacanth is the meathead of the sea. “They are chunky,” Chakrabarty said. “You can hold their fin and it feels like you’re shaking somebody’s hand.” Because they’re so old, coelacanths are closer to the human genealogical lineage than they are to any modern fish. But because this is the Charismatic Creature Corner, only one thing really matters: Is it charismatic enough to enter the Charismatic Creature Corner Hall of Fame? Joining guest-host John Dankosky to argue for the coelacanth entering the Charismatic Creature Corner Hall of Fame is SciFri producer Kathleen Davis and Dr. Chakrabarty. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Research Reveals 178 Genes Are Associated With Depression If you have a family member that suffers from depression, chances are you may have more than one. Doctors often say “depression runs in families,” but scientists really had no good idea how—until a major analysis of the genomes of 200,000 military veterans uncovered the 178 genes that influence your risk of major depression.  Science Friday producer Katie Feather talked to Dr. Daniel Levey, assistant professor of psychiatry at Yale University School of Medicine. He explains why there are so many associated genes, and more about the massive database that helped scientists find them. Can Genetic Engineering Help Humans Live In Space? The next ambitious goal for space flight is to send a human to Mars. After decades of sending space probes and rovers, there are now actual plans for human voyages. Elon Musk says the deadline for Space X’s Mars Mission may be as early as 2024.    This raises big questions, both about how to survive the trip, and then inhabit a world hostile to humans. In his new book, The Next 500 Years: Engineering Life to Reach New Worlds, geneticist Christopher Mason says the biggest technical challenges could be met by genetically engineering humans to survive long-term space living.  He is joined by astronaut Scott Kelly, who spent one year in space, to talk about how we might genetically engineer ourselves, and the effects that space flight has on the body.  How Might Technology Shift Our Morality? What is right, and what is wrong? Today’s debates range from the ethics of eating meat, to abortion rights. Conversely, some questions are much less contentious than they once were: we no longer debate whether abducting and enslaving human beings is wrong—it is. And we no longer question technologies like in vitro fertilization.  Author Juan Enriquez says we can thank technological changes for modern shifts in ethical rights and wrongs, from energy technologies that reduce the value of manual labor to social media that boosts the visibility of LGBTQ people. Enriquez writes that technology changes over history have—and will continue to—change the nature of what we consider right and wrong. As he writes in Right/Wrong: How Technology Transforms Ethics, published in 2020, scientific advances in genetic engineering and neuroscience are bound to shift our ethical conversations even further. Think about CRISPR-edited genomes, or the potential privacy violations posed by being able to interpret brain activity. Climate change, and how to combat it, also raises important ethical questions. Enriquez talks to Ira about his work, and what he predicts our future ethical quandaries might look like.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Anthony Fauci Reflects On 40 Years Of HIV/AIDS Research Every week, the Centers for Disease Control and Prevention (CDC) releases its regular report of the latest developments on emerging diseases—a living record documenting decades of medical history, known as the Morbidity and Mortality Weekly Report (MMWR). In May 1981, former MMWR editor Michael B. Gregg got a call about an unusual deadly pneumonia, seen in young gay men in Los Angeles. The tip was from epidemiologist Wayne Shandera, Epidemic Intelligence Service Officer for the Los Angeles County Department of Health. He described the cases of five men, ages 29 to 36, who had developed Pneumocystis carinii, a kind of pneumonia typically seen in cancer and immunosuppressed patients. These men were previously healthy, yet they struggled to fight off the illness with treatment. Two of the patients died. All five were gay. Gregg didn’t know what to make of the cases, but he and CDC experts were compelled to publish the observations in the June 5, 1981 issue of MMWR. Soon after, clinicians around the country began to flag similar cases. The number of infected people rose, as did awareness of the strange collection of symptoms. That summer, the media ran stories about the mysterious disease; the New York Times ran the headline, “Rare Cancer Seen in 41 Homosexuals.” At that time, Ira was a science correspondent for NPR, and was in the thick of covering the nuances of the illness. Today marks 40 years since the first official report on the HIV/AIDS epidemic in the United States, and the beginning of a long-puzzling medical mystery. “I was totally baffled, and did not know what was going on. I thought it was a fluke,” recalls Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, during an interview this week with Science Friday. Read more at sciencefriday.com.     Where Did Watermelon Come From? You may think of watermelon as a red, sweet taste of summer. The watermelon itself is ancient—paintings have been found in Egyptian tombs depicting a large green-striped object resembling a watermelon next to grapes and other sweet, refreshing foods. But if you look at many of the melon’s biological cousins, its red, sweet pulp is nowhere to be found—most close relatives of the watermelon have white, often bitter flesh. So how did the modern watermelon become a favorite summer snack? Back in the 1960s, Russian researchers suggested that one sweeter melon species found in south Sudan might have been a close relative of the modern watermelon. Now, a detailed genetic analysis of a handful of wild melon species, and 400 modern varieties of watermelon from around the world, has concluded that the Kordofan melon from Sudan is, in fact, the closest living relative of the watermelon. Susanne Renner, an emeritus professor at the University of Munich and an honorary professor of biology at Washington University in St Louis, explains the work on the origins of the modern melon—and how knowing the history of the watermelon could lead to new varieties. NASA Plans Two New Trips To Venus This week, President Biden announced the U.S. will donate 75% of its unused COVID-19 vaccine doses to foreign countries via the COVAX global vaccine program. The U.S. has promised to promptly send it’s surplus to South and Central America, Asia, and Africa, where countries are experiencing major shortages. Plus on Wednesday, NASA announced plans to launch not one, but two new missions to explore Venus by the end of 2030. It’s the first time the agency has devoted any mission to Venus in 30 years. MIT Technology Review editor Amy Nordrum joins Ira to discuss the biggest science stories of the week.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.