Tuesday, August 20, 2024

Today in Science: Where the asteroid that killed the dinosaurs came from

Today In Science

August 19, 2024: Bird flu has spread to pet cats, new evidence for what killed the dinosaurs, and mpox in Africa is an international public health emergency.
Andrea Gawrylewski, Chief Newsletter Editor
TOP STORIES

Bird Flu is Spreading

At least 36 pet cats in the U.S. have had confirmed infections of bird flu (H5N1) since March. Two cases recently reported in Colorado were identified as indoor cats, which scientists say is a sign that the virus is widespread in animals and may soon impact more humans. Right now, poultry and dairy workers and other people who may come into close contact with infected animals are the only humans considered at risk of avian influenza.

How this happened: Bird flu is rampant in poultry farms across the country–some 100 million birds have died in the U.S. since 2022, either from the disease or from attempts to control the infections' spread through culling. Nearly 200 herds of dairy cows in 13 states have been infected. Potentially millions of wild birds have died. Some cats contracted the disease on dairy farms, likely by drinking raw milk, and other outdoor cats may have picked up the virus by feeding on birds. The fact that indoor cats contracted H5N1 suggests the disease is more widespread than experts are aware of–the cats might have contracted the virus from a mouse in the house or even a human.

What the experts say:  To protect pets from the virus, don't feed them raw milk or other raw food. Outdoor cats are particularly vulnerable since they are more likely to come into contact with infected animals. Watch for changes in behavior that indicate a pet might be sick, especially a loss of appetite or trouble breathing, and alert your veterinarian. 

It Was Definitely an Asteroid

Scientists have completed an exhaustive analysis of the dust deposited around the globe by an impactor that hurtled into what's now the Gulf of Mexico some 66 million years ago and led to the downfall of the dinosaurs. The researchers measured levels of ruthenium isotopes at three different sites around the globe, as well as from meteorites, other craters from different impacts and multibillion-year-old rocks. They determined that the ruthenium is certainly extraterrestrial in origin and most likely came from a carbonaceous asteroid, which was rich in carbon and organic compounds and must have formed in the outer solar system.

Why this matters: Since the layer of dust from the dino-dooming impact was first discovered in the 1980s, scientists have debated the details of where it came from. Some proposed that the ruthenium and other rare elements could have come from volcanic eruptions during the time period. 

What the experts say: "We measured, we checked, and it all lines up...." with an impact of an asteroid, says Mario Fischer-Gödde, a geochemist at the University of Cologne in Germany who led the new study. "Our result isn't just showing it was a carbonaceous asteroid—it's also the nail in the coffin for the idea that these platinum-group elements came from volcanism or any other terrestrial origin."
LISTEN NOW
GIF of a scene from a new television series OceanXplorers
Science of the Deep
Scientific American podcast host Rachel Feltman sat down with writer and director James Cameron to discuss his new six-part series OceanXplorers, which is out now on Disney+ and Hulu. As a kid, Cameron loved science fiction and fantasy, and realized that an alien world existed right here on Earth, at the bottom of the ocean. With the new series he wanted to capture the process of science, and the experience of the scientists doing the work. "People are driven by curiosity, by the excitement of the investigation, by the excitement of discovery," he says. "And I wanted to bottle that." 

Listen to the full interview here. 
TODAY'S NEWS
• Last week the WHO declared an mpox outbreak in the Democratic Republic of the Congo and other African nations a health emergency of international concern. | 5 min read
• Food banks prevented an estimated 1.8 million metric tons of carbon dioxide emissions last year, according to a new report. | 4 min read
• A satellite launched on Friday from California will track methane super-emitters. | 2 min read
• Fruit seems riper when it's wrapped in netting that matches its optimal color, such as a really orangey orange. This is called the "confetti illusion." | 2 min read
Clementines in a dark orange netting
Fruits such as these clementines look riper and more appetizing when they are offered in a colored net. Karimala/Getty Images
More News
EXPERT PERSPECTIVES
• Most people have a few band-aids and acetaminophen stashed in their medicine cabinets. But there are certain medical items that everyone should keep on hand, regardless of age, writes Howard Zucker, a physician, lawyer and public health expert. Zucker lists five essential medical items that most people neglect to stock. "Despite social media, smartwatches, smartphones and clever apps, first aid kits should hold some relatively inexpensive, but valuable, devices," he says. | 4 min read
More Opinion
PUZZLE OF THE DAY
Image Of The Day
• What comes next in this pattern? Click here to check your answer and read more about this puzzle. Plus, here are today's Spellements and the latest science jigsaw. Have fun!
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I love the philosophy behind James Cameron's vision for OceanXplorers. Scientists are as human as anybody, and they bring their emotions, hopes, and disappointments with them to the laboratory or out in the field on expeditions. If you watch the series I'd love to know what you think!
Email me anytime: newsletters@sciam.com. Thanks for reading and see you tomorrow.
—Andrea Gawrylewski, Chief Newsletter Editor
Scientific American
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Today in Science: Inside the sun's corona

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