August 4, 2023: A view of the Milky Way, early mammals ate bugs and environmental impacts of the war in Ukraine. All and more below. —Andrea Gawrylewski, Chief Newsletter Editor | | | On a clear night in the coming week or two, if you can find a dark spot, look up! You'll see stars down to magnitude 4.0 or 5.0 ( read about the star magnitude scale here) when the moon rises late, or not at all. Also visible will be a broad whitish swath across the sky, stretching from the northern horizon to nearly directly overhead and then down again to the southern horizon. This is the Milky Way. Modern measurements put the disk of our galaxy at 120,000 light-years across.
Why this is so cool: Over the centuries, the makeup, size, shape, as well as our placement in the Milky Way, have slowly come into focus. Scientists from Galileo to William and Caroline Herschel to Edwin Hubble all turned their sites on the river of stars overhead. In just the last decade radio astronomers have plotted a more precise map of the galaxy than ever before, using data points from thousands of hours of observing time.
What the experts say: Mysteries remain about our cosmic home. Two competing ideas explain how its spiral arms formed in the first place. And the Milky Way's precise age is still fuzzy. | | | The Milky Way shines bright over the Southern Utah desert as juniper trees stand in the foreground. Credit: Eric Hanson/Getty Images | | | New research hints that mammals' huge success on Earth might be linked to a surprisingly small dietary choice from early in their evolution: insects. By analyzing the skulls of cynodonts–tiny, weasel-like reptiles that were precursors to mammals more than 220 million years ago–scientists saw bone patterns that resembled modern insectivores.
Why this matters: Paleontologists had long wondered why early mammals had fewer teeth and skull bones than they do today. The new findings show these were well-suited to chomping on insects, and also a good foundation for later adaptations so that mammals could feed on plants and larger animals.
What the experts say: "These findings suggest the patterns we see in the evolution of mammal skulls are more nuanced than we might have thought," says Elsa Panciroli, a paleontologist from the Oxford University of Natural History. | | | • A background "hum" pervades the universe. Scientists are racing to find its source. | 7 min read | | | • Construction has begun on the Vineyard Wind project off the coast of Massachusetts. It could provide enough clean energy to power 400,000 homes per year. | 5 min read | | | • Explorers of space and the deep sea face similar dangers, but some differences make one realm safer than the other. | 8 min read | | | • Naomi Livesay worked on computations that formed the mathematical basis for implosion simulations of the atomic bomb. Despite her crucial role on the project, she is rarely mentioned as more than a footnote. | 16 min listen | | | • The war in Ukraine is having devastating environmental and human health consequences, namely the destruction of the Nova Kakhovka Dam several weeks ago, which washed away vegetation, eroded riverbanks and sent 150 tons of heavy fuel oil into drinking water sources. "We must address the war's environmental and health catastrophes when reconstruction efforts become possible," write Jennifer R. Littlejohn, Raffi Balian and Luke Simmons. Littlejohn and Balian are career foreign service officers. Simmons is a public affairs specialist at the Bureau of Oceans and International Environmental and Scientific Affairs. | 5 min read | | | ICYMI (Our most-read stories of the week) | | | • Why Do Dogs Tilt Their Head to the Side? | 3 min read | | | • $1 Million Will Go to the Mathematician Who Busts the 'ABC Conjecture' Theory | 5 min read | | | • Bizarre-Looking Colossus Whale May Have Been Heaviest Animal Ever (Sorry, Blue Whales) | 4 min read | | | It might be surprisingly difficult to find a place dark enough to see our galaxy with the naked eye; more than 80 percent of humanity is affected by light pollution. Find a dark sky location by searching this site. Enjoy the Milky Way if you can spot it! | This newsletter is for you, so please reach out and let me know how I can improve it! newsletters@sciam.com. Have a wonderful weekend! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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