March 14, 2025: Did you see the lunar eclipse? Plus, a man lived for 100 days with a heart made of titanium, and dogs are good at sniffing out invasive species. —Andrea Gawrylewski, Chief Newsletter Editor | | | The BiVACOR is a total heart replacement made of titanium. Jason Fochtman/Houston Chronicle via Getty Images | | | • Happy Pi Day! Funny story, Indiana's House of Representatives once voted unanimously to change the value of Pi (to an incorrect number). | 5 min read | | | As familiar as the moon is to us, astronomers still don't quite know how old it is. Our closest celestial neighbor was likely formed when a Mars-sized planetoid slammed into Earth. Lunar rock samples put the collision at 4.35 billion years ago, but planet formation models and zircon fragments from the moon's surface suggest it happened at least 4.51 billion years ago. Why the big gap?
New research: In a new study, scientists used computer modeling and analysis of the 4.35 billion-year-old lunar samples. They believe the samples may actually have come from an event after the moon's formation when it temporarily heated up, causing its surface to melt and then crystallize. How did this happen? As the moon orbited Earth it was squeezed and stretched by Earth's gravity, resulting in "tidal heating events" that melted the surface.
What the experts say: "No previous study has synthesized all the available evidence comprehensively," says Yoshinori Miyazaki, a geophysicist at the California Institute of Technology. "This paper provides a better view in resolving the discrepancies between different age estimates."
More on the moon: The lunar lander Blue Ghost, which made moonfall on March 2, witnessed the total lunar eclipse last night from the surface of the moon, which was technically a solar eclipse from its vantage point on the Mare Crisium landing site. It captured the below image around 3:30am CDT showing the sun emerging from totality behind Earth. | | |
Did you get to see the lunar eclipse last night? William Thompson (related to our own senior editor Andrea Thompson), sent in the below photo he snapped of the blood-red moon over Georgia near the time of totality. Somewhere on that orb at that same moment, Blue Ghost was staring back.
| | | • Thousands of protesters around the world gathered in cities on March 7 to push back against the mass firings, extreme budget cuts and shuttered safety panels at scientific agencies resulting from Trump administration orders. "That kind of activism, mobilizing people to act, is the real business at a protest," writes Dan Vergano, senior opinion editor at Scientific American, summarizing the work of American University sociologist Dana Fisher. "Only if the people protesting organize and draw in more people to effectively resist Trump's moves will all the signs and singing matter," he writes. | 5 min read | | | MOST POPULAR STORIES OF THE WEEK | | | • Microplastics Are Messing with Photosynthesis in Plants | 3 min read | • Earth's Oldest Impact Crater Discovered in Australia | 4 min read | • The 9 Unsolved Mysteries Mathematicians Can't Stop Thinking About | 12 min read | | | Send me your lunar eclipse photos if you snapped any! It was overcast last night in New York City, so not a clear view of the sky. Eclipses are predictable but rare, and you're not guaranteed to spot one, even if you know it's coming. So be glad when you do! | Thanks for reading Today in Science this week. Enjoy your weekend and send any feedback to: newsletters@sciam.com. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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