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A galaxy seems to host two giant black holes, poised to collide in a century

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By Daniel Clery , Science.  Excerpt: Unusual radio signals could be long-sought smoking gun of galactic mergers. Astronomers routinely see galaxies crashing into each other and combining. But the final phase of these cosmic mergers has long proved elusive: two supermassive black holes, each once occupying the center of its own galaxy, closely circling each other within a single, combined galaxy. Now, researchers say they have found compelling evidence of such a pairing. A distant galaxy seems to be firing off two beams of radiation from its center at different angles—a sign that a pair of supermassive black holes lurks at its heart. The two behemoths—each with a mass as large as 1 billion Suns—seem to orbit each other every 121 days. ...In as little as 100 years...the black holes should collide, shaking spacetime itself in a titanic burst of gravitational waves. That final burst “would be a really fantastic gravitational wave signal,” says team leader Silke Britzen of the Max Planc...
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Titanic Shake-Up Could Explain Saturn’s Young Rings and Strange Moons

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By Matthew R. Francis , Eos/AGU.  Excerpt: A new model shows how the migration of Titan could have destroyed another moon, creating Saturn’s rings and the moon Hyperion. And, the model suggests, this all happened in the past billion years....  Full article at https://eos.org/articles/titanic-shake-up-could-explain-saturns-young-rings-and-strange-moons . 
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Gravitational lensing could break the Hubble tension

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By Science Advisor, AAAS.  Excerpt: ...The rate of cosmic expansion, known as the Hubble constant, is so important for cosmologists that the disagreement among researchers over its value has its own name: the Hubble tension. Astronomers measure it one way, using stars or supernovae with predictable brightness. Cosmologists have another way, studying ripples in the echo of the Big Bang and winding the clock forward to today. The two techniques have become increasingly precise, but they steadfastly disagree with each other. A third method is needed to  break the deadlock  . That may come through the magic of gravitational lensing, which can cause a supernova—a star exploding at the end of its life—to appear to explode again and again. If a supernova is situated behind a large mass, such as a galaxy or cluster of galaxies, then as its light passes by the mass, its gravity bends the light along different paths, producing multiple images that show the explosion at different ti...
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Don’t Blink: The Vera C. Rubin Observatory Is Revolutionizing Astronomy.

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By Caryl-Sue Micalizio , Eos/AGU.  Excerpt: The  awe-inducing Vera C. Rubin Observatory  does not blink. From its sky-high altitude in the Chilean Andes, Rubin will image every point in the skies over the Southern Hemisphere 800 times over a 10-year period. The observatory is already issuing astronomers 800,000 alerts a night and eventually might send 10  million  a night. “The whole field of astronomy is about to be completely revolutionized by this dataset,” says astronomer Sarah Greenstreet in Kimberly Cartier’s beautiful, breathless introduction to the observatory, “ Small, Faint, or Fast, Rubin Will Find It .” So what is Rubin going to find? Asteroids . ...astronomers think Rubin might find 4 million more. Comets . Rubin’s unblinking eye will help astronomers trace comets and other trans-Neptunian objects in the icy reaches of the outer solar system. Planet 9 . “This is the survey that will determine whether Planet 9 is real or not,” says astronomer Meghan ...
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Lightning bolts on Jupiter pack more than 100 times the power of Earth’s flashes

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By Robert Sanders , UC Berkeley News.  Excerpt: Jupiter, the most massive planet in our solar system, has correspondingly humongous storms.... Some of these storms also generate terrific bolts of lightning, according to a new study by University of California, Berkeley scientists. Some flashes are 100 times more powerful than lightning on Earth — and possibly much stronger. The results come from analysis of data from NASA’s Juno spacecraft, which has been orbiting the planet since 2016 and scanning the atmosphere with its microwave radiometer, which can detect radio emissions from lightning similar to the radio interference created by lightning on Earth. ...lead author Michael Wong, a planetary scientist at UC Berkeley’s Space Sciences Laboratory...  study  was published March 20 in the journal  AGU Advances ....  Full article at https://news.berkeley.edu/2026/03/23/lightning-bolts-on-jupiter-pack-more-than-100-times-the-power-of-earths-flashes/ .  See also...
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Rocky, the Space Snowman

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By Science Insider.  Excerpt: Out past Neptune, connected spheres of rock orbit through the solar system like faceless galactic snowmen. Called contact binaries, these objects represent roughly 10% of all planetary building blocks. But how these cosmic curiosities form has remained unclear. Typically, simulations of two colliding space objects model the masses as fluid blobs that squish into a single sphere on impact. But using high-performance computers, ...new models were  able to predict the snowman-shaped contact binaries for the first time , scientists reported this week. As for the origins of the binaries, scientists think they began as single objects formed when gravity pulled together dust, gas, and pebbles in the disc of the early Milky Way. As the disc rotated, it ripped apart such objects into two separate chunks that orbited each other. Over time, gravity gently tugged these chunks back together until they fused into their characteristic two-lobed shape....  F...
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Why are Tatooine planets rare? Blame general relativity

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By Robert Sanders , UC Berkeley News.  Excerpt: Of the more than 4,500 stars known to have planets, one puzzling statistic stands out. Even though nearly all stars are expected to have planets and most stars form in pairs, planets that orbit both stars in a pair are rare. Of the more than 6,000 extrasolar planets, or exoplanets, confirmed to date — most of them found by NASA’s Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS) — only 14 are observed to orbit binary stars. There should be hundreds. Where are all the planets with two suns, like Tatooine in  Star Wars ? Astrophysicists at the University of California, Berkeley, and the American University of Beirut have now proposed a reason for this dearth of circumbinary exoplanets — and Einstein’s general theory of relativity is to blame. ...If a planet is orbiting the pair of stars, the gravitational tugs from the stars make the planet’s orbit precess, ...similar to the way the axis of a spinning top...
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