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If scientists discover aliens, they have a plan for ‘disclosure day’

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By Daniel Clery , Science.  Excerpt: Disclosure Day , arriving in movie theaters this week, deals with what would be a pivotal event in history: the moment conclusive evidence arrives of intelligent life elsewhere in the universe. The movie pits sinister military-industrial forces that hide and control the information against those who strive to reveal the truth. ...Researchers involved in the search for extraterrestrial intelligence (SETI) have long realized this moment—if it ever arrives outside cinemas—is going to be fraught with emotion, confusion, and possible danger. To get a jump on such events, the International Academy of Astronautics (IAA) convened a permanent committee of SETI experts. In 1989, the committee drew up a set of “postdetection protocols,” nonbinding guidelines for what scientists and their institutions should do when the time comes. The protocols stress the importance of verifying the alien signal and making accurate and transparent announcements. They sugge...
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Radical proposal would block solar storms with orbital ‘airbag’

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By Paul Voosen , Science.  Excerpt: When violent eruptions from the Sun slam into Earth’s magnetic field, they do more than paint aurorae across the night sky. They can scramble the electronics of satellites and induce powerful ground currents that knock out electrical grids. It’s been estimated that a one-in-a-100-year solar storm like the 1859 Carrington Event could cause more than $3 trillion of damage to the power grid alone. ...In a study published today in Space Weather , the researchers describe a provocative proposal called “StormWall”: a fleet of satellites that would release hundreds of tons of gases into space just before a solar storm strikes Earth. Computer simulations suggest the artificial cloud could cut the intensity of a major solar storm by half or more....  Full article at https://www.science.org/content/article/radical-proposal-would-block-solar-storms-orbital-airbag . 
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Tiny 500-km-wide ‘plutino’ has an atmosphere it shouldn’t

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By ScienceAdvisor.  Excerpt: Most small worlds in the outer Solar System are not expected to have atmospheres. Gas escapes too easily, and there is little to replace it. Pluto, larger and rich in ices that can vaporize into gas, has long been the only known exception. Now,  astronomers have spotted a thin atmosphere around a much smaller object . Known as 2002 XV93, it’s a distant plutino, a Kuiper Belt object ...described in a new paper in  Nature Astronomy . At roughly 250 kilometers in radius, it falls far below the size thought necessary to sustain an atmosphere. But in January 2024, as the object passed in front of a distant star, astronomers noticed something unusual: The starlight did not vanish all at once, but instead dimmed gradually. That subtle fade is the telltale signature of an atmosphere. ...By modeling the signal, researchers estimated a surface pressure of about 100 to 200 nanobars, tens of times thinner than Pluto’s atmosphere, but far denser than expec...
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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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