Rubin observatory begins a 10

Last night, the Vera C. Rubin Observatory began to film the greatest time-lapse movie ever made: a 10-year record of the changing night sky. Over a few nights, the telescope will sweep the entire hemisphere of sky visible from its Chilean mountaintop with the largest digital camera ever built, then do it again and again for a decade. In its first year the survey will generate more data than all previous optical telescopes combined. It will capture everything from wandering asteroids and exploding stars to the growth of distant galaxies, and it will spew the data continuously to the world’s astronomers. Rubin opened its giant eye on the universe a little over a year ago, releasing its first images in June 2025. Since then, engineers have been fine-tuning the observatory to run with a relentless, factorylike regularity, sweeping the sky night after night without interruption. “It’s remarkable how much effort is needed from so many people to make everything work right,” says astronomer Eric Bellm of the University of Washington (UW), science lead of Rubin’s system for notifying astronomers whenever the telescope spots something new or changing. “Seeing that come together and actually being able to start the survey is just hugely exciting.” Built by the U.S. National Science Foundation and the Department of Energy, the $800 million Rubin was designed to roam the sky rather than respond to astronomers’ requests to stare intently at one spot. Its 8.4-meter mirror captures a patch of sky 45 times the size of the full Moon, while its car-size, 3200-megapixel camera can slew to the next area of sky in seconds and take up to 1000 images each night, generating 20 terabytes of data. Whenever an asteroid streaks by, a star explodes, or a distant object brightens or fades, Rubin will issue an alert in little more than a minute so astronomers can rapidly follow up. Eventually, it is expected to produce 10 million alerts per night. At the same time, researchers will “stack” years of images to create a deep, detailed cosmic map of 200 million stars in and around the Milky Way and 20 billion distant galaxies. The map will allow astronomers to probe the distribution of unseen dark matter, around which galaxies coalesce, and trace how mysterious dark energy has accelerated the expansion of the cosmos. Even before the survey began, Rubin tantalized astronomers. Its first images revealed 2000 new asteroids. A team led by Sarah Greenstreet of UW jumped on the data and showed a handful were “ultrafast rotators,” with one turning every 1.9 minutes—“the fastest spinning large asteroid that has been found to date,” Greenstreet says. Rubin is expected to find millions more, including 90,000 new near-Earth objects, which could potentially threaten the planet. Rubin could catch a glimpse of a proposed large planet beyond Neptune, Planet 9, first suggested in 2016 from its gravitational effects on other objects’ orbits. “A direct image would be an awesome end to the saga,” says Konstantin Batygin of the California Institute of Technology. The early data also hinted at Rubin’s prowess for finding more distant transients. Igor Andreoni of the University of North Carolina at Chapel Hill and his colleagues found eight supernovae candidates along with unusually distant novae—eruptions from dead stars that gain fresh material. “That really opened our minds to this new norm,” Andreoni says. “We’re finding novae … 10 or 20 times further than we’re used to.” In November 2025, Rubin joined a chase after a highly unusual gravitational-wave alert. Detectors had picked up space-time ripples from the merger of two compact objects, one of which appeared to have less mass than the Sun—too small, theorists say, to be a black hole or neutron star. A handful of telescopes started to hunt for an optical counterpart of the event, and Rubin joined in. None of the almost 250 candidates survived further scrutiny, and the subsolar object remains a mystery. Still, “The Rubin data was great because it was much deeper, so it could see things much fainter than the other telescopes,” says Noah Franz, an astronomer at the University of Arizona who studied the candidates. The cosmic map will emerge more slowly. “The first year of data is not going to be great for faint stuff, but as they build up the data over 10 years, it gets better and better,” says Aaron Romanowsky of San José State University. Already, he and his colleagues used the early data to find a candidate ultradiffuse galaxy, one in a class of dim, ghostly galaxies that astronomers suspect are hiding throughout the universe. Because some appear to be dominated by dark matter whereas others seem to contain almost none, how they form has become a big puzzle in galaxy evolution. The deep observations will uncover countless more galaxies, helping astronomers tease apart how they form over cosmic time. Spanning much of the universe’s history, they will also help chart the tug of war between dark matter and dark energy as the universe grew. Sandrine Thomas, the associate director who led the on-site team that prepared the telescope for showtime, says the science done so far is “very exciting.” “That’s why we can’t hold those data that much longer,” she says. With the cameras finally rolling, Bellm is looking forward to seeing how the story unfolds. “The headline discoveries are still to come,” he says.