Flybys of primordial black holes may occur once a decade. Tweaks to the orbits of planets and GPS satellites could give away their presence ..read more

Different measurements of the cosmic expansion rate disagree. The James Webb telescope could determine whether that disagreement is real ..read more

A new look at how light bends as it travels through the universe could point to an alternative theory of gravity ..read more

A year of data from DESI, the Dark Energy Spectroscopic Instrument, suggests that, contrary to expectations, dark energy might vary over time ..read more

Reports that NASA’s James Webb Space Telescope broke the universe may have been exaggerated. In its first images, JWST captured what appeared to be gargantuan galaxies in the early universe — ones much too big to be explained by current cosmological theories (SN: 2/22/23). But a new analysis of old data from the Hubble Space Telescope suggests that those alleged behemoths probably have more prosaic explanations fitting in with our standard understanding of the universe, cosmologist Julian Muñoz and colleagues report in the Feb. 9 Physical Review Letters. “James Webb is giving us a new dictiona ..read more

The greatest puzzle in cosmology just got even more puzzling. Images from the James Webb Space Telescope have confirmed that the universe appears to be expanding significantly faster than it should be, researchers report in a study accepted in the Astrophysical Journal. The observation is in conflict with an esteemed theory, the standard model of cosmology, that describes how the universe has evolved since the first moments after the Big Bang. The conflict comes down to calculations of the Hubble constant, a number that describes how fast everything in the universe is flying apart. One calcula ..read more

When Brant Robertson saw a new measurement of the distance to a familiar galaxy, he laughed out loud. For more than a decade, the galaxy had been a contender for the most distant ever observed. In 2012, Robertson and colleagues used data from the Hubble Space Telescope to show that the galaxy’s light had shone across the universe from about 13.3 billion years ago — less than 400 million years into the universe’s existence. Not everyone believed it. “We got a lot of flak,” recalls Robertson, an astrophysicist at the University of California, Santa Cruz. “It seemed too implausible that it was at ..read more

The James Webb Space Telescope has spotted objects in the early universe that might be a new kind of star — one powered by dark matter. These “dark stars” are still hypothetical. Their identification in JWST images is far from certain. But if any of the three candidates — reported in the July 25 Proceedings of the National Academy of Sciences — turn out to be this new type of star, they could offer a glimpse of star formation in the early universe, hint at the nature of dark matter and possibly explain the origins of supermassive black holes. First proposed in 2007 by cosmologist Katherine Fre ..read more

There was a secret inside the envelope in the hands of Stephan Schlamminger, one of the world’s leading experts in experimental tests of gravity. He appeared to be on the verge of opening the envelope during a presentation at the April 2022 meeting of the American Physical Society, to read a number that would reveal whether his latest efforts in a lifelong passion had been a success. Schlamminger, of the National Institute of Standards and Technology in Gaithersburg, Md., sought to measure Newton’s gravitational constant. The secret number in the envelope was a kind of code — an intentional an ..read more

For the first time, astronomers have caught a glimpse of shock waves rippling along strands of the cosmic web — the enormous tangle of galaxies, gas and dark matter that fills the observable universe. Combining hundreds of thousands of radio telescope images revealed the faint glow cast as shock waves send charged particles flying through the magnetic fields that run along the cosmic web. Spotting these shock waves could give astronomers a better look at these large-scale magnetic fields, whose properties and origins are largely mysterious, researchers report in the Feb. 17 Science Advances. F ..read more