Browsed by
Category: Astronomy

Planet-eating stars hint at hidden chaos in the Milky Way

Planet-eating stars hint at hidden chaos in the Milky Way

Nature reports: Stellar detectives have identified seven stars that recently dined on a rocky planet. The study doubles the number of binary stars known to have consumed a planet, and questions the perception that mature solar systems harbouring Earth-like planets are usually stable. The findings, published in Nature on 20 March, show “strong evidence of planet ingestion”, says Jianrong Shi, an astronomer at the National Astronomical Observatories in Beijing. The planets seem to have been eaten during their stars’ relatively…

Read More Read More

Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Do black holes explode? The 50-year-old puzzle that challenges quantum physics

Davide Castelvecchi writes: In hindsight, it seems prophetic that the title of a Nature paper published on 1 March 1974 ended with a question mark: “Black hole explosions?” Stephen Hawking’s landmark idea about what is now known as Hawking radiation1 has just turned 50. The more physicists have tried to test his theory over the past half-century, the more questions have been raised — with profound consequences for how we view the workings of reality. In essence, what Hawking, who…

Read More Read More

We finally know what turned the lights on at the dawn of time

We finally know what turned the lights on at the dawn of time

Science Alert reports: We finally know what brought light to the dark and formless void of the early Universe. According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic dawn were small dwarf galaxies that flared to life, clearing the fog of murky hydrogen that filled intergalactic space. “This discovery unveils the crucial role played by ultra-faint galaxies in the early Universe’s evolution,” says astrophysicist Iryna Chemerynska of the…

Read More Read More

JWST finds ancient galaxy larger than our Milky Way, and it’s threatening to upend cosmology

JWST finds ancient galaxy larger than our Milky Way, and it’s threatening to upend cosmology

Live Science reports: The James Webb Space Telescope (JWST) has found a galaxy in the early universe that’s so massive, it shouldn’t exist, posing a “significant challenge” to the standard model of cosmology, according to the study authors. The galaxy, called ZF-UDS-7329, contains more stars than the Milky Way, despite having formed only 800 million years into the universe’s 13.8 billion-year life span. This means they were somehow born without dark matter seeding their formation, contrary to what the standard…

Read More Read More

Several ingredients for life found on Enceladus, a small moon of Saturn

Several ingredients for life found on Enceladus, a small moon of Saturn

The New York Times reports: Scientists have detected a poison among the spray of molecules emanating from a small moon of Saturn. That adds to existing intrigue about the possibility of life there. The poison is hydrogen cyanide, a colorless gas that is deadly to many Earth creatures. But it could have played a key role in chemical reactions that created the ingredients that set the stage for the advent of life. “It’s the starting point for most theories on…

Read More Read More

Could the universe be finite?

Could the universe be finite?

Eric Schwitzgebel and Jacob Barandes write: On recent estimates, the observable universe—the portion of the universe that we can detect through our telescopes—extends about 47 billion light-years in every direction. But the limit of what we can see is one thing, and the limit of what exists is quite another. It would be remarkable if the universe stopped exactly at the edge of what we can see. For one thing, that would place us, surprisingly and un-Copernicanly, precisely at the…

Read More Read More

Scientists discover rare 6-planet system that moves in strange synchrony

Scientists discover rare 6-planet system that moves in strange synchrony

University of Chicago reports: Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat. The planets move in an orbital waltz that repeats itself so precisely it can be readily set to music. A rare case of an “in sync” gravitational lockstep, the system could offer deep insight into planet formation and evolution. The analysis, led by UChicago scientist Rafael Luque, was published Nov. 29 in Nature. “This discovery…

Read More Read More

Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Live Science reports: The supermassive black hole at the heart of our galaxy isn’t just spinning — it’s doing so at almost maximum speed, dragging anything near it along for the ride. Physicists calculated the rotational speed of the Milky Way’s supermassive black hole, called Sagittarius A* (Sgr A*), by using NASA’s Chandra X-ray Observatory to view the X-rays and radio waves emanating from outflows of material. The spin speed of a black hole is defined as “a” and given…

Read More Read More

‘Teenage’ galaxies from the early universe contain mysterious heavy elements, James Webb telescope reveals

‘Teenage’ galaxies from the early universe contain mysterious heavy elements, James Webb telescope reveals

Live Science reports: The deeper we look into space, the further back in time we see. Light emanating from some of the younger galaxies in our universe has to travel for billions of years to reach us, getting picked up by our instruments, rich with information from the cosmic dawn. And not only can this light tell us where we have come from, but where we might be headed. To understand the evolution of several of these early universe, “teenage”…

Read More Read More

Supernovae blasts struck the Earth 3 million and 7 million years ago

Supernovae blasts struck the Earth 3 million and 7 million years ago

Universe Today reports: A recent study examines how the Earth was hit by blasts from supernovae (plural form of supernova (SN)) that occurred 3 million years ago (Mya) and 7 Mya with the goal of ascertaining the distances of where these blasts originated. Using the live (not decaying) radioactive isotope 60-Fe, which is produced from supernovae, a team of researchers at the University of Illinois was able to determine the approximate astronomical distances to the blasts, which they refer to…

Read More Read More

How NASA brought an asteroid to Earth

How NASA brought an asteroid to Earth

David W. Brown writes: On a brisk day in February, 2004, Dante Lauretta, an assistant professor of planetary science at the University of Arizona, got a call from Michael Drake, the head of the school’s Lunar and Planetary Laboratory. “I have Lockheed Martin in my office,” Drake said. “They want to fly a spacecraft to an asteroid and bring back a sample. Are you in?” The two men met that evening with Steve Price, then a director of business development…

Read More Read More

Our galaxy’s stars keep a record of its past

Our galaxy’s stars keep a record of its past

Rebecca Boyle writes: Late in the evening of October 5, 1923, Edwin Hubble sat at the eyepiece of the Hooker telescope at the Mount Wilson Observatory, atop the mountains overlooking the Los Angeles basin. He was observing an object in the northern sky. To the unaided eye, it was visible as a faint smudge. But through a telescope it sharpened into a brilliant ellipse called the Andromeda Nebula. To settle a debate about the size of the Milky Way —…

Read More Read More

Don’t expect a ‘theory of everything’ to explain everything

Don’t expect a ‘theory of everything’ to explain everything

Dennis Overbye writes: What good are the laws of physics if we can’t solve the equations that describe them? That was the question that occurred to me on reading an article in The Guardian by Andrew Pontzen, a cosmologist at University College London who spends his days running computer simulations of black holes, stars, galaxies and the birth and growth of the universe. His point was that he and the rest of us are bound to fail. “Even if we…

Read More Read More

Back to New Jersey, where the universe began

Back to New Jersey, where the universe began

Dennis Overbye writes: On a field just below the summit of Crawford Hill, the highest point in Monmouth County, N.J., almost within sight of the skyscrapers of Manhattan, sits a cluster of shacks and sheds. Next to them is the Holmdel Horn Antenna, a radio telescope somewhat resembling the scoop of a giant steam shovel: an aluminum box 20 feet square at the mouth and tapering to an eight-inch opening, through which the radio waves are funneled into the “cab,”…

Read More Read More

Will the universe ever stop expanding?

Will the universe ever stop expanding?

Sarah Scoles writes: From Earth, the night sky looks fairly static. Sure, the stars rotate from evening to evening, and the planets move among them. But from a terrestrial perspective, the celestial sphere appears essentially unchanging. Perception, though, is not reality: our eyeballs don’t hint that beyond nearby planets, stars and galaxies, everything is moving away from us. The universe is constantly expanding—at an ever faster rate. “When we say that the universe is expanding, we mean something pretty literal,”…

Read More Read More

Is there a crisis in cosmology?

Is there a crisis in cosmology?

Adam Frank and Marcelo Gleiser write: Not long after the James Webb Space Telescope began beaming back from outer space its stunning images of planets and nebulae last year, astronomers, though dazzled, had to admit that something was amiss. Eight months later, based in part on what the telescope has revealed, it’s beginning to look as if we may need to rethink key features of the origin and development of the universe. Launched at the end of 2021 as a…

Read More Read More