Astronomers spot first atmosphere around a potentially habitable alien world

By -
By Daniel Clery, Science. 

Excerpt: Astronomers have discovered more than 6000 planets orbiting other stars—many of them small and rocky like Earth. But despite years of searching, firm evidence that such worlds have stable atmospheres has remained elusive. Now, researchers report in Science that the relatively nearby super-Earth LHS 1140b appears to be leaking helium gas into space, implying it still has a substantial atmosphere billions of years after its birth. ...Many teams are zooming in on LHS 1140b, because of its many charms. Besides being nearby, it could be hiding other gases in its lower atmosphere, such as nitrogen and carbon dioxide—much like Earth. And if those gases provide an element of greenhouse warming, it could possess a liquid water ocean warm enough to swim in.... 


Popular posts from this blog

Early universe’s ‘little red dots’ may be black hole stars

By -
By Daniel Clery , Science.  Excerpt: It’s as if the baby universe had caught a case of measles. Since NASA’s JWST observatory began peering into the distant universe in 2022, it has discovered a rash of “little red dots”—hundreds of them, shining within the first billion years of the 13.8-billion-year-old universe, so small and red that they defied conventional explanation. Only in the past few months has a picture begun to emerge. The little red dots, astronomers say, may be an entirely new type of object: a colossal ball of bright, hot gas, larger than the Solar System, powered not by nuclear fusion, but by a black hole. ...JWST couldn’t resolve the dots into a recognizable shape, which meant they must have been tiny—less than 2% of the diameter of the Milky Way....  Full article at https://www.science.org/content/article/early-universe-s-little-red-dots-may-be-black-hole-stars . 
Read more

Planet-Eating Stars Hint at Earth’s Ultimate Fate

By -
By Matthew R. Francis , Eos/AGU.  Excerpt: Our Sun is about halfway through its life, which means Earth is as well. After a star exhausts its hydrogen nuclear fuel, its diameter expands more than a hundredfold, engulfing any unlucky planets in close orbits. That day is at least 5 billion years off for our solar system, but scientists have spotted a possible preview of our world’s fate. Using data from the  TESS (Transiting Exoplanet Survey Satellite) observatory , astronomers  Edward Bryant  of the University of Warwick and  Vincent Van Eylen  of University College London compared systems with stars in the main sequence of their lifetimes—fusing hydrogen, like the Sun—with post–main sequence stars closer to the end of their lifetimes, both with and without planets. “We saw that these planets are getting rarer [as stars age],” Bryant said. In other words,  planets are disappearing as their host stars grow old . The comparison between planetary systems w...
Read more

This ‘Galaxy That Wasn’t’ Never Bore Any Stars

By -
By Katrina Miller , The New York Times.  Excerpt: This week, astronomers announced the discovery of a new kind of cosmic object, something that is very nearly a galaxy, save for one crucial, missing ingredient: stars. The almost-galaxy is about 14 million light-years from Earth. It was the ninth cloud found to be associated with a nearby spiral galaxy, leading to its serendipitous name: Cloud-9. The object is starless, consisting of only a haze of hydrogen gas that astronomers believe is swaddled in a much more massive clump of  dark matter,  the invisible substance that permeates the cosmos and shapes its overarching structure. ...Cloud-9 is the first confirmed example of what astronomers call a RELHIC, short for Reionization-Limited H I Cloud and pronounced “relic.” Such objects are rich in gaseous hydrogen but devoid of any stars. They are  failed galaxies  thought to be nearly as old as time itself, primordial fossils that can help astronomers understand the...
Read more