A new analysis of how galaxy clusters evolved over the 13.8-billion-year history of the cosmos could help solve a long-standing tension surrounding the ‘lumpiness’ of our universe’s matter content. Down the line, it may also help scientists solve a host of other cosmic mysteries. The first data from the eROSITA all-sky survey of cosmic X-ray sources, which completed 4.5 full sky surveys in February of 2022, contained precision measurements of both the amount of total matter in the universe and the matter’s level of smoothness, or “homogeneity.” These findings could…
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Our universe is merging with ‘baby universes’, causing it to expand, new theoretical study suggests
Our universe is expanding at an ever-accelerating rate — a phenomenon that all theories of cosmology agree upon but none can fully explain. Now, a new theoretical study offers an intriguing solution: Perhaps our universe is expanding because it keeps colliding with and absorbing “baby” parallel universes. Studies of the cosmic microwave background, the afterglow of the Big Bang, have revealed that our universe is experiencing accelerated expansion. For this observation to fit with the main theory of cosmic evolution — called the Standard Cosmological Model — physicists assume that…
Read MoreDiscovery Alert: Glowing Cloud Points to a Cosmic Collision
3 min read Discovery Alert: Glowing Cloud Points to a Cosmic Collision This illustration depicts the aftermath of a collision between two giant exoplanets. What remains is a hot, molten planetary core and a swirling, glowing cloud of dust and debris. Mark A. Garlick The Discovery: A glowing cosmic cloud has revealed a cataclysmic collision. Key Facts: Even within our own solar system, scientists have seen evidence of giant, planetary collisions from long ago. Remaining clues like Uranus’ tilt and the existence of Earth’s moon point to times in our…
Read MoreSpiral Galaxy NGC 4254’s Dazzling Swirls
It’s oh-so-easy to be mesmerized by this spiral galaxy. Follow its clearly defined arms, which are brimming with stars, to its center, where there may be old star clusters and – sometimes – active supermassive black holes. NASA’s James Webb Space Telescope delivered highly detailed scenes of this and other nearby spiral galaxies in a combination of near- and mid-infrared light. NASA, ESA, CSA, STScI, Janice Lee (STScI), Thomas Williams (Oxford), and the PHANGS team NGC 4254, a spiral galaxy, is resplendent in orange and blue in this Jan. 29,…
Read MoreOrbital resonance — the striking gravitational dance done by planets with aligning orbits
Planets orbit their parent stars while separated by enormous distances – in our solar system, planets are like grains of sand in a region the size of a football field. The time that planets take to orbit their suns have no specific relationship to each other. But sometimes, their orbits display striking patterns. For example, astronomers studying six planets orbiting a star 100 light years away have just found that they orbit their star with an almost rhythmic beat, in perfect synchrony. Each pair of planets completes their orbits in…
Read MoreHubble Spots a Galaxy Shrouded by Stars
2 min read Hubble Spots a Galaxy Shrouded by Stars This Hubble image shows irregular galaxy, ESO 245-5, located some of 15 million light-years from Earth. ESA/Hubble & NASA, M. Messa This NASA/ESA Hubble Space Telescope image shows a densely packed field of stars laid upon a background of dust, gas, and light from more distant celestial objects. There are so many stars in this image’s field of view that it may be a little tricky to discern that you are in fact looking at a galaxy. Known as ESO…
Read MoreNASA’s Hubble Traces ‘String of Pearls’ Star Clusters in Galaxy Collisions
3 min read NASA’s Hubble Traces ‘String of Pearls’ Star Clusters in Galaxy Collisions Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, seen in this NASA Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. They form when knots of gas gravitationally collapse to create about 1 million newborn stars per cluster. NASA, ESA, STScI,…
Read MoreDark matter could be gently wobbling space-time around us — and scientists may finally know how to detect it
Scientists may soon be able to detect the most mysterious entity in the universe using a fleet of next-generation satellites, a new theoretical study suggests. Dark matter — a poorly understood substance that does not emit, absorb or reflect light but exerts a clear gravitational influence on other matter — dominates the universe. Despite being more than five times more abundant in space than ordinary matter, dark matter’s composition and properties remain entirely unknown. To address this problem, Hyungjin Kim a theoretical physicist at the German Electron Synchrotron (DESY) accelerator center, proposed searching…
Read MoreWhat is Dark Energy? Inside our accelerating, expanding Universe
11 min read What is Dark Energy? Inside our accelerating, expanding Universe Some 13.8 billion years ago, the universe began with a rapid expansion we call the big bang. After this initial expansion, which lasted a fraction of a second, gravity started to slow the universe down. But the cosmos wouldn’t stay this way. Nine billion years after the universe began, its expansion started to speed up, driven by an unknown force that scientists have named dark energy. But what exactly is dark energy? The short answer is: We don’t…
Read MoreWhat’s Made in a Thunderstorm and Faster Than Lightning? Gamma Rays!
3 min read What’s Made in a Thunderstorm and Faster Than Lightning? Gamma Rays! A flash of lightning. A roll of thunder. These are normal stormy sights and sounds. But sometimes, up above the clouds, stranger things happen. Our Fermi Gamma-ray Space Telescope has spotted bursts of gamma rays – some of the highest-energy forms of light in the universe – coming from thunderstorms. Gamma rays are usually found coming from objects with crazy extreme physics like neutron stars and black holes. So why is Fermi seeing them come from thunderstorms? About a thousand times a…
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