Phil Plait writes: How dark is dark? When you go outside on a clear, moonless night, you can see not only lots of stars but also the black space between them—literally space, in this case. Given that you can see stars and that the sky is black, you might think the sky is transparent. But it’s not—at least, not really. Various molecules, atoms and particulates float around in the air, and these reflect light. During the day, sunlight entering the…
Universe Today reports: Earth’s average global temperatures have been steadily increasing since the Industrial Revolution. According to the National Oceanic and Atmospheric Agency (NOAA), Earth has been heating up at a rate of 0.06 °C (0.11 °F) per decade since 1850 – or about 1.11 °C (2 °F) in total. Since 1982, the average annual increase has been 0.20 °C (0.36 °F) per decade, more than three times as fast. What’s more, this trend is projected to increase by between 1.5 and 2 °C…
Science Alert reports: If you travel far enough away from the Sun, the Solar System becomes a lot more populated. Out past the orbit of Neptune lies the Kuiper Belt, a vast, ring-shaped field of icy rocks. This is where Pluto resides, and Arrokoth, and countless other small objects in the cold and the dark. These are known as Kuiper Belt objects or KBOs, and astronomers have just found hints of an unexpected rise in their density, between 70 and…
Science News reports: The biggest clash in cosmology might be inching closer to resolution, thanks to the James Webb Space Telescope. Scientists disagree over the universe’s expansion rate, known as the Hubble constant. There are two main methods for measuring it — one based on exploding stars called supernovas and the other on the universe’s oldest light, the cosmic microwave background. The two techniques have been in conflict for a decade, in what’s known as the “Hubble tension.” If this…
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 —…
Phil Plait writes: Polaris, the North Star, is one of the most famous stars in the sky, but it’s also quite an enigma. A recent reappraisal of its basics—such as its mass and distance from Earth—suggests that the star is paradoxically youthful, appearing to be only a small fraction of its true multi-billion-year age, like a middle-aged human who somehow passes for a toddler. This is deeply strange; you’d probably assume astronomers have simply miscalculated this star’s age. But in…
Quartz reports: Some stars in our very own Milky Way are some of the earliest ever seen, according to research published today in the Monthly Notices of the Royal Astronomical Society. The stars are in the Milky Way’s halo, a shroud of stars that surrounds the galactic disk. The stars are also relatively close, at just 30,000 light-years from Earth. The team found that the stars are between 12 billion and 13 billion years old, clocking them to around the…
The universe as a network of rivers: This remarkable new map reveals how galaxies flow like water, following the pull of gravity across hundreds of millions of light years. https://t.co/krsqjnnoa3 pic.twitter.com/192Q28SrM9 — Corey S. Powell (@coreyspowell) April 26, 2024 Astrobites reports: Cosmography is the science of cartography, but applied to the Universe by mapping out the Large Scale Structures such as voids, filaments and superclusters. While galaxy surveys are able to create such maps from just looking at spatial information…
NASA reports: For the first time since November, NASA’s Voyager 1 spacecraft is returning usable data about the health and status of its onboard engineering systems. The next step is to enable the spacecraft to begin returning science data again. The probe and its twin, Voyager 2, are the only spacecraft to ever fly in interstellar space (the space between stars). Voyager 1 stopped sending readable science and engineering data back to Earth on Nov. 14, 2023, even though mission…
The European Space Agency reports: Wading through the wealth of data from ESA’s Gaia mission, scientists have uncovered a ‘sleeping giant’. A large black hole, with a mass of nearly 33 times the mass of the Sun, was hiding in the constellation Aquila, less than 2000 light-years from Earth. This is the first time a black hole of stellar origin this big has been spotted within the Milky Way. So far, black holes of this type have only been observed…
Marina Koren writes: Cosmically speaking, the alignment of Earth, the sun, and the moon is ordinary. But from our corner of the universe, the occurrence produces something wondrous: a total solar eclipse. On April 8, the moon will pass between the sun and Earth, casting a shadow along a narrow strip of the country, from Texas to Maine. Outside this path, the sun will not disappear, and the best and safest way to observe the event is with eclipse glasses….
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…
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…
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…
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…
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…