Universe Today

Gamma-ray bursts are some of the most powerful explosions in the Universe, briefly outshining the combined light of their entire galaxies. A team of astronomers has figured out a clever technique to use the light from gamma-ray bursts as bright lights that allow them to map out the large-scale structure of the Universe at different ages after the Big Bang. They found that the Universe might be less uniform at large scales than previously thought.

https://www.universetoday.com/articles/using-gamma-ray-bursts-to-probe-large-scale-structures

Helium-3 is a rare isotope emitted by the Sun, and it's very scarce in the Solar System. It's estimated that there's only one He3 atom for every 2,500 He4 atoms. But solar jets can boost the amount of He3 to 10,000 times its usual concentration. ESA's Solar Orbiter mission was recently bathed in He3, recording a 200,000-fold increase of the rare isotope because it was accelerated to higher speeds than other heavier elements by a jet emerging from a coronal hole.

https://www.universetoday.com/articles/a-hole-opened-up-in-the-suns-corona-and-vented-helium-3

Astronomers continue to study the mismatch in the expansion rates of the Universe at different times: the Hubble tension. There have been many possible explanations, from measurement errors to changing levels of dark energy. In a new paper, researchers propose a novel solution: that the Universe is slowly spinning. If the Universe rotated once every 500 billion years, that would change how space expands over time, explaining the speed mismatch.

https://www.universetoday.com/articles/an-interesting-solution-to-the-hubble-tension-the-universe-is-slowly-spinning

One of the most iconic images ever taken by Hubble is NGC 346 (M 104), also known as the Sombrero Galaxy. This is a beautiful galaxy seen nearly edge-on—just 6 degrees off—with its central bulge and a prominent outer disk. The central supermassive black hole contains 9 billion times the mass of the Sun; that's 2,000 times more massive than the Milky Way. Astronomers still haven't officially classified the Sombrero; it's just "peculiar" and awesome.

https://www.universetoday.com/articles/a-new-version-of-the-sombrero-galaxy-taken-by-hubble

Interferometry connects multiple telescopes into a single large telescope with higher resolution. It works on Earth, but an interferometer space telescope has always been a dream, with NASA's Terrestrial Planet Finder getting canceled decades ago. There's too much technical risk. A new research paper proposes a scaled-down, ultraprecision formation flying mission called SILVIA, which would test the key technology to enable future interferometer space telescopes.

https://www.universetoday.com/articles/its-time-to-build-a-space-telescope-interferometer-this-could-be-the-first-step

The Sun is a third-generation star, comprised not only of hydrogen and helium but of the additional metals created in previous generations of stars. But astronomers have found examples of stars with a fraction of the metals in the Sun, which they classify into different categories. The least metallic stars, designated "ultra metal-poor," have an iron to hydrogen ratio of 1/10,000th the Sun, giving a glimpse of what the first-ever stars might have looked like.

https://www.universetoday.com/articles/the-most-metal-poor-stars-are-living-fossils-from-the-beginning-of-the-universe

We know of a few thousand exoplanets, but very few are in the habitable zone, and none are perfect analogs for the Earth. But we will find some over time, eventually knowing of dozens of "other Earths." But what if we fail to find any obvious signs of life in the atmospheres of those worlds? According to a new paper, researchers predict that scanning 40-80 exoplanets and finding no life dramatically decreases our predictions for life in the Milky Way.

https://www.universetoday.com/articles/failing-to-find-life-tells-us-a-lot-about-life-in-the-universe

Supermassive black holes can emit powerful jets that stretch out into the cosmos, but the less massive stellar black holes can form jets too, generating beams of ionized gas that shoot outward at nearly the speed of light. Now, astronomers think they understand the underlying mechanism that generates these jets. They occur when the inner radius of the accretion disk suddenly decreases and reaches the closest point that matter can orbit without falling in.

https://www.universetoday.com/articles/how-black-holes-can-emit-powerful-jets

Thanks to JWST and other powerful observatories, astronomers are finding supermassive black holes earlier in the universe. The challenge is that actively feeding black holes will throw out a cloud of dust that obscures them from view. Now, researchers have developed a new technique that could reveal those hidden black holes. They've found that X-ray radiation emitted by infalling material heats the surrounding gas unusually high, providing a detectable signal.

https://www.universetoday.com/articles/a-new-technique-to-find-hidden-black-holes

You might be surprised to learn that greenhouse gas emissions can have an effect on the satellite carrying capacity of low Earth orbit. As more CO2 and other gases are pumped into the atmosphere, they cause the upper atmosphere to shrink, reducing atmospheric drag on existing satellites. Junk and defunct satellites will stay around longer before re-entering the atmosphere and burning up. Researchers estimate that carrying capacity could be reduced by more than 50%.

https://www.universetoday.com/articles/more-greenhouse-gases-means-less-room-for-satellites

Astrobiologists continue to struggle to find a single universal biosignature that could tell us if an exoplanet has life on it or not. Even if we could distinguish the chemicals of life from abiotic sources like volcanism, it still assumes that life will be similar to Earth-like life. A new paper proposes that missions search for "energy-ordered resource stratification," which only happens when both self-replication and ecological competition are present.

https://www.universetoday.com/articles/researchers-propose-a-new-way-to-search-for-evidence-of-life

Astronomers noticed a brief flash of radiation coming from a star a few years ago and deduced that it came from the star consuming a planet. But they weren't sure whether it was from the star bloating up as a red giant and engulfing the planet's orbit or the planet spiraling inward into the star. JWST to the rescue! Detailed observations from Webb showed the environment around the star didn't match a red giant - it was the planet crashing into the star.

https://www.universetoday.com/articles/webb-investigates-the-scene-of-a-planets-destruction

When galaxies run out of star-forming material, they get redder over time as the short-lived stars die, while the longer-lived dwarf stars can keep going for trillions of years. At least, that was the traditional thinking. But a new paper suggests that there could be redder galaxies that are still forming new stars. It's just that they're producing low-mass stars which start off red and stay red. This could mean that galactic life cycles are more complex than we thought.

https://www.universetoday.com/articles/red-galaxies-arent-necessarily-dead-galaxies

Future lunar explorers will hope to build permanent infrastructure on the Moon, using locally sourced ingredients, like regolith and water ice. Building materials will need to withstand the near vacuum of space, radiation, and micrometeoroid impacts. A team of researchers has developed "self-healing concrete," inspired by biological processes. It would contain bacteria that could regenerate themselves over time as the lunar environment wears them down.

https://www.universetoday.com/articles/promoting-substainable-lunar-bases-with-bio-concrete

While invisible dark matter and dark energy continue to confound astronomers, there's also the mystery of missing infrared light. Now a team of astronomers thinks they have found it. They examined a region of the sky using the Herschel Space Telescope, stacking 141 images, and found where individual dust-rich galaxies appeared blended together. The galaxies are absorbing starlight and re-emitting infrared radiation, accounting for the missing light.

https://www.universetoday.com/articles/astronomers-think-theyve-found-the-universes-missing-infrared-light

The surface of the Moon is bathed in radiation and suffers from dramatic changes in temperature. But there are places underground that could be fascinating to explore. In a new paper, researchers describe how snake-like rovers could crawl into subsurface environments on the Moon and explore them safely. The robotic snake would have solar panels that fold inside the body and then deploy outside when it's on the surface to bathe in the Sun and restore its batteries.

https://www.universetoday.com/articles/exploring-the-moon-with-subsurface-robots

The Small Magellanic Cloud is one of the closest galaxies to the Milky Way, visible to the unaided eye in the Southern Hemisphere. Researchers tracked the movements of 7,000 stars in the SMC and discovered that many are being pulled away towards the nearby Large Magellanic Cloud— the galaxy is being torn apart. This will eventually lead to the destruction of the SMC, as the tidal forces strip away its stars.

https://www.universetoday.com/articles/the-small-magellanic-cloud-is-being-torn-apart

CubeSats are the perfect platforms for studying Earth. They can pack a tremendous amount of sensors and computing into a very small, affordable package. A new paper looks into how CubeSats are being used for precision agriculture on Earth and how future applications could make this even better. Tiny satellites can resolve the Earth's surface at 3 meters per pixel, revealing details of plant health and growth, spotting pest outbreaks, and more for low costs to farmers.

https://www.universetoday.com/articles/flocks-of-cubesats-can-efficiently-monitor-farms

It's time for another comet alert: comet C/2025 F2 SWAN. It was first discovered on April 1st at 11th magnitude and has been increasing in brightness as it approaches the Sun. It will reach its closest point to the Sun on May 1st, coming just inside the orbit of Mercury, where it could be at its brightest. If it survives the solar flyby, it could reach magnitude 4, easily visible with the unaided eye. So, stay tuned.

https://www.universetoday.com/articles/new-comet-swan-could-put-on-a-brief-show-at-dawn

Enceladus is such a tantalizing place to search for life in the Solar System. Geysers of water ice are spewing out of its south pole and could contain the chemistry of life. The challenge, of course, is to directly sample it somehow. That's the goal of a recent study, where researchers investigate the pros and cons of an orbiter or flyby mission that could go directly through the plumes at Enceladus, sampling the material directly to scan for evidence of life.

https://www.universetoday.com/articles/the-search-for-biosignatures-in-enceladus-plumes