Universe Today

Solar sails are space's ultimate free ride, they get their propulsion from the Sun, so they don't need to carry propellant, but they come with their own challenges. A sail has a large surface area but a low mass, which creates a huge moment of inertia and makes it difficult to control, especially with reaction wheels. A team of engineers have cracked it though with "smart mirrors" that can instantly switch their reflectivity on command, transforming sunlight from an unruly force into a precision steering tool.

The early universe was shrouded in darkness. Just hundreds of millions of years after the Big Bang, a thick fog of hydrogen gas choked the cosmos, blocking light from traveling far. At some point, this gas became ionized, stripped of its electrons. Thanks to the James Webb Space Telescope, astronomers have identified the culprit: low-mass starburst galaxies emitting huge amounts of ultraviolet light. In just one patch of sky. They discovered 83 of these galactic powerhouses in one part of the sky at a time when the Universe was only 800 million years old.

An international team of astronomers using the [*Cosmology Large Angular Scale Surveyor*](https://sites.krieger.jhu.edu/class/) (CLASS) [reported the first-ever measurement](https://hub.jhu.edu/2025/06/11/telescopes-look-at-cosmic-dawn/) announced the first-ever detection of radiation from the cosmic microwave background (CMB) interacting with the first stars in the Universe.

We don't know what dark matter is, but that doesn't stop astronomers from using it to their advantage. Dark matter is part of what makes gravitational lensing so effective. Astronomers expect the Roman Space Telescope to find 160,000 gravitational lenses, and dark matter makes a crucial contribution to these lenses.

When astronauts finally reach Mars, they'll face a unique challenge: walking and working in gravity that's only 37% as strong as Earth's. After spending months in the weightlessness of space, their weakened muscles and bones will struggle to cope with even this reduced gravity. Now, researchers at the University of Bristol have developed a promising solution; a soft, wearable exosuit powered by inflatable "bubble muscles."

When the Apollo astronauts landed on the Moon, they discovered drifts of tiny brilliant orange glass beads glittering across the surface. Each one less than 1 mm across and formed about 3.6 billion years ago. These microscopic treasures, each smaller than a pinhead, had been hiding their secrets for billions of years. Now, cutting edge technology has finally cracked the mystery: they're perfect time capsules from the Moon's explosive volcanic past, frozen droplets of ancient lava that solidified instantly in the airless void recording the history of the Moon.

The Hubble Deep Field revolutionised astronomy by staring at a seemingly empty patch of sky for thousands of hours, unveiling a cosmos teeming with distant galaxies. But even Hubble can't peer back far enough to witness the universe's first moment of illumination; the Cosmic Dawn, when primordial darkness gave way to starlight. Now, the Square Kilometre Array promises to shatter that barrier. In a groundbreaking simulation, researchers have modelled 1000 hours of SKA observations, creating astronomy's next great deep field, one designed to capture the universe's very first sunrise.

The ecliptic is the apparent path that the Sun follows during a year. It's an imaginary line that the planets follow, with some small deviations, around the Sun. Spacecraft find it easier to follow the ecliptic because it's generally more energy efficient. However, the Solar Orbiter isn't on the ecliptic and it's giving us our first up-close looks at the Sun's poles.

For most of us, dust is just something we have to clean up. For astronomers, interstellar dust is a hindrance when they want to study distant objects. However, recent James Webb Space Telescope (JWST) observations of a distant galaxy are changing that. This infrared-sensitive observatory is letting them find a way to use dust to understand the evolution of early galaxies. In addition, it uncovered a special property of that galaxy's ice-covered dust, indicating it could be similar to the materials that formed our Solar System.

Most scientists agree that supernova explosions have affected Earth's climate, though the details are not all clear. They likely cooled the climate several times in the last several thousand years, just as humanity was becoming established around the world. The evidence is in telescopes and tree rings.

Astronomers have used JWST to study a fascinating planetary system that's only 16.7 million years old, with two bizarre giant exoplanets. Designated YSES-1, its closer planet, YSES-1b seems to be surrounded by a disk of material that could be the birthplace of moons, similar to what might have happened at Jupiter billions of years ago. The other, YSES-1c, has a layer of silicate particles in its upper atmosphere—clouds of sand.

Astronomers have discovered the site of a newly forming exoplanet, probably with several times the mass of Jupiter. The image was captured by ESO's Very Large Telescope, seeing the young star system 2MASS 1612 in infrared light. The disk extends about 130 astronomical units from the star, but you can see a bright ring followed by a gap at about 50 AU. It's believed there's a new planet forming in that gap, pulling in material from the disk of gas and dust around it.

As worldwide temperatures continue to rise and conventional solutions aren't working fast enough, governments may turn to geoengineering solutions. One idea is to place a giant sunshade somewhat like an umbrella between the Earth and the Sun to block some of the sunlight that reaches our planet. A new mission proposes sending an 81 m² sail to Earth-Sun L1 to measure the effect of blocking a tiny fraction of solar energy.

When the Sun rages and storms in Earth's direction, it changes our planet's atmosphere. The atmosphere puffs up, meaning satellites in Low-Earth Orbit (LEO) meet more resistance. This resistance creates orbital decay, dragging satellites to lower altitudes. One researcher says we can change the design of satellites to decrease their susceptibility.

Gas clouds in the Milky Way's Galactic Center contain copious amounts of star-forming gas. But for some reason, few massive stars form there, even though similar gas clouds elsewhere in the galaxy easily form massive stars. The clouds also form fewer stars overall. Are they a new type of molecular cloud?

About 3 billion years after the Big Bang, star formation exploded across the cosmos. During the era dubbed "cosmic noon.” It was also when galaxies and supermassive black holes were growing faster than at any other time in the history of the universe. Now astronomers have discovered a monster from this frenzied period: a supermassive black hole unleashing jets that stretch over 300,000 light-years into space, revealing the sheer violence of its feeding frenzy.

How can radio astronomers successfully identify extraterrestrial radio signals while discerning them from Earth-based radio signals? This is what a recent study published in The Astronomical Journal hopes to address as a team of researchers investigated how machine learning could be used to search for extraterrestrial technosignatures while simultaneously identifying radio contamination from human radio signals. This study has the potential to help radio astronomers develop more efficient methods in searching for and identifying radio signals from extraterrestrial civilizations.

Most exoplanets have been detected indirectly through the transit or radial velocity method. But here's an image of the exoplanet 14 Herculis c captured by Webb. It has been described as a "chaotic" and "abnormal" planetary system and is about 7 Jupiter masses, but with a surface temperature of only -3°C. The discovery offers new insights into how planetary systems can develop in dramatically different ways from our own Solar System.

Astronomers recently used a pair of powerful telescopes to zero in on a cosmic battle going on some 11 billion light-years away from us. The combatants are a pair of galaxies charging at each other over and over again, at velocities upwards of 500 kilometers per second. According to one of the scientists studying the scene, one galaxy is cutting into the heart of the other with a blast of radiation.

NASA's 2001 Mars Odyssey orbiter captured this incredible image of the giant shield volcano Arsia Mons, poking through the cloud tops at Martian dawn. Arsia and the other megavolcanoes on Mars are so tall they're often surrounded by water ice clouds in the early morning. Odyssey is normally staring straight down, so to capture this unique angle, it had to rotate 90 degrees while in orbit so that it could capture a side perspective view of the volcano.