Universe Today

The surface of the Earth is finite. We can measure it. If it was expanding, then its size would grow with time. And once again, good ol’ Earth helps us understand what the universe might be doing beyond our observable horizon.

Material science plays a critical role in space exploration. So many of the challenges facing both crewed and non-crewed missions come down to factors like weight, thermal and radiation tolerance, and overall material stability. The results of a new study from Young-Kyeong Kim of the Korea Institute of Science and Technology and their colleagues should therefore be exciting for those material scientists who focus on radiation protection. After decades of trying, the authors were able to create a fully complete “sheet” of Boron Nitride Nanotubes (BNNTs).

Scientists have achieved a breakthrough that seemed impossible just months ago, they have simulated our entire Milky Way galaxy down to each of its 100 billion individual stars. By combining artificial intelligence with supercomputer power, researchers created a model that captures everything from galactic arms to the explosive deaths of individual stars, completing in days what would have taken conventional simulations 36 years. This fusion of AI and physics represents a significant shift in how we model complex systems, with implications reaching far beyond astronomy.

Scientists from New York University Abu Dhabi (NYUAD) have uncovered new evidence that water once flowed beneath the surface of Mars, revealing that the planet may have remained habitable for life much longer than previously thought.

An expanding universe complicates this picture just a little bit, because the universe absolutely refuses to be straightforward.

I honestly don’t have a decent analogy for you to explain how the universe is expanding without a center and without an edge. It just does, whether we can wrap our minds around it or not. But I CAN give you a way to think about it.

Satellite megaconstellations are quickly becoming the backbone of a number of industries. Cellular communication, GPS, weather monitoring and more are now, at least in part, reliant on the networks of thousands of satellites cruising by in low Earth orbit. But, as these constellations grow into the tens of thousands of individual members, the strain they are putting on the communications and controls systems of their ground stations is becoming untenable. A new paper from Yuhe Mao of the Nanjing University of Aeronautics and Astronautics and their co-authors hopes to alleviate some of that pressure by offloading much of the control scheme and network decision-making logic to satellites themselves.

Let’s start out with something that we can say for certain: we live in an expanding universe.

Travelling up from Mars’s equator towards its north pole, we find Coloe Fossae: a set of intriguing scratches within a region marked by deep valleys, speckled craters, and signs of an ancient ice age.

The Moon gains new craters all the time, but catching one forming is surprisingly rare. Between 2009 and 2012, something struck our celestial companion just north of Römer crater, creating a bright 22 metre scar with distinctive rays of ejected material spreading outward. While the Moon's most dramatic bombardment ended billions of years ago, this fresh impact reminds us that our nearest neighbour continues to be peppered by space rocks, offering scientists a rare opportunity to study crater formation in real time and refine our understanding of impact rates across the Solar System.

When an interstellar comet tears through our Solar System at 250,000 kilometres per hour, pinning down its exact trajectory becomes a race against time. ESA astronomers achieved something unprecedented in October 2025, using observations from the ExoMars Trace Gas Orbiter to improve predictions of comet 3I/ATLAS's path by a factor of ten. By triangulating data from Mars with Earth based observations, scientists demonstrated a powerful technique for tracking fast moving objects that could prove invaluable for planetary defence, even though this particular visitor poses no threat to our planet.

Exoplanets need not acquire their water from external sources like asteroids and comets. New experiments show that at least one common type of exoplanet can generate its own water. Interactions between hydrogen and silicates on sub-Neptunes can create water that could make some of the habitable.

A gaseous, dusty structure in the Cygnus X star formation region is reminiscent of a glowing diamond ring. There are others that are similar, but they're spherical and this one is flat. A team of researchers have figured out why.

Over the course of billions of years, the universe has steadily been evolving. Thanks to the expansion of the universe, we are able to “see” back in time to watch that evolution, almost from the beginning. But every once in a while we see something that doesn’t fit into our current understanding of how the universe should operate. That’s the case for a galaxy described in a new paper by PhD student Sijia Cai of Tsinghua University’s Department of Astronomy and their colleagues. They found a galaxy formed around 11 billion years ago that appears to be “metal-free”, indicating that it might contain a set of elusive first generation (Pop III) stars.

All of the proposals floating around out there for invoking dynamical dark energy are a little on the weak side. In many cases, they raise more questions than answers.

Researchers using the NASA/ESA/CSA James Webb Space Telescope have confirmed an actively growing supermassive black hole within a galaxy just 570 million years after the Big Bang. Part of a class of small, very distant galaxies that have mystified astronomers, CANUCS-LRD-z8.6 represents a vital piece of this puzzle that challenges existing theories about the formation of galaxies and black holes in the early Universe. The discovery connects early black holes with the luminous quasars we observe today.

Observations of a merging black hole further supports the Area Theorem of black hole thermodynamics, which states that the event horizon of a black hole produced by two merging black holes must have a surface area no less than the areas of the original two.

Tracking down black holes at the center of dwarf galaxies has proven difficult. In part that is because they have a tendency to “wander” and are not located at the galaxy’s center. There are plenty of galaxies that might contain such a black hole, but so far we’ve had insufficient data to confirm their existence. A new paper from Megan Sturm of Montana State University and her colleagues analyzed additional data from Chandra and Hubble on a set of 12 potential Active Galactic Nuclei (AGN) galaxy candidates. They were only able to confirm three, which highlights the difficulty in isolating these massive wanderers.

To be fair, all scientific models are in some sense wrong

Galaxies grow massive through mergers with other galaxies. Massive galaxies like the Milky Way and Andromeda not only merge with other large galaxies, they also absorb their much smaller satellite dwarf galaxies. But these smaller galaxies can become quenched long before they're absorbed, and new research examines this process at Andromeda (M31).