The Lambda Cold Dark Matter (Lambda CDM) model is the current cosmological model and explains much of what we see in the cosmos. One of Lambda CDM's core features is the prediction that structure grows hierarchically from the bottom up. It begins with dark matter density fluctuations, then dwarf galaxies form, then those dwarfs merge to form more massive galaxies, which merge into still larger galaxies. Eventually, there are galaxy clusters.
Space News & Blog Articles
For decades, Mercury has carried the reputation of being a dead, dry planet whose geological story ended long ago. Its cratered surface, baked by the Sun and seemingly frozen in time, appeared to tell a tale of ancient violence followed by billions of years of silence. That story just got considerably more interesting.
BepiColombo is slowly uncovering more and more fun facts about Mercury as it continues its preliminary mission. One of the more interesting things found so far is a magnetic “chorus” that appears similar to a phenomenon found in Earth’s much larger magnetic field. A new paper in Nature Communications from the researchers responsible for the probe’s Mio instrument that is studying Mercury’s magnetic field describes what could be thought of as a form of magnetic birdsong.
AI faces daily criticism from people worried about its ill-effects. But the type of AI that draws this ire are Large Language Models (LLMs). There are other types of AI with specialized functions that don't make it onto the front pages. Combing through vast troves of astronomical data is a perfect task for AI that is unlikely to be replicated by human minds.
Dark matter doesn't emit light, it doesn't absorb light and it doesn't even block it, passing through ordinary matter like a ghost through walls (I’m very proud of that sentence.) Yet this invisible substance makes up roughly 85% of all matter in the universe, and its gravitational influence has shaped everything from galaxy clusters millions of light years across down to the rocky planet beneath our feet.
When Halley's Comet blazed across English skies in April 1066, an elderly Benedictine monk named Eilmer watched from Malmesbury Abbey with growing recognition. "You've come, have you?" he reportedly said, crouching in terror at the glowing apparition. "You've come, you source of tears to many mothers." But Eilmer's words carried weight beyond mere dread, he realised he had seen this exact comet before, during its previous appearance in 989 when he was just a young man.
Deep in the frozen heart of Antarctica, the South Pole Telescope has been watching one of the most extreme neighbourhoods in our Galaxy, and it's just caught something extraordinary happening there. Astronomers have detected powerful stellar flares erupting from stars near the supermassive black hole at the centre of the Milky Way. These aren't your average stellar flares, we're talking about energy releases so intense they make our Sun's most dramatic outbursts look like flickering candles.
When astronomers look out into the cosmos, they see supermassive black holes (SMBH) in two different states. In one state, they're dormant. They're actively accreting only a tiny amount of matter and emit only faint, weak radiation. In the other, they're more actively accreting matter and emitting extremely powerful radiation. These are normally called active galactic nuclei (AGN).
Astronomers have puzzled over Fast Radio Bursts (FRBs) since the Lorimer Burst (the first confirmed FRB) was detected in 2007. These rapid bursts of radio waves coming from distant galaxies last between milliseconds and a few seconds and release as much energy as the Sun produces in days. Whereas most FRBs are one-off events, astronomers have found some rare cases where FRBs were repeating in nature. For years, scientists have speculated as to what causes these events, with theories ranging from neutron stars and black holes to extraterrestrial communications.
How can microorganism communities known as biofilms, and have been hypothesized to be responsible for early life on Earth, be used for space exploration? This is what a recent study published in *npj Biofilms and Microbiomes* hopes to address as an international collaboration of researchers investigated the pros and cons of using biofilms in spaceflight. This study has the potential for scientists to better understand the role of biofilms in spaceflight while mitigating health risks of astronauts.
Lately we’ve been reporting about a series of studies on the Habitable Worlds Observatory (HWO), NASA’s flagship telescope mission for the 2040s. These studies have looked at the type of data they need to collect, and what the types of worlds they would expect to find would look like. Another one has been released in pre-print form on arXiv from the newly formed HWO Technology Maturation Project Office, which details the technology maturation needed for this powerful observatory and the “trade space” it will need to explore to be able to complete its stated mission.
In our galaxy, a supernova explodes about once or twice each century. But historical astronomical records show that the last Milky Way core-collapse supernova seen by humans was about 1,000 years ago. That means we've missed a few.
In recent years, astrophysicists have discovered supermassive black holes (SMBH) in the early Universe that are much larger than they should be. Black hole growth is restrained by the Eddington Mass Limit, a cap on the growth rate of black holes. But objects can exceed this limit in certain circumstances, and that's called super-Eddington accretion. san Super-Eddington accretion explain these early SMBH?
There’s a bright side to every situation. In 2032, the Moon itself might have a particularly bright side if it is blasted by a 60-meter-wide asteroid. The chances of such an event are still relatively small (only around 4%), but non-negligible. And scientists are starting to prepare both for the bad (massive risks to satellites and huge meteors raining down on a large portion of the planet) and the good (a once in a lifetime chance to study the geology, seismology, and chemical makeup of our nearest neighbor). A new paper from Yifan He of Tsinghua University and co-authors, released in pre-print form on arXiv, looks at the bright side of all of the potential interesting science we can do if a collision does, indeed, happen.
How long did it take to establish the water content within Jupiter’s Galilean moons, Io and Europa? This is what a recent study published in The Astrophysical Journal hopes to address as a team of scientists from the United States and France investigated the intricate processes responsible for the formation and evolution of Io and Europa. This study has the potential to help scientists better understand the formation and evolution of two of the most unique moons in the solar system, as Io and Europa are known as the most volcanically active body in the solar system and an ocean world estimated to contain twice the volume of Earth’s oceans, respectively.
Bacteria and the viruses that infect them have been locked in an evolutionary battle for billions of years. Bacteria evolve defences against viral infection and viruses develop new ways to breach those defences. This process shapes microbial ecosystems across Earth, from ocean depths to soil communities. But what happens when you take that battle to space?
Space debris encompasses thousands of defunct satellites, spent rocket stages, and fragments from collisions or explosions that orbit Earth at speeds exceeding 27,000 kilometres per hour. This growing population of human made junk poses collision risks to operational spacecraft and, when gravity eventually pulls larger pieces down through the atmosphere, can threaten people on the ground with falling fragments that sometimes survive reentry intact.
Stars change in brightness for all kinds of reasons, but all of them are interesting to astronomers at some level. So imagine their excitement when a star known as J0705+0612 (or, perhaps more politically incorrectly, ASASSN-24fw) dropped to around 2.5% of its original brightness for 8.5 months. Two new papers - one from Nadia Zakamska and her team at the Gemini Telescope South and one from Raquel Forés-Toribio at Ohio State and her co-authors - examine this star and have come to the same conclusion - it’s likely being caused by a circumsecondary disk.
Scientists have known that Mars has water for some years, documenting ice beneath the surface, moisture locked in soil, and vapour drifting through the thin atmosphere. The challenge facing future human missions isn't finding water on the Red Planet, it’s figuring out how to actually extract and use it.
Comets inhabit the cold reaches of the Solar System: the Kuiper Belt and the Oort Cloud. Occasionally, one passes through the inner Solar System, but mostly they keep to themselves out there. These dirty snowballs are agglomerations of rock and dust, and frozen volatiles like water, carbon dioxide, methane, and ammonia. They also contain organic materials.
Supermassive Black Holes (SMBHs), which reside at the center of many galaxies, play a central role in the evolution of these cosmic structures. This includes how they power Active Galactic Nuclei (AGNs), in which the core region emits enough radiation and light to temporarily outshine all the stars in the disk. They also "seesaw" between relativistic jets emanating from their poles to outflows of jets that suppress star formation in the surrounding core. Despite this broad understanding, scientists have been waiting for the day when they can peer directly into the heart of a galaxy's core and see what's going on there.

