New research suggests that dark matter, the universe's most puzzling and mysterious substance, may not exist. But removing dark matter from our cosmological models could hinge on the possibility that gravity behaves differently on very large scales, one scientist says.

Dark matter has been a thorn in the side of physicists because, despite outweighing ordinary matter by a ratio of 5 to 1, it remains effectively invisible. That's because it doesn't interact with light, or more technically, electromagnetic radiation. Because the particles that comprise the atoms that make up stars, planets, moons, living things, and everything we see around us, do interact with light, scientists have been searching for particles that could make up dark matter. However, this addition to particle physics, which has thus far eluded all attempts to uncover it, isn't needed if we are wrong about how gravity behaves on galactic scales. At least, that is what Naman Kumar of the Indian Institute of Technology suggests.

Averill is one of a group of researchers who are exploring a new potential avenue for treating PTSD: psychedelics. Psychedelic-assisted psychotherapy, using MDMA or psilocybin, may act on the brain systems disrupted in PTSD, rather than simply treating the symptoms.

The early findings have been positive: A recent clinical trial showed that 67% of patients who received MDMA-assisted therapy no longer met PTSD criteria after treatment, compared with 32% in the placebo group, and clinical trials investigating psilocybin's potential to treat the condition are showing promise.

Averill is currently leading a pioneering Texas state-funded clinical trial investigating psilocybin for veterans with PTSD and has seen how quickly the drugs can act.

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Researchers at Duke-NUS Medical School, together with international collaborators, have produced one of the most detailed single-cell maps of the developing human brain to date. This atlas catalogues almost every type of brain cell, documents their genetic signatures, and shows how they grow and communicate with one another. It also evaluates leading laboratory techniques used to generate high-quality neurons, representing a key advance toward new treatments for Parkinson’s disease and other neurological conditions.

Why Parkinson’s disease is a central focus
Parkinson’s disease is the second most common neurodegenerative disorder in Singapore and affects roughly three in every 1,000 people aged 50 and above. The disease destroys midbrain dopaminergic neurons—the cells responsible for releasing dopamine, a chemical essential for movement control and learning. Replacing or restoring these damaged cells could eventually help reduce symptoms such as tremors and loss of mobility.

Final Readiness Review: ✅

A crew of four, including esa's Soph astro, is getting ready for launch from NASA Kennedy in Florida, NET 11 February.

Get the latest on quarantine and what to expect on launch day!
🔗 esa.int/Science_Explor…

Oxygen is everywhere on Earth today. But that hasn’t always been the case. Scientists think oxygen only became a lasting part of the atmosphere about 2.3 billion years ago during the Great Oxidation Event (GOE), a turning point that ultimately shaped the rise of oxygen-using life.

Now, new research from MIT points to an even earlier chapter in this story. The team suggests that some ancient organisms may have learned to use oxygen hundreds of millions of years before the GOE. If correct, the evidence could rank among the earliest signs of aerobic respiration ever identified.

A juvenile sea urchin moving across its habitat, filmed at 10x magnification by zoologist Dr. Alvaro Migotto. See the rest of the winners of Nikon’s Small World in Motion competition in 2025: on.natgeo.com/4qzYUul

Alzheimer’s disease (AD) is the most common cause of dementia and affects close to 40 million people worldwide. As the condition progresses, individuals gradually lose memory, cognitive abilities, and independence. Despite decades of intensive research, there are still no treatments capable of stopping or reversing the underlying disease process.

One of the key drivers of brain dysfunction in AD is the protein tau. Under normal conditions, tau helps maintain the internal structure of neurons, supporting the transport systems that allow nerve cells to function properly. In Alzheimer’s disease, however, tau becomes abnormally modified and begins to clump together. These aggregates interfere with normal cellular transport, damage neurons, and ultimately contribute to memory impairment.

Now, an international team of scientists has identified a previously unrecognized way to protect the brain from this degeneration. Their research shows that increasing levels of the naturally occurring molecule NAD⁺ can counteract neurological damage linked to Alzheimer’s disease. The study was published in the journal Science Advances.

The collaboration was led by Associate Professor Evandro Fei Fang at the University of Oslo and Akershus University Hospital in Norway, together with Professor Oscar Junhong Luo from Jinan University in China and Associate Professor Joana M. Silva from the University of Minho in Portugal.

How NAD⁺ supports brain health
NAD⁺ (Nicotinamide adenine dinucleotide, oxidized form) is an essential molecule involved in cellular energy production and the ability of neurons to cope with stress. Levels of NAD⁺ naturally decline with age and drop even further in many neurodegenerative disorders.

“Previous research has suggested that boosting NAD⁺ using precursor compounds such as nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN) can produce beneficial effects in animal models of AD and in early-stage clinical studies. However, the biological processes responsible for these effects have remained poorly understood,” explains first author Alice Ruixue Ai.

The new study reveals that NAD⁺ works through a previously unidentified RNA-splicing pathway. This pathway is regulated by a protein called EVA1C, which plays an essential role in the process of RNA splicing. RNA splicing allows a single gene to produce multiple isoforms of a protein, and one isoform may show distinctive effects on the other isoforms. Its dysregulation is one of the most recently acknowledged risk factors for AD.

The James Webb Space Telescope (JWST) was designed to look back in time and study galaxies that existed shortly after the Big Bang. In so doing, scientists hoped to gain a better understanding of how the universe has evolved from the earliest cosmological epoch to the present. When Webb first trained its advanced optics and instruments on the early universe, it discovered a new class of astrophysical objects: bright red sources that were dubbed "Little Red Dots" (LRDs). Initially, astronomers hypothesized that they could be massive star-forming regions, but this was inconsistent with established cosmological models.

In essence, those models predicted that massive galaxies could not have formed less than a billion years after the Big Bang. This led to the theory that they might be quasars, the bright central regions of galaxies powered by supermassive black holes (SMBHs). This also challenged established models, as it was theorized that SMBHs wouldn't have had enough time to form either. In a recent paper posted to the arXiv preprint server, a team of astronomers led by Harvard University demonstrated that the mystery of LRDs could be explained by identifying them with accreting Direct Collapse Black Holes (DCBHs).

Their research is based on radiation-hydrodynamic (RHD) simulations developed to model the emission properties of DCBHs, a class of black holes that form directly from clouds of cold gas. This differs from conventional models that predict how black holes form from the collapse of massive stars. These massive stars, a theoretical class known as Population III, were the first stars in the universe, forming from hydrogen and helium with little to no traces of heavier elements (like metals).

Scientists at the University of New Hampshire are using artificial intelligence to dramatically speed up the search for new magnetic materials. Their approach has produced a searchable database containing 67,573 magnetic materials, including 25 previously unknown compounds that retain their magnetism at high temperatures, a key requirement for many real-world applications.

“By accelerating the discovery of sustainable magnetic materials, we can reduce dependence on rare earth elements, lower the cost of electric vehicles and renewable energy systems, and strengthen the U.S. manufacturing base,” said Suman Itani, lead author of the study and a doctoral student in physics.

A bottleneck in magnetic materials
The new resource, called the Northeast Materials Database, is designed to make it easier for researchers to explore the vast range of magnetic materials that underpin modern technology, from smartphones and medical devices to power generators and electric vehicles.

Today’s most powerful permanent magnets depend heavily on rare earth elements that are costly, largely imported, and increasingly difficult to secure. Despite the fact that scientists know many magnetic compounds exist, none have yet replaced rare-earth-based magnets in widespread use, creating a major bottleneck in materials innovation.

Lava tubes are natural underground tunnels formed by volcanic activity.

They typically originate in basaltic lava flows, where low-viscosity lava is either entrenched and crusted over or inflated in-between preexisting lava layers

Beside Earth, evidence of lava tubes has been identified on other celestial bodies such as Mars and the Moon.

For example, recent research provides compelling evidence of a subsurface cave conduit beneath the Mare Tranquillitatis Pit on the Moon.

The existence of lava tubes on Venus has been largely hypothesized but never confirmed.

“Our knowledge of Venus is still limited, and until now we have never had the opportunity to directly observe processes occurring beneath the surface of Earth’s twin planet,” said University of Trento’s Professor Lorenzo Bruzzone.

“The identification of a volcanic cavity is therefore of particular importance, as it allows us to validate theories that for many years have only hypothesized their existence.”

“This discovery contributes to a deeper understanding of the processes that have shaped Venus’ evolution and opens new perspectives for the study of the planet.”

A possible alternative to active debris removal (ADR) by laser is ablative propulsion by a remotely transmitted electron beam (e-beam). The e-beam ablation has been widely used in industries, and it might provide higher overall energy efficiency of an ADR system and a higher momentum-coupling coefficient than laser ablation. However, transmitting an e-beam efficiently through the ionosphere plasma over a long distance (10 m–100 km) and focusing it to enhance its intensity above the ablation threshold of debris materials are new technical challenges that require novel methods of external actions to support the beam transmission.

Therefore, Osaka Metropolitan University researchers conducted a preliminary study of the relevant challenges, divergence, and instabilities of an e-beam in an ionospheric atmosphere, and identified them quantitatively through numerical simulations. Particle-in-cell simulations were performed systematically to clarify the divergence and the instability of an e-beam in an ionospheric plasma.

How did the complexity of many organisms living today evolve from the simpler body plans of their ancestors? This is a central question in biology. Take our hands, for example: Every time we type a message on our mobile phone, we are using an evolutionary "masterpiece" that evolved over millions of years. Notably, we typically grasp and manipulate objects with the palm of our hand—its ventral side. The back of our hand, or dorsal side, plays almost no role. This differentiation of our limbs, with a ventral side adapted for contact and a dorsal side protected by nails or toenails, is essential for life on land.

But how does nature distinguish between the top and the bottom sides of a limb, and which adjustments to the genetic machinery were necessary during evolution to make this possible? An international research team led by Konstanz-based biologist Joost Woltering has the answers. In their recent article published in Molecular Biology and Evolution, they describe how ancient genes from the midline fin of fish had to be "redeployed" to establish the dorsal-ventral axis in our limbs.

An anatomical puzzle
The evolutionary journey from ancient fins to the human hand began roughly 500 million years ago. Around that time, the genetic program for fins typically found on a fish's back—the midline fins—was copied and activated on the flank of one of our aquatic ancestors. This gave rise to the first fish with paired fins. About 350 million years ago, these paired fins evolved into the paired limbs of vertebrates, including our arms and legs.

There's no denying that something massive lurks at the heart of the Milky Way galaxy, but a new study asks whether a supermassive black hole is the only possible explanation.

All measurements taken of the galactic center to date are consistent with a highly dense object around 4 million times as massive as the Sun. According to the new paper, though, if you squint just a little, all that evidence can also apply to a giant, compact blob of fermionic dark matter, without an event horizon.

We currently don't have the observational precision to tell the difference between these two models. However, a dark matter composition of the galactic nucleus would give astronomers a new tool for interpreting the dark matter structure of the entire galaxy.

"We are not just replacing the black hole with a dark object; we are proposing that the supermassive central object and the galaxy's dark matter halo are two manifestations of the same, continuous substance," explains astrophysicist Carlos Argüelles of the Institute of Astrophysics La Plata in Argentina.

Tour the International Space Station with NASA astronauts Nicole Mann and Kjell Lindgren as they celebrate 25 years of continuous human presence in orbit. Explore what it’s like to live in microgravity, float through the station, and conduct science that benefits people on Earth and enables NASA’s missions to the Moon and Mars.
Celebrate with us at nasa.gov/international-sp....

Researchers have pinpointed the tiny chemical attractions that help spider silk pull off its famous balancing act: extreme strength without losing flexibility. By explaining what holds the material together at the molecular scale, the work could make it easier to design bio-inspired fibers for aircraft parts, protective clothing, and medical uses. The same kinds of self-organizing behaviors may also offer clues about neurological diseases, including Alzheimer’s.

Instead of treating spider silk as a mystery material to copy outright, the team focused on the underlying “rules” that nature uses, principles that could be applied to build a new generation of high-performance, more sustainable fibers.

Revealing the Molecular Design of Spider Silk
Spider silk is made from proteins, long chains built from amino acids. The study reports that, inside these proteins, certain amino acids interact in a way that behaves like molecular “stickers.” Those repeating, reversible connections help the proteins gather, organize, and ultimately lock into a structure that can handle both stretching and heavy loads.

Hubble has captured the light show around a dying star

This is the Egg Nebula 🥚 the first, youngest, and closest pre-planetary nebula ever discovered. This pre-planetary stage lasts only a few thousand years, making the Egg Nebula a valuable target for astronomers studying stellar evolution. Twin beams from the star light up polar lobes that pierce a series of concentric arcs. Their shapes and motions suggest the presence of companion stars hidden within the thick dust.

The patterns captured by Hubble are too orderly to result from a violent explosion like a supernova. Instead, they likely come from a mysterious sequence of sputtering events in the core of the dying star!

Read more: esahubble.org/news/heic2604/

Researchers at Northwestern University have created the most sophisticated lab grown model of human spinal cord injury so far.

In the new study, scientists worked with human spinal cord organoids grown from stem cells. These miniature, simplified versions of the spinal cord allowed the team to recreate different forms of spinal cord trauma and evaluate a promising regenerative treatment.

For the first time, the organoids closely reproduced the major features of spinal cord injury seen in people. That included widespread cell death, inflammation, and glial scarring. Glial scars are thick clusters of scar tissue that form after injury and create both physical and chemical barriers that block nerve repair.

When the damaged organoids were treated with “dancing molecules” — a therapy that previously reversed paralysis and repaired tissue in animal studies — the results were striking. The injured tissue produced significant neurite outgrowth, meaning the long extensions of neurons began growing again. Scar like tissue was greatly reduced. The findings strengthen hopes that the treatment, which recently received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA), could improve recovery for people living with spinal cord injuries.

A world can look promising from afar and still be missing the chemical ingredients that biology depends on. Two of the most critical are phosphorus and nitrogen, and they act like gatekeepers for life. Phosphorus is built into DNA and RNA, the molecules that store and pass along genetic information, and it also helps cells manage energy. Nitrogen is a core ingredient in proteins, which living things rely on to build cells and keep them working.

What makes these elements especially interesting is that a planet can lose access to them long before its surface becomes stable. A study led by Craig Walton, a postdoctoral researcher at the Centre for Origin and Prevalence of Life at ETH Zurich, together with ETH professor Maria Schönbächler, found that phosphorus and nitrogen must be available at the moment a planet forms its core.

“During the formation of a planet’s core, there needs to be exactly the right amount of oxygen present so that phosphorus and nitrogen can remain on the surface of the planet,” explains Walton, lead author of the study.

Earth appears to have hit that chemical balance around 4.6 billion years ago, which may help explain why it ended up with the raw materials life needs. The result could reshape how scientists judge the chances for life elsewhere in the universe.

Core formation as a form of cosmic roulette
Young rocky planets begin as roiling oceans of molten rock. As gravity pulls materials into layers, dense metals such as iron sink inward to form the core, while lighter material remains above to become the mantle and, later, the crust. That physical separation is only half the story. At the same time, chemistry is deciding which elements prefer metal and which prefer rock, and oxygen is one of the biggest drivers of that choice.

Researchers at Kyoto University are advancing a new idea about how space weather might intersect with earthquake physics. Their model asks whether changes in the ionosphere could, in rare situations, apply additional electrical forces to already fragile parts of the Earth’s crust and help nudge a large quake toward initiation.

The work is not an earthquake forecasting method. Instead, it lays out a physical pathway that starts with solar flares and other intense solar activity, which can rapidly reshape the distribution of charged particles high above Earth. Those ionospheric charge shifts are measurable because they alter how satellite navigation signals travel through the upper atmosphere, a key reason scientists track total electron content in the first place.

Inside the crust, the model focuses on fractured rock zones that can trap water at extreme temperatures and pressures, potentially reaching a supercritical state. Under these conditions, the researchers treat the damaged region as electrically active, acting like a capacitor that is linked through capacitive coupling to both the ground surface and the lower ionosphere. In effect, the crust and the ionosphere become parts of one large electrostatic system rather than isolated layers.

Electrostatic Forces From Solar Activity
During strong solar events, electron density in the ionosphere can rise enough to form a more negative layer at lower altitudes. The model proposes that this atmospheric charge does not stay confined overhead. Because the system is capacitively connected, the changing ionospheric charge can translate into intensified electric fields within tiny voids in fractured crustal rock, on the scale of nanometers.

Why does that matter for earthquakes? Pressure inside small cavities can influence how cracks grow and merge, especially when a fault zone is already close to failure. In the Kyoto team’s calculations, the resulting electrostatic pressure can reach levels comparable to other subtle forces known to affect fault stability, including tidal and gravitational stresses.