Need some good news on a Friday after a long week? The Earth may not be engulfed by the expanding fireball of the dying sun, which has long been assumed to be our home planet's ultimate fate, according to scientists.

Don't worry: This is not expected to happen for another 5 billion years, long after all life on Earth has been wiped out.

When the sun burns through all of the hydrogen in its core, it will go through two immense expansion phases: first becoming a red giant, then, when its helium is spent, an "AGB" star. This fiery death will bring about some significant changes back here on Earth. As the sun grows, increasing gravitational forces will pull the Earth toward it.

For the Earth and the moon, this force creates the push and pull of the tides in our oceans. The energy from these tides, which dissipates at the bottom of the ocean, slows Earth's rotation and gradually pushes the moon away from us.

As the sun expands and its blistering surface approaches Earth, intense tidal waves will stir within the star. When they dissipate, they will pull Earth into its doomed embrace. However, the growing sun will also lose a lot of its mass due to stellar wind, which pushes our planet farther away.

"Earth's fate depends on a delicate balance between these two effects," explained Mats Esseldeurs, the lead author of a study published in the journal Astronomy & Astrophysics on Friday.

"If tidal interactions predominate, Earth is engulfed by the sun. If the sun's mass loss predominates, Earth escapes into an orbit larger than the radius of its star," the astrophysicist at Belgium's University of Leuven said in a statement.

Until now, scientists had favored the first hypothesis.

Catching some sun
However, their calculations relied on relatively simple descriptions of tidal dissipation within giant stars. Advances made in modeling these tides over the last 15 years have enabled the study's authors to show that "the dissipation is lower than previously expected," Stephane Mathis, an astrophysicist at the CEA Paris-Saclay center in France, told AFP.

To estimate how much mass the sun could lose, the team focused in particular on a nearby star called L2 Puppis that is like the sun's "old cousin," the study's co-author said. "A better understanding of tidal physics and the most advanced constraints we have on mass loss allow us to say that—in the current state of knowledge—Earth could move away from the sun, contrary to what was predicted before," Mathis said.

According to the new modeling, Mars also escapes a death spiral into the sun. But the two planets closest to the sun, Mercury and Venus, are not so lucky. They will be inexorably swallowed by the expanding fireball. After all this, the sun will eventually become an extremely dense star called a white dwarf. No longer capable of fusion reactions, it will slowly become dimmer and cooler over time.

Keeping global warming below 1.5°C over the long term will require more than major cuts in greenhouse gas emissions. According to climate scenarios outlined in the latest Assessment Report from the Intergovernmental Panel on Climate Change (IPCC), the world will also need technologies capable of removing and storing hundreds of billions of tons of carbon dioxide (CO2) already in the atmosphere.

One approach receiving increasing attention is “direct air capture” (DAC), a technology that removes CO2 directly from the air. Researchers and startups have spent years trying to improve DAC systems. One of the earliest commercial companies in the field is Climeworks, an ETH Zurich spin-off founded in 2009. Despite progress, direct air capture remains costly and requires significant amounts of energy.

Food Waste Turned Into Carbon Capture Material
Researchers at ETH Zurich have now developed a new DAC approach that could make the process more efficient and sustainable. In a study published in the journal PNAS, a team led by materials scientist Raffaele Mezzenga used waste products from dairy and tofu manufacturing to capture CO2.

Large amounts of protein-rich liquid are generated during the production of dairy products and tofu. Only a small portion is reused in food manufacturing, while much of the rest is discarded. The researchers extracted proteins from this waste stream and assembled them into long, thread-like structures called amyloid fibrils. These fibrils were then combined with potassium hydroxide and formed into porous beads measuring about half a centimeter to one centimeter in diameter.

“The resulting material is like a sponge that can absorb large quantities of CO2 via the potassium hydroxide,” Mezzenga explains.

When exposed to air, the potassium hydroxide inside the beads reacts with CO2 and converts it into hydrogen carbonate, a salt of carbonic acid. This reaction removes carbon dioxide from the atmosphere.

“In our tests with ambient air, we were able to extract 97 milligrams of CO2 with one gram of material,” explains Zhou Dong, a postdoctoral researcher in Mezzenga’s group and lead author of the study.

According to Dong, this performance is exceptionally strong, exceeding the capacity of conventional DAC technologies by 10 to 50 percent. Based on the team’s calculations, one kilogram of the protein beads could theoretically capture and isolate 100 grams of CO2 during a single operating cycle.

Lower Energy Carbon Removal
Most existing direct air capture systems rely on heat and negative pressure to release the captured carbon dioxide from the absorbent material. The recovered CO2 can then be stored or converted into other products, allowing it to be removed from the atmosphere over the long term. However, generating the necessary heat requires substantial energy, making DAC economically and environmentally viable mainly in places with abundant renewable energy.

The ETH Zurich team developed a different solution. To release the captured carbon dioxide, the protein beads are sprayed alternately with a mild acid and a mild base for approximately 10 minutes at room temperature. This process breaks the chemical bonds holding the CO2, allowing it to be collected.

The acid, base, and protein beads can all be reused afterward.

If we’re to reach another star, chemical propulsion will not get us there in any reasonable time frame. We’re going to need a different propulsion technology, and one of the most promising seems to be a solar sail. These giant reflective surfaces form the basis of many interstellar missions. Combined with giant lasers pushing them, they can be accelerated to speeds unreachable by any other current technologies. However, according to a new paper available on arXiv from Chao Shen and Jiaze Li of the Harbin Institute of Technology, once those missions start reaching a significant percentage of the speed of light they’re going to run into a drag force from the light itself.

The paper breaks down the three forces photons hitting a solar sail impart to it. In order of decreasing efficiency they are incident light (that raw momentum of the photons hitting the sail), specular reflection (momentum imparted when photons bounce perfectly off the sail), and diffuse scattering (momentum from photons that are absorbed by the sail then reemitted in random directions).

When the light sail starts to reach relativistic speeds is where the problems start to come in. As it speeds away from its light source it starts to experience a severe Doppler effect. As the frequency of the light drops, the thrust generated by the three components of light rapidly decreases, making it harder and harder to keep accelerating the faster you go.

Many interstellar missions have come and gone - including Breakthrough Starshot

It gets even worse when the light sail hits 75% of the speed of light. At that point, a phenomenon called relativistic light aberration takes over. From the perspective of a stationary observer on Earth, the diffusely scattered light is directed forward towards the sail’s direction of motion. Since every action must have an equal and opposite reaction, that means the diffuse scattering (admittedly the weakest of the three forces) becomes an active drag on the system past 75% of the speed of light.

Admittedly, the net force of the pushing laser remains positive at that point, but the efficiency drop-off is significant. It is worth noting that the paper focuses exclusively on radiative dynamics and does not account for non-radiative factors, such as drag from interstellar gas or dust, nor does it address thermal limitations of sail materials, such as potential melting under high-power lasers. The paper treats the lightsail material as an idealized mirror. In practice, aerospace engineers are exploring advanced metamaterials and photonic crystals tuned to specific laser wavelengths. These materials could potentially leverage the aberration effects discussed in the paper to actively self-correct and stabilize the lightsail’s flight path, ensuring it remains centered in the beam.

The two-part Viking 1 spacecraft reached Mars orbit 50 years ago. A few days later, the images it returned of the proposed Viking 1 landing site were met with both elation and shock.

Mars as viewed by Viking 1's cameras did not look like the planet Mariner 9 saw. The Viking 1 Lander's proposed landing site, chosen after years of debate, lay on the floor of what looked like a deeply incised river bed. America's first Mars landing—scheduled for July 4, 1976, America's Bicentennial—would have to be delayed so a less risky landing spot could be found.

📷 This mosaic of Mars is a compilation of images captured by the Viking Orbiter 1. The center of the scene shows the entire Valles Marineris canyon system.

Hydrogen is the simplest element in the universe and the first entry on the periodic table. Each hydrogen atom contains just one proton in its nucleus and one electron orbiting around it. Because of this simplicity, hydrogen has long served as an important testing ground for studying the fundamental forces and particles that shape the universe.

Yet one seemingly basic property of hydrogen has puzzled physicists for more than a decade: the exact size of its proton. Known as the proton radius puzzle, the debate centered on conflicting measurements of the proton’s radius.

Researchers at Colorado State University (CSU) now report an exceptionally precise measurement that appears to settle the issue. The results, highlighted in Physical Review Letters, strengthen confidence in the Standard Model of particle physics while providing a foundation for future research.

Precision Measurement Confirms Standard Model
Previous experiments produced conflicting answers. Measurements that used electrons suggested one proton radius, while studies using heavier particles indicated a slightly smaller value. The disagreement was comparable to measuring the same house with two reliable tools and getting different dimensions.

The inconsistency raised important questions. It suggested either that earlier experiments contained hidden sources of error or that physicists might need to revise some of the fundamental principles used to describe the universe.

The new CSU measurement places the proton’s radius at about 0.84 femtometers, compared with the previously accepted value of 0.876 femtometers. Although the difference is extremely small, it is significant for precision physics. An independent team at the Max Planck Institute reached a similar conclusion using a different technique, providing additional confidence that the long-running discrepancy has finally been resolved.

While the adjustment to the proton’s size is tiny, its implications are substantial for our understanding of matter and the laws governing the universe...

Why do we decide to approach other people? According to new research, the answer may start unfolding in the brain several seconds before any movement takes place.

A team of scientists from the Hebrew University of Jerusalem has identified a distinctive pattern of brain activity that appears before social interaction begins. Their findings suggest that the brain is already preparing for a social encounter before an individual takes action, and that the strength of this neural activity may reflect how socially motivated someone is.

Tracking Social Decisions in Real Time
To investigate how social decisions are formed, the researchers used zebrafish, a popular model organism that allows scientists to observe activity across the brain at the level of individual cells.

The team created a new experimental system in which one fish watched and responded to another fish that was swimming nearby. While this happened, researchers recorded activity throughout the observing fish’s brain in real time.

This approach allowed them to follow the neural processes involved in social behavior as they unfolded, revealing how the brain transforms social information into action.

A Brain-Wide Signal Before Social Behavior
The researchers discovered that the brain begins shifting into a different state several seconds before a fish moves toward another fish.

Rather than relying on a single region dedicated to social behavior, the process involved coordinated changes across multiple parts of the brain.

Globally, humanity now produces a staggering 450 million tonnes of plastic every year. From food and drink containers to cosmetics packaging, sewage pipes, window frames and polyester clothing, we use plastics in almost every area of life. And nearly one-quarter of them end up in the environment, where they very slowly degrade into microscopic pieces.

These microplastics—particles between 1 micrometer and 5 millimeters wide—have been found in the deepest parts of the oceans, at the top of the tallest mountains, at the sparsely populated poles and even inside the human body.

It is very difficult for living organisms, including humans, to avoid ingesting microplastics. If these microplastics cross the lining of the digestive tract to enter the bloodstream or other tissues, they will persist in the body. Until now, it has been difficult for researchers to accurately assess whether this is happening.

Our research team has developed a new technique to identify the location of microplastics within an organism without dissecting it. We tested it on earthworms and discovered that microplastics ranging in size from 5 to 53 micrometers do not readily cross the lining of the gut to enter other tissues in the worms...

For decades, inflammatory bowel disease (IBD) has been treated as a single disorder, even though patients often experience dramatically different symptoms, disease courses, and responses to therapy. A new study suggests there may be a good reason for that: what doctors call IBD could actually be a collection of distinct diseases driven by different biological mechanisms.

Researchers from the University of Oxford’s Nuffield Department of Medicine, Newcastle University’s Translational and Clinical Research Institute, and the Department of Immunology at Cambridge University Hospitals NHS Foundation Trust have identified a key driver of disease in a subset of patients. Their findings, published in the New England Journal of Medicine, reveal an immune malfunction that not only triggers uncontrolled inflammation but also helps explain one of the strongest genetic risk factors linked to IBD.

The team analyzed more than 4,900 people with Crohn’s disease and ulcerative colitis, the two main forms of IBD. They discovered that some patients develop autoimmune responses against interleukin-10 (IL-10), a crucial molecule that normally acts as one of the body’s primary brakes on inflammation. They also found that this immune attack is closely tied to a genetic variant long associated with severe IBD.

Under normal circumstances, IL-10 helps prevent the immune system from overreacting and damaging healthy tissue. But when antibodies block IL-10, this protective mechanism is disabled, allowing inflammation to persist unchecked and potentially fueling disease.

The world relies on a modest number of countries to keep watch over the ocean. That arrangement is starting to fail. Europe and Asia must now decide whether to let the system unravel, or to take it up together.

Right now, in every ocean basin on Earth, a global network of instruments measures the state of the sea.

Research ships steam along oceanographic transects from surface to seafloor. Anchored buoys watch the tropical oceans for the first signs of El Niño or tropical cyclones and take the pulse of the thermohaline circulation. Some 4,000 autonomous floats sink every 10 days to 2,000 meters before rising to transmit temperature and salinity to ground stations via satellite. Underwater gliders patrol continental margins, and drifting buoys ride the surface in the most remote waters. Hundreds of elephant seals carry miniaturized sensors beneath the polar sea ice...

Together, this network produces invaluable information that allows societies to anticipate and respond to changing ocean and weather conditions, and protect the ocean in return.

It is also far more fragile than most people, and most governments, realize. A new study published in Nature Climate Change has measured for the first time just how fragile the ocean watch network is.

The result is alarming. If observations from a single major contributor, the United States, were withdrawn from the Global Ocean Observing System (GOOS), the errors in our estimate of how fast the ocean is warming would jump by 163%. That is worse than randomly losing 80% of all global ocean data. The reason is geographical: U.S. instruments cover every ocean basin and plug critical gaps that no other nation currently fills.

This is not a theoretical concern. Proposed cuts to National Oceanic and Atmospheric Administration and the National Science Foundation in the United States now threaten exactly this contribution. And the situation is barely better on the other side of the Atlantic.

The pressures are not confined to one side of the Atlantic, nor to the West. In China, scientists and policymakers are working to build a more resilient national contribution to ocean observation, but without the resources the moment requires. The marine monitoring system the world relies on is under strain almost everywhere.

19 years ago today: Space Shuttle Atlantis' main landing gear touches down at Edwards Air Force Base in California concluding a two-week assembly mission to the International Space Station.

Sunita Williams, a flight engineer on the Expedition 15 crew, returned to Earth on STS-117 completing 194 days in space, the longest single spaceflight ever by a female astronaut or cosmonaut to that date. This record is now held by Christina H Koch for her 2019–2020 spaceflight (328 days).