Using observations from the James Webb Space Telescope (JWST), astronomers discovered this dramatic daily weather cycle on the distant world, located nearly 700 light years from Earth in the constellation Microscopium. The findings mark one of the first times scientists have directly observed cloud cycling on a Hot Jupiter exoplanet.

The discovery also gave researchers a much clearer view of the planet’s atmosphere, helping them better understand what the world is made of and how its weather behaves. The study was published in the journal Science.

“I’ve been looking at exoplanets for 20 years, and general cloudiness has been a thorn in our side. We’ve known for quite a while that clouds are pervasive on Hot Jupiter planets, which is annoying because it’s like trying to look at the planet through a foggy window,” said co-author and program PI, David Sing, a Bloomberg Distinguished Professor of Earth and Planetary Sciences at Johns Hopkins. “Not only have we been able to clear the view, but we can finally pin down what the clouds are made out of and how they’re condensing and evaporating as they move around the planet.”

Extreme Weather on WASP-94A b

To study WASP-94A b, scientists observed the planet as it crossed in front of its host star. During this transit, JWST was able to separately examine the leading and trailing edges of the planet as it moved across the star’s light.

The leading edge represents the planet’s morning side, where atmospheric winds carry air from the cooler night side toward the intensely hot day side. The trailing edge acts as the evening side, where air moves back toward darkness.

The observations revealed a striking difference between morning and evening conditions. The morning side was packed with clouds made of magnesium silicate, a mineral commonly found in rocks on Earth. The evening side, however, appeared almost cloud free.

Researchers believe there are two possible explanations for the disappearing clouds. One idea is that powerful winds drag the clouds deep into the planet’s atmosphere on the scorching day side, effectively hiding them from view. Another possibility is that the clouds evaporate as they move into temperatures exceeding 1,000 degrees, similar to morning fog burning away on Earth but under far more extreme conditions.

“It was a huge surprise. People have expected some differences, like its cooler in the morning than the evening — that’s something natural that we experience here on Earth,” Sing said. “But what we saw was a real dichotomy between the weather on both sides of the planet, and huge differences in cloud coverage, and that changes our whole picture of the planet.”

James Webb Peers Through Alien Clouds

The clearer evening skies gave scientists an opportunity that had previously been impossible with older telescopes such as Hubble. By isolating the cloud free side of the planet, researchers could directly examine the atmosphere itself instead of averaging cloudy and clear regions together.

“With the Hubble telescope, when we used to do this type of observation, we got an average view of the whole planet with data from the clouds and the atmosphere squished together and indistinguishable,” said first author Sagnick Mukherjee, a postdoctoral fellow at Arizona State University who was a student at Johns Hopkins and UC Santa Cruz at the time of the research. “This approach with the JWST lets us localize our observations, which helped us see the cloud cycle.”

The clearer data also solved a long standing mystery about the planet’s chemistry. Earlier measurements suggested WASP-94A b contained hundreds of times more oxygen and carbon than Jupiter, something that did not fit with existing theories of planet formation.

The new observations paint a very different picture. Scientists now estimate the planet contains only about five times more oxygen and carbon than Jupiter, making it far more similar to the giant planet in our own solar system than previously believed.

A New Window Into Alien Atmospheres

Hot Jupiters are giant gas planets that orbit extremely close to their stars, even closer than Mercury orbits the Sun. Because of their intense heat and radiation, these planets provide scientists with ideal natural laboratories for studying atmospheric chemistry and cloud behavior under extreme conditions.

After studying WASP-94A b, the research team examined eight additional Hot Jupiters and identified similar cloud cycling on two more worlds: WASP-39 b and WASP-17 b.

Next, researchers plan to expand the search using a larger JWST observing program that will investigate cloud cycles across many different exoplanets, including an unusual gas giant that travels through the habitable zone on an eccentric orbit.

The Fermi mission is part of NASA’s network of observatories designed to track changing events across the universe and help scientists better understand how cosmic phenomena work.

“For nearly 20 years, astronomers have searched Fermi data for gamma-ray signals from thousands of supernovae, and while a few intriguing hints have been reported, none were definitive until now,” study lead Fabio Acero at the French National Centre for Scientific Research (CNRS) and the University of Paris-Saclay.

The findings were published in the journal Astronomy & Astrophysics.

Rare Supernova Emits Powerful Gamma Rays

Core-collapse supernovae occur when a massive star exhausts the fuel needed to support its core. Without that energy source, the core collapses under gravity and triggers a violent explosion. Depending on conditions, the collapse can leave behind either a neutron star or a black hole. The rest of the star is blasted outward into space as an expanding cloud of extremely hot gas.

Over the past two decades, astronomers have identified nearly 400 unusually powerful examples known as superluminous supernovae. These rare explosions can shine at least 10 times brighter in visible light than ordinary supernovae.

In 2024, researchers led by Li Shang at Anhui University in Hefei, China, suggested that Fermi’s Large Area Telescope may have detected gamma rays from one of these events years after the explosion occurred.

The object, called SN 2017egm, erupted in the galaxy NGC 3191, about 440 million light-years away in the constellation Ursa Major. Even from that enormous distance, it remains one of the closest superluminous supernovae ever observed from Earth.

“We searched for gamma rays from the six nearest superluminous supernovae seen during the first 16 years of Fermi’s mission,” said Guillem Martí-Devesa, a researcher previously at the University of Trieste in Italy and now a fellow at the Institute of Space Sciences in Barcelona, Spain. “Only SN 2017egm shows evidence for gamma rays, confirming earlier hints that some supernovae can be as luminous in gamma rays as they are in visible light. This opens up a new window for studying these fascinating events.”

Magnetars May Be the Hidden Engine

Scientists have long debated what gives superluminous supernovae their extraordinary brightness. One leading explanation involves magnetars, which are neutron stars with the strongest magnetic fields known in the universe. Their magnetic fields can be up to 1,000 times stronger than those of ordinary neutron stars, reaching strengths roughly 10 trillion times greater than a refrigerator magnet.

To investigate further, the team closely examined both the visible light and gamma-ray signals from SN 2017egm and compared the observations with different theoretical models.

A model created by co-authors Indrek Vurm at the University of Tartu in Estonia and Brian Metzger at Columbia University in New York City followed how radiation and particles from a newborn magnetar would move through the expanding supernova debris.

Researchers believe a newly formed magnetar can rotate several hundred times every second. That incredible speed generates a powerful flow of electrons and positrons, which are the antimatter versions of electrons. Together, these particles create a huge cloud of high-energy material called a magnetar wind nebula.

Inside this nebula, particle interactions can generate gamma rays in several ways. Electrons and positrons can collide and transform into gamma-ray photons, while gamma rays themselves can collide and create new particles. As these interactions continue, much of the gamma-ray energy becomes trapped inside the supernova debris and is converted into lower-energy visible light, helping make the explosion exceptionally bright.

Gamma Rays Escape Months Later

“About three months after the collapse, as the supernova debris expands and cools, the gamma rays can begin to leak out,” Acero said. “This magnetar model best reproduces the supernova’s luminosity and the arrival time of its gamma rays during the first months, but we see room for improvement at later times, when the visible light fades quite irregularly.”

The researchers suggest that additional processes likely influenced the supernova during its long decline in brightness. These may include material falling back toward the magnetar and collisions between the expanding blast wave and matter expelled by the star centuries before it exploded.

The team also explored whether future observatories could detect similar events. They found that the upcoming Cerenkov Telescope Array Observatory should be capable of spotting supernovae like SN 2017egm from distances up to about 500 million light-years away with roughly 50 hours of observation time.

Scientists say future cooperation between ground-based observatories and NASA’s space telescopes will help reveal even more about these violent stellar explosions and the extreme objects hidden inside them.

“The magnetar central engine mechanism discussed in this paper builds upon a lot of observational and theoretical advances in magnetars over the last 20 years,” said Judy Racusin, a deputy project scientist for the Fermi mission at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Observing gamma rays from supernovae will give us a new way to explore their inner workings.”

Researchers found that combining guava juice with iron supplements appeared to improve hemoglobin levels more effectively than taking iron supplements alone. The findings suggest the tropical fruit juice could become a useful addition to nutrition programs aimed at preventing iron deficiency anemia in regions where the condition is widespread.

Iron deficiency anemia is especially common among pregnant women and adolescent girls in many developing countries. The condition can lead to fatigue, weakness, poor concentration, pregnancy complications, and increased risk of serious illness or death.

Why Guava Juice May Help

Guava is naturally rich in vitamin C, which helps the body absorb iron from plant based foods more efficiently. According to the researchers, guava contains up to four times more vitamin C per 100 grams than oranges.

In addition to vitamin C, guava also provides vitamin A, folate, dietary fiber, and small amounts of iron.

Several smaller studies conducted in Indonesia had already suggested that drinking guava juice might raise hemoglobin levels, but researchers said the overall evidence had not previously been reviewed together in a comprehensive analysis.

Review Examined 17 Studies

To better understand the potential benefits, researchers analyzed studies published in English since 2000. They identified 17 eligible studies, including 15 quasi experimental studies and two randomized controlled trials.

Six studies focused on teenage girls, while 11 involved pregnant women. Most of the studies examined guava juice alongside iron supplementation.

The researchers combined data from 12 studies involving 235 women and adolescent girls. Overall, participants experienced an average increase in hemoglobin levels of 1.71 g/dl after consuming guava juice.

When researchers looked at the groups separately, teenage girls showed an average increase of 1.52 g/dl, while pregnant women experienced an average increase of 1.84 g/dl.

Guava Juice Plus Iron Supplements Performed Better

Five of the studies directly compared women who took iron supplements alone with women who took iron supplements along with guava juice. Each group included 102 participants.

The results showed that the combination approach led to hemoglobin levels that were, on average, 1.29 g/dl higher than iron supplements alone.

“An increase of 1-2 g/dl may shift individuals from mild or moderate anemia to non-anemic categories, improving fatigue, cognitive function, and productivity outcomes,” suggest the researchers.

The team noted several important limitations. All of the studies were conducted in Indonesia, and there were major differences in study design, guava type, dosage, intervention length, and participant characteristics.

Researchers also cautioned that most of the evidence came from quasi experimental studies rather than stronger randomized clinical trials. In addition, the studies did not include long term follow up, making it unclear how long the benefits may last.

Could Guava Juice Become Part of Public Health Programs?

Despite the limitations, researchers believe guava juice could still become a practical and low cost nutritional strategy for reducing mild to moderate anemia.

“Integrating guava juice into school nutrition programs, antenatal care packages, or community health initiatives could represent a feasible approach to address mild-to-moderate anemia, aligning with the United Nations’ Decade of Action on Nutrition (2016-2025), which emphasizes dietary diversification and locally sourced nutrient-rich foods,” they point out.

They added that guava juice is already widely accepted culturally across many parts of Asia and is relatively inexpensive, making it a potentially sustainable public health tool.

“Given its nutritional richness, affordability, and cultural acceptance across Asia, guava juice offers a promising low-cost intervention. Strengthening local supply chains, standardizing formulations and embedding such dietary approaches within public health nutrition programs could collectively contribute to more sustainable anemia control,” they add.

Professor Sumantra Ray, chief scientist & executive director, NNEdPro Global Institute for Food, Nutrition and Health, which co-owns BMJ Nutrition Prevention & Health, said the findings support existing knowledge about vitamin C improving iron absorption.

“This study builds on the established role of dietary sources high in vitamin C to enhance iron absorption and improve the effectiveness of iron supplementation,” he comments.

However, he also emphasized that more rigorous research is still needed before guava juice could be recommended as a substitute for conventional anemia treatment.

“But quasi-experimental research, the wide variation in study design, small sample sizes, and limited length of follow-up mean that caution is required when interpreting the findings. Without further rigorous research, defining the best therapeutic dose and period of use, guava juice can’t be recommended as an alternative to conventional treatment in those at risk of iron deficiency anemia,” he adds.

Current medicines can ease some symptoms, and recent Alzheimer’s therapies such as lecanemab and donanemab can slow decline in certain people with early disease, but they do not restore lost memories or rebuild damaged brain tissue. That is why researchers are pursuing another ambitious idea: helping the brain replace neurons that have been lost.

A Vitamin Better Known for Blood and Bones

Vitamin K is best known for its role in blood clotting and bone health. In recent years, however, scientists have also linked it to brain protection and neuronal differentiation, the process by which immature neural cells become functioning neurons.

One form of vitamin K, menaquinone 4 (MK-4), is naturally active in the body. Even so, its effects may not be strong enough on their own for future use in regenerative medicine aimed at neurodegenerative disease.

In work published online in ACS Chemical Neuroscience on July 03, 2025, researchers from Shibaura Institute of Technology in Japan created vitamin K analogues designed to be more active in the nervous system. The study was led by Associate Professor Yoshihisa Hirota and Professor Yoshitomo Suhara of the Department of Bioscience and Engineering.

Dr. Hirota explains, “The newly synthesized vitamin K analogues demonstrated approximately threefold greater potency in inducing the differentiation of neural progenitor cells into neurons compared to natural vitamin K. Since neuronal loss is a hallmark of neurodegenerative diseases such as Alzheimer’s disease, these analogues may serve as regenerative agents that help replenish lost neurons and restore brain function.”

Building a Stronger Brain Active Compound

To make vitamin K more potent, the team synthesized 12 hybrid vitamin K homologs. Some were linked to retinoic acid, an active metabolite of vitamin A that is known to promote neuronal differentiation. Others included a carboxylic acid moiety or a methyl ester side chain. The researchers then compared how strongly these compounds encouraged neural progenitor cells to become neurons.

Vitamin K and retinoic acid influence gene activity through different receptors. Vitamin K acts through the steroid and xenobiotic receptor (SXR), while retinoic acid acts through the retinoic acid receptor (RAR). When the team tested the compounds in mouse neural progenitor cells, the hybrid molecules preserved the biological activity of both vitamin K and retinoic acid.

The researchers also measured microtubule associated protein 2 (Map2), a marker associated with neuronal growth. One compound stood out. It combined the retinoic acid structure with a methyl ester side chain and showed threefold higher neuronal differentiation activity than the control, along with significantly stronger activity than natural vitamin K compounds. The researchers referred to it as Novel vitamin K analog (Novel VK).

A Surprising Signal in the Brain

The team then investigated how vitamin K might be producing these neuroprotective effects. They compared gene expression in neural stem cells treated with MK-4, which promotes neuronal differentiation, with cells treated using a compound that suppresses the process.

The analysis pointed to metabotropic glutamate receptors (mGluRs), which appeared to help drive vitamin K induced neuronal differentiation through downstream epigenetic and transcriptional regulation. The effect of MK-4 was specifically tied to mGluR1.

That connection is important because mGluR1 has already been linked to synaptic transmission, the communication between neurons. Mice lacking mGluR1 show motor and synaptic problems, features that overlap with the kinds of dysfunction seen in neurodegenerative diseases.

Crossing Into the Brain

To explore whether the vitamin K compound could interact with mGluR1, the researchers used structural simulations and molecular docking studies. Their results suggested that Novel VK had stronger binding affinity for mGluR1 than MK-4.

They also tested how well Novel VK entered cells and converted into bioactive MK-4. Inside cells, MK-4 levels rose in a concentration dependent way. Novel VK also converted into MK-4 more easily than natural vitamin K.

Mouse experiments added another key finding. Novel VK showed a stable pharmacokinetic profile, crossed the blood brain barrier, and produced higher MK-4 concentrations in the brain than the control.

Why the Finding Matters

The work highlights a possible route toward therapies that do more than manage symptoms. By pushing neural progenitor cells toward becoming neurons, vitamin K based compounds could one day contribute to strategies aimed at slowing, delaying, or potentially reversing parts of neurodegeneration.

That remains a long term goal. The findings are based on cell studies and mouse experiments, not human trials. No vitamin K derived drug has yet been shown to repair the brains of people with Alzheimer’s, Parkinson’s, or Huntington’s disease. Still, the results give researchers a clearer target, especially the mGluR1 pathway, for developing future brain repair therapies.

The broader Alzheimer’s field is already moving beyond purely symptom based treatment. FDA approved anti amyloid therapies now target disease biology in early Alzheimer’s, though they are not cures and do not restore lost memory or cognitive function. A regenerative approach, if eventually proven safe and effective, would aim at a different challenge: replacing or restoring damaged neural cells.

Dr. Hirota says, “Our research offers a potentially groundbreaking approach to treating neurodegenerative diseases. A vitamin K-derived drug that slows the progression of Alzheimer’s disease or improves its symptoms could not only improve the quality of life for patients and their families but also significantly reduce the growing societal burden of healthcare expenditures and long-term caregiving.”

The hope is that this line of research will eventually move from promising laboratory results toward clinically meaningful treatments for people living with neurological disease.

About Associate Professor Yoshihisa Hirota from SIT, Japan

Dr. Yoshihisa Hirota is an Associate Professor at the Shibaura Institute of Technology in the Department of Bioscience and Engineering, College of Systems Engineering and Science. He has also worked internationally as a Visiting Scholar at the University of Cincinnati.

His research centers on Medicinal Science and Nutritional Biochemistry, with a special focus on how fat soluble vitamins and nucleic acids function in biological systems. Dr. Hirota has published 56 papers, and his work connects molecular biology with nutrition in pursuit of better health care solutions and longer healthy life expectancy.

About Professor Yoshitomo Suhara from SIT, Japan

Dr. Yoshitomo Suhara is a Professor at the Shibaura Institute of Technology in the Department of Bioscience and Engineering, College of Systems Engineering and Science.

His work focuses on medicinal chemistry and drug discovery, especially the creation of bioactive small molecules derived from fat soluble vitamins such as vitamins D and K. He has authored more than 100 peer reviewed publications and several patent applications. His multidisciplinary projects include neurogenic compounds that promote neuronal differentiation, antiviral agents, and novel anti cancer molecules.

Funding Information

This study was partly supported by a fund for the Mishima Kaiun Memorial Foundation and the Suzuken Memorial Foundation, KOSÉ Cosmetology Research Foundation, Koyanagi Foundation, Research Grants from the Toyo Institute of Food Technology, the Science Research Promotion Fund and the Takahashi Industrial and Economic Research Foundation.

Additional support came from a Fund for the Promotion of Joint International Research (Fostering Joint International Research (A)) [grant number 18KK0455] and a Grant in Aid for Scientific Research (C) [grant numbers 20K05754 and 18K11056, 21K11709, and 24K14656], Grant in Aid for Early Career Scientists [grant number 23K14091] from the Japan Society for the Promotion of Science (JSPS).

The maneuver sends Psyche on a direct route toward its target in the asteroid belt between Mars and Jupiter. After the flyby, engineers confirmed the spacecraft was exactly where it needed to be by analyzing radio communications between Psyche and NASA’s Deep Space Network (DSN), the agency’s worldwide communications system for deep space missions.

“Although we were confident in our calculations and flight plan, monitoring the DSN’s Doppler signal in real time during the flyby was still exciting,” said Don Han, Psyche’s navigation lead at NASA’s Jet Propulsion Laboratory in Southern California. “We’ve confirmed that Mars gave the spacecraft a 1,000 mile-per-hour boost and shifted its orbital plane by about 1 degree relative to the Sun. We are now on course for arrival at the asteroid Psyche in summer 2029.”

Psyche Captures Rare Crescent Views of Mars

The Mars encounter also gave the mission team an opportunity to fully test Psyche’s scientific instruments before the spacecraft reaches the asteroid. During the days leading up to the flyby and at closest approach, engineers powered up the spacecraft’s imagers, magnetometers, and gamma-ray and neutron spectrometer.

As Psyche approached Mars, the planet appeared as a narrow crescent because of the angle between the spacecraft, Mars, and the Sun. Images taken by the spacecraft’s multispectral camera showed the crescent stretching farther around the planet than expected. Scientists say sunlight scattering through Mars’ dusty atmosphere likely caused the effect. Near closest approach, the spacecraft rapidly photographed the Martian surface as it crossed from the night side of the planet into daylight.

“We’ve captured thousands of images of the approach to Mars and of the planet’s surface and atmosphere at close approach. This dataset provides unique and important opportunities for us to calibrate and characterize the performance of the cameras, as well as test the early versions of our image processing tools being developed for use at the asteroid Psyche,” said Jim Bell, the Psyche imager instrument lead at Arizona State University (ASU) in Tempe. “As the spacecraft continues its journey after the flyby, we’ll continue calibration imaging of Mars for the rest of the month as it recedes into the distance.”

Bell also leads the Mastcam-Z imaging investigation for NASA’s Perseverance rover mission. Several additional Mars missions contributed supporting observations during the flyby, including NASA’s Mars Reconnaissance Orbiter, 2001 Mars Odyssey orbiter, and Curiosity rover, along with ESA’s (European Space Agency’s) Mars Express and ExoMars Trace Gas Orbiter.

Testing Instruments Before Arrival at Asteroid Psyche

The flyby also allowed scientists to collect valuable calibration data from Psyche’s other instruments. Early readings from the spacecraft’s magnetometers may have detected Mars’ bow shock, the region where the solar wind interacts with the planet’s magnetic environment.

At the same time, the gamma-ray and neutron spectrometer team gathered measurements that can now be compared with decades of existing Mars data.

With Mars now behind it, Psyche will resume using its solar-electric propulsion system to continue toward the asteroid belt. The spacecraft is scheduled to arrive at asteroid Psyche in August 2029.

Scientists believe Psyche could be the exposed partial core of an ancient planetesimal, one of the building blocks that formed planets early in the solar system’s history. The asteroid measures about 173 miles (280 kilometers) across at its widest point.

Once it arrives, the spacecraft will orbit Psyche at several different altitudes while mapping the surface and collecting scientific data. If the asteroid truly represents the metallic interior of an early world, it could provide researchers with a rare opportunity to study material similar to what lies deep inside rocky planets such as Earth.

“We’ve been anticipating the Mars flyby for years, but now it’s complete. We can thank the Red Planet for giving our spacecraft a critical gravitational slingshot farther into the solar system,” said Lindy Elkins-Tanton, principal investigator for Psyche at the University of California, Berkeley. “Onward to the asteroid Psyche!”

About NASA’s Psyche Mission

The Psyche mission is led by ASU. NASA’s Jet Propulsion Laboratory (JPL), a division of Caltech in Pasadena, manages mission operations, engineering, testing, and system integration.

The spacecraft chassis for Psyche’s high power solar-electric propulsion system was provided by Intuitive Machines in Palo Alto, California. ASU oversees operation of the spacecraft’s imaging instrument in partnership with Malin Space Science Systems in San Diego, which helped design, build, and test the cameras.

Psyche is the 14th mission selected for NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. NASA’s Launch Services Program at Kennedy Space Center in Florida managed launch services for the mission.

Now, researchers led by scientists at the University of Wisconsin-Madison believe they may have uncovered the missing piece of the puzzle.

In a new study published in Nature, the team used extremely detailed computer simulations to study plasma flows. Their results suggest that large magnetic fields can emerge when turbulent plasma develops organized jet-like flows. The discovery introduces a new explanation for how cosmic magnetic fields form and could help scientists better understand everything from black hole formation to space weather near Earth.

“Magnetic fields across the cosmos are large-scale and ordered, but our understanding of how these fields are generated is that they come from some kind of turbulent motion,” says the study’s lead author Bindesh Tripathi, a former UW-Madison physics graduate student and current postdoctoral researcher at Columbia University. “Given that turbulence is known to be a destructive agent, the question remains, how does it create a constructive, large-scale field?”

Searching for Order in Cosmic Turbulence

Before focusing on three-dimensional (3D) magnetic fields, Tripathi had studied systems involving fluid flows and two-dimensional (2D) magnetic fields. While examining images and videos of 3D magnetic turbulence, he noticed that large-scale magnetic structures resembled the shapes of large-scale flows.

However, applying fluid dynamics directly to magnetic fields was not straightforward. Fluid flow problems can often be simplified into two dimensions, but magnetic field generation must be solved in full 3D space, making the calculations far more difficult.

To tackle the challenge, the researchers changed two important aspects of previous studies.

The first involved adding a constantly renewed velocity gradient into the simulations. A velocity gradient occurs when different parts of a system move at different speeds. For example, a cyclist who suddenly hits a curb experiences a sharp velocity gradient when the bike stops but the rider’s momentum continues forward. Similar effects occur throughout the universe, including inside the Sun and during neutron star mergers. The team suspected these gradients could play a major role in shaping magnetic fields.

Massive Supercomputer Simulations Reveal a Pattern

The second major step was computational power. The researchers carried out what may be the most detailed simulation yet of magnetic fields interacting with unstable velocity gradients. Their model used 137 billion grid points in 3D space.

In total, the team performed roughly 90 simulations, producing 0.25 petabytes of data and consuming nearly 100 million CPU hours on Purdue University’s Anvil supercomputer.

“We start our simulations with a flow that has a velocity gradient, then we add some tiny perturbations, like moving one fluid particle infinitesimally, we let that perturbation propagate over the system and grow, and then analyze the data over time,” Tripathi says. “Initially, these perturbations lead to turbulent flows and magnetic fields in small-scale structures, then, over time, they emerge into larger, ordered structures.”

When the researchers repeated the simulations without maintaining the large-scale velocity gradient, the organized magnetic structures never formed. Instead, the system remained chaotic and disordered.

“So that’s really the main key: to have a steady, large-scale gradient in velocity,” he emphasizes.

Solving a Long-Standing Magnetic Field Problem

Scientists have studied magnetic dynamos, the processes that generate magnetic fields, for roughly 70 years. Yet most theoretical models have struggled to produce the large, ordered magnetic structures that astronomers actually observe in space.

Adds Paul Terry, physics professor at UW-Madison and senior author of the study: “Magnetic field generation via dynamos has been extensively studied for 70 years, with the frustrating result that the generated fields almost always end up at small scales and highly disordered, unlike observations. This work, therefore, potentially resolves a long-standing issue.”

Although the new theory cannot be directly tested in distant cosmic environments, earlier laboratory experiments appear to support the findings. In 2012, researchers at the Wisconsin Plasma Physics Laboratory observed magnetic field behavior that existing theories could not explain. The new model developed by Tripathi and his colleagues aligns more closely with those puzzling experimental results.

Implications for Black Holes, Neutron Stars, and Space Weather

The findings could have important implications across astrophysics.

“This work has the potential to explain the magnetic dynamics relevant in, for example, neutron star mergers and black hole formation, with direct applications to multimessenger astronomy,” Tripathi says. “It may also help better understand stellar magnetic fields and predict gas ejections from the Sun toward the Earth.”

The research was supported by the National Science Foundation (2409206) and U.S. Department of Energy (DE-SC0022257) through the DOE/NSF Partnership in Basic Plasma Science and Engineering. The Anvil supercomputer at Purdue University was used through allocation TG-PHY130027 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program, supported by the National Science Foundation (2138259, 2138286, 2138307, 2137603 and 2138296).