SPACE/COSMOS

Galaxy-killing wind discovered in the early universe

Royal Astronomical Society

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

Astronomers have discovered a ‘galaxy-killing wind’ that may explain why there are far more massive ‘dead’ galaxies than expected in the early universe.

This wind, powered by cosmic collisions of galaxies, could quickly blow away all the fuel for new stars, leaving the galaxy on the brink of death and helping to solve one of the biggest mysteries in modern astrophysics.

The theory is much simpler than some of the other explanations put forward since 2022, when the James Webb Space Telescope (JWST) gave us our first clear glimpse of the early universe. Among them was that dark energy may have been stronger in the early universe than current theories predict, allowing galaxies to grow and die faster.

Researchers behind the new study, published today in Monthly Notices of the Royal Astronomical Society: Letters, used JWST to show that galaxy-killing winds can be powered by the same intense star-formation that causes galaxies to grow rapidly, explaining why these early galaxies live fast and die young.

“Dense regions of the universe are like very active cities,” said lead author Dr Rebecca Davies, of the Swinburne University of Technology in Melbourne, who carried out the study with Associate Professor Deanne Fisher.

“Galaxies collide and undergo frenzied bursts of star-formation. But when the biggest stars burn out, they explode as supernovae, launching powerful winds that blast away the very gas galaxies need to keep forming stars.”

Galaxy winds have long been considered prime suspects for the deaths of massive galaxies, but observational evidence was lacking.

Using JWST and the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope, the Swinburne team imaged a galaxy one billion years after the Big Bang in the midst of a rapid growth spurt.

This galaxy, called CRISTAL-02, is forming stars twice as fast as other similar-sized galaxies. The extremely sensitive observations revealed a huge plume of cold gas extending far away from CRISTAL-02. This plume is almost as long as the galaxy itself, which is a telltale sign that gas is being driven out of the galaxy.

“The galaxy has a powerful wind that is ejecting material twice as fast as the galaxy forms stars,” Dr Davies added.

“If this rapid blowout continues, the galaxy could be dead in less than 50 million years: explaining the origin of the mysterious massive dead galaxies in the early universe.”

CRISTAL-02 is not a single galaxy, but multiple galaxies in the final stages of a cosmic collision. During such collisions, gas funnels towards the galaxy centres, triggering strong bursts of star formation.

Dr Davies believes that other galaxies will likely face a similar fate to CRISTAL-02, undergoing frenzied bursts of star-formation, followed by powerful winds that lead them to their deaths.

“Almost half of early massive galaxies are interacting with other nearby galaxies, suggesting this isn’t a quirk but a widespread cosmic phenomenon,” she said.

“If many early galaxies collide and experience rapid growth, then it may not be surprising that we see so many dead galaxies in the early universe.

“CRISTAL-02 offers a natural solution to the mystery of why these massive galaxies live fast and die young.”

ENDS

---

Media contacts

Sam Tonkin

Royal Astronomical Society

Mob: +44 (0)7802 877 700

press@ras.ac.uk

---

Science contacts

Dr Rebecca Davies

Swinburne University of Technology

rdavies@swin.edu.au

---

Images & captions

 

CRISTAL-02

Caption: An artist’s impression of the galaxy CRISTAL-02, with a huge plume of cold gas extending away from it. This plume is almost as long as the galaxy itself, which is a telltale sign that gas is being driven out of the galaxy.

Credit: Joshua Worth via Creative Commons CC-BY license

---

Further information

The paper 'Multiphase images of a powerful supernova-driven wind in the early Universe’ by Davies et al. has been published in Monthly Notices of the Royal Astronomical Society: Letters. DOI: 10.1093/mnras/stag874

---

Notes for editors

About the Royal Astronomical Society

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.

The RAS organises scientific meetings, publishes international research journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

The RAS accepts papers for its journals based on the principle of successful peer review, following which experts on the Editorial Boards accept the papers for publication. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

Keep up with the RAS on Instagram, Bluesky, LinkedIn, Facebook and YouTube.

Download the RAS Supermassive podcast

---

Journal

Monthly Notices of the Royal Astronomical Society

DOI

10.1093/mnras/stag874 

Article Title

'Multiphase images of a powerful supernova-driven wind in the early Universe’

Article Publication Date

10-Jun-2026

SPACE/COSMOS

FAST discovers a rare millisecond pulsar with an extremely circular orbit

Science China Press

LinkedInWeChatBlueskyMessageWhatsAppEmail

Pulsars are ultra-dense neutron stars left behind after massive stars explode. They spin at incredible speeds, emitting regular beams of electromagnetic radiation. When these beams sweep past Earth, astronomers detect periodic signals, much like flashes from a lighthouse.

Recently, China's Five-hundred-meter Aperture Spherical radio Telescope (FAST) — has discovered a new pulsar of significant research value, named PSR J1810−0623. This pulsar not only spins extremely fast, but its formation history also appears to record a long and complex "binary evolution story."

PSR J1810−0623 has a rotation period of just 4.55 milliseconds, meaning it spins about 220 times every second. Astronomers believe that the vast majority of millisecond pulsars are not born spinning this fast; rather, they are accelerated through long-term interactions with a companion star: material from the companion star falls onto the neutron star, transferring angular momentum and causing it to spin faster and faster. This process is known as "recycling." Through precise observations spanning six and a half years, the research team found that PSR J1810−0623 has undergone an extremely thorough recycling process. Not only is its rotation speed exceptionally high, but its surface magnetic field has also decayed to only about 100 million Gauss.

PSR J1810−0623 has a companion star, and the two orbit their common center of mass every 15.4 days. Based on observational calculations, this companion star has a mass of about 0.64 times that of the Sun and is likely a carbon-oxygen white dwarf. This clue reveals the origin of PSR J1810−0623: it was likely born in a "moderate-mass X-ray binary system". Over vast stretches of time, the companion star continuously transferred material to the neutron star, not only causing the latter to spin rapidly but also eventually depleting its own outer layers, leaving behind the white dwarf remnant we see today. This formation pathway is uncommon in the Milky Way, making such systems particularly valuable.

What particularly intrigues researchers is that the orbit of this binary system is nearly a perfect circle. The eccentricity of PSR J1810−0623's orbit is only about 0.000015, representing an orbit so close to circular that its elliptical shape is almost undetectable. Generally, long-term, stable mass transfer between binary stars gradually smooths out orbital irregularities, making the orbit increasingly circular. This characteristic is similar to a few known special systems, such as the famous PSR J1614−2230. However, the orbit of PSR J1810−0623 is even rounder, providing a new observational benchmark for testing binary evolution theories.

Beyond revealing binary evolution processes, this newly discovered pulsar can also help scientists study the Milky Way itself. The research team used the polarization properties of its radio signals to measure magnetic field information along the line of sight, thereby providing new data points for mapping the Galactic magnetic field structure.

In the future, as FAST and other radio telescopes continue long-term timing observations, scientists hope to further determine the true mass of this neutron star and even test gravitational theories through more precise orbital measurements. For studying pulsar recycling mechanisms, binary system evolution, and the structure of the Milky Way, PSR J1810−0623 will prove to be an immensely valuable "natural laboratory".

---

Journal

Science China Physics Mechanics and Astronomy

DOI

10.1007/s11433-026-2951-1 

Method of Research

Observational study

TRACERS uses speedy electrons to trace solar energy’s path to Earth

First published results from Iowa-led NASA mission reveal new details of sun-Earth interaction

University of Iowa

Facebook

XLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

A University of Iowa-led research team has documented how energy from the sun interacts with Earth’s magnetic field and moves closer to our planet, using detailed electron measurements. In this image, speedy electrons act like messengers to convey information about those interactions, called magnetic reconnection, tens of thousands of miles from Earth’s surface.

view more 

Credit: Jasper Halekas lab, University of Iowa

Physicists led by the University of Iowa have documented in the finest detail to date how energy from the sun interacts with Earth’s magnetic field, which could yield greater insights into solar effects on Earth that drive space weather.

In a new study, the researchers measured the velocities and concentrations of electrons in low-Earth orbit at locations called cusps, which act like conduits for charged particles from the sun to enter Earth’s ionosphere, the upper reaches of our planet’s atmosphere. Through those detailed measurements, the researchers were able to more precisely map the travel pattern of solar energy from magnetic reconnection — solar energy’s first encounter with Earth’s magnetic field tens of thousands of miles from Earth’s surface — to its interactions at cusps a few hundred miles above our planet.

“With magnetic reconnection, we don't really know how it varies at a fine scale. We have a hunch that it’s either varying in time or varying spatially,” says Jasper Halekas, professor in the Department of Physics and Astronomy at Iowa and the study’s corresponding author. “Our electron edge measurements reveal for the first time how these processes vary on small time and spatial scales at the edge of the cusp, helping us to better understand the efficiency of the sun-Earth coupling.”

The results come from TRACERS, the approximately $170 million mission funded by NASA and the largest external research award in University of Iowa history. Launched in July 2025, twin satellites swoop through low-Earth orbit, sampling electrons, ions, plasma, and other elements part of the interactions between the sun and the Earth. 

“This is important because magnetic reconnection is how the energy from the sun gets into Earth’s system,” Halekas says. “It’s important to know the duty cycle of that reconnection — is it happening continuously, or is it sort of turning on and off?”

Electrons are key to better understanding magnetic reconnection events and how they reverberate closer to Earth. Because of their nearly nonexistent mass and high energies, think of them as ultra-speedy messengers, delivering the first news about magnetic reconnection some 30,000 miles away at the edges of Earth’s magnetic bubble and portending the ripple effects at cusps farther downstream in Earth’s ionosphere.

“The electrons are saying, magnetic reconnection is taking place way out here, and we’re letting you know that there’s going to be this wave of mass and energy coming to us,” Halekas explains.

The researchers cataloged 149 cusp encounters by one of the TRACERS spacecraft; 57 of those encounters showed characteristic electron dispersion signatures at the equatorward edge. The observations came from data collected by the Analyzer for Cusp Electrons instrument (ACE), designed and built at Iowa.

“The equatorward edge is the leading edge of the cusp, where the solar wind energy and plasma can first reach the ionosphere,” says Halekas, principal investigator for the ACE instrument. “The electron and ion signatures we see there are the proof we’re seeing the effects of magnetic reconnection.” 

The study, “Electron dispersion at the electron edge of the Earth’s magnetospheric cusp,” was published online May 19 in the journal Geophysical Research Letters.

Contributing authors from Iowa are Sarah Henderson, Scott Bounds, Aidan Moore, Ivar Christopher, David Miles, Connor Feltman, George Hospodarsky, Allison Jaynes, Brendan Powers, and Shirsh Soni.

Other authors are Suranga Ruhunusiri and Karlheinz Trattner, from the University of Colorado-Boulder; John Bonnell and Marit Øieroset, from the University of California-Berkeley; Brandon Burkholder, from the University of Maryland-Baltimore County and NASA Goddard Space Flight Center; Iver Cairns, from the University of Sydney in Australia; Li-Jen Chen, Hyunju Connor, and John Dorelli, from NASA Goddard Space Flight Center; Ian DesJardin and Dibyendu Sur, from Catholic University of America and NASA Goddard Space Flight Center; Stephen Fuselier, from Southwest Research Institute and the University of Texas-San Antonio; Katherine Goodrich, from West Virginia University; James Labelle, from Dartmouth College; Steven Petrinec, from Lockheed Martin Advanced Technology Center, in Palo Alto, California; and Robert Strangeway, from the University of California-Los Angeles.

---

Journal

Geophysical Research Letters

DOI

10.1029/2026GL122699 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Electron Dispersion at the Electron Edge of the Earth's Magnetospheric Cusp

Astronaut Victor Glover is still trying to find the spiritual words to describe his Moon mission

(RNS) — 'At the end of it, when we were just responding totally instinctually, we talked a lot about God,' Glover told RNS in a recent interview, referring to the Artemis II crew.

Jack Jenkins
June 12, 2026 

RNS


(RNS) — On a humid evening in late March, Victor Glover huddled with his fellow Artemis II astronauts to have what the spacefarers called their “ultimate dinner.” It was their last full meal before embarking on their historic journey around the Moon — the first human-crewed visit to Earth’s silver satellite since 1972.

After Glover finished his spread of lamb chops, spinach and sweet potatoes, the cook returned with something else: Communion elements. The cook, a Christian himself, then sat next to Glover and Canadian astronaut Jeremy Hansen as the men paused to pray before observing the Christian sacrament together.

“I prayed and I pleaded that God accepts that I do this for the mission,” Glover, who worships with Churches of Christ congregations in Texas, told Religion News Service in a recent video interview.

It was a quiet moment of religious ritual shortly before a rocket launch so explosively loud that, even a mile away, the boom rivaled the sound of standing near a screaming jet engine. The Space Launch System that carried the Orion spacecraft then catapulted Glover, the pilot for the mission, and his fellow Artemis II crew members into space, where they soared around the Moon and back in a gaping 252,756 mile arc that took them farther away from the Earth than any human beings in history.

But as millions back home marveled at the nine-day mission’s breathtaking photographs and technical accomplishments, Glover said the journey was also steeped in spiritual significance, from blastoff to splashdown.

The Artemis II crew captured this view of an Earthset on April 6, 2026, as they flew around the Moon. (Photo courtesy of NASA) TOP PHOTO: NASA astronaut and Artemis II Pilot Victor Glover peers out the window of the Orion spacecraft during the Artemis II lunar flyby on April 6, 2026. (Photo courtesy of NASA)

“At the end of it, when we were just responding totally instinctually, we talked a lot about God,” he said, referring to the crew. “We talked a lot about creation and the beauty of the universe and the cosmos.”

Glover, 50, said just talking about the mission — even among the Artemis II crew members in their brief reunions between press junkets — has been a challenge. Multiple times in his interview with RNS, Glover admitted to struggling to articulate his thoughts on aspects of the flight, which included witnessing a spectacular solar eclipse rarely seen from space that spurred mission commander Reid Wiseman to quip to Glover, “I don’t think humanity has evolved to the point of being able to comprehend what we are looking at right now.”

“At the end of it, when we were just responding totally instinctually, we talked a lot about God ... We talked a lot about creation and the beauty of the universe and the cosmos.”Victor Glover

While he feels his faith has “definitely grown” through the journey, Glover said the inability to find the right words is something he has come to embrace as a kind of spiritual posture.

“I don’t have to be quick to put words on it and label the moments in the mission,” he said, later adding: “I’m actually getting comfortable not having to answer things. You have questions? Let’s talk about the question.”

Video Player


03:08


A faith that dwells among the stars

The clear impact of the mission on Glover is striking given his already ample experience as an astronaut. In 2020, he was among the first astronauts to fly aboard the Dragon Capsule, a commercial spacecraft created by Space X, to the International Space Station, where he and three other astronauts lived, suspended above the Earth, for 167 days. In an interview with the Christian Chronicle before the mission, he said he planned to bring Communion cups aboard the ISS, hoping to continue worshipping virtually with his faith community.

It’s hardly the first time an astronaut has engaged in religious ritual while in space (Buzz Aldrin, a Presbyterian, took Communion shortly before stepping out on the lunar surface during Apollo 11), and Glover said he counts himself among those who do not see science and religion as incompatible.

“If God could create the universe, God could create a thing to evolve,” Glover said, noting he once challenged a preacher’s claim that the Earth was 3,000 to 7,000 years old.

“I’m actually getting comfortable not having to answer things. You have questions? Let's talk about the question.”Victor Glover

And when the remake of the television series Cosmos aired in 2014, Glover said he had his four daughters lie down on their living room floor, close their eyes and listen as each read from the show’s description of the beginning of the universe. He asked them to build a picture in their mind of what they heard, which included descriptions of the Big Bang.

Glover encouraged his daughters to think about how someone who lived “2,000 years ago, 3,000 years ago” would describe the birth of the universe, and they noted how it echoed the Bible’s description of creation in Genesis.

“I saw my kids’ eyes light up,” Glover said. He added: “I work in science. I work in church. I don’t see them as conflicting.”



A close-up view from the Orion spacecraft during the Artemis II crew’s lunar flyby on April 6, 2026, captures a total solar eclipse, with only part of the Moon visible in the frame as it fully obscures the Sun. Venus is a bright spot on the left of the frame. (Photo courtesy of NASA)
Articulating a ‘gentle faith’

NASA also sought religious perspectives while prepping for the Artemis II mission. In a recent interview Wiseman conducted with The New Yorker, the mission commander said the agency hired “spiritual and cultural leaders” to come speak to the team “about the significance of the Moon around the world.”

NASA astronaut Victor Glover conducts leak checks on his spacesuit in the Neil A. Armstrong Operations and Checkout Building at the agency’s Kennedy Space Center on Wednesday, April 1, 2026, in Florida. (Photo courtesy of NASA/Kim Shiflett)

“We wanted to know how everyone sees the Moon,” Wiseman said.

During the mission itself, which coincided with the Christian Easter holiday and the Jewish celebration of Passover, Glover made reference to the Bible and his faith in his public statements at least twice: once during a televised interview with CBS as they hurtled away from Earth, and a second time during a broadcast just before the crew vanished behind the Moon and entered a 40-minute period of radio silence.

“As we continue to unlock the mysteries of the cosmos, I would like to remind you of one of the most important mysteries there on Earth — and that’s love,” Glover said, referencing the Gospel of Matthew during the broadcast. “Christ said, in response to what was the greatest command, that it was to love God with all that you are. And he also, being a great teacher, said this: ‘I give you equal to it, and that is to love your neighbor as yourself.’”

He added: “And so, as we prepare to go out of radio communication, we’re still able to feel your love from Earth and to all of you down there on Earth, and around the Earth, we love you from the Moon.”

It’s a kind of public-facing religious rhetoric that has proven controversial in the past. After Apollo 8 astronauts read from the book of Genesis while circling the Moon in 1968, an atheist activist filed a lawsuit. The legal challenge was thrown out, but it left NASA skittish about religious rhetoric taking center stage during missions.

But public reception of Glover’s remarks seemed generally positive, with many lauding what one commentator called the astronaut’s “gentle faith.”

“I work in science. I work in church. I don't see them as conflicting.”Victor Glover

“I tried to speak something that was true for me personally, but also true universally, no matter what you follow, whatever faith — or lack of faith — you have,” Glover said, musing that the warm reception may have been because “people’s hearts needed something,” at a time when “there’s a lot of negativity flying around.”

“You can understand how important it is to love something bigger than yourself, and how you should love your neighbor. If we could figure that out, all of us would be better today,” he said.
A religious return

According to Glover, his crewmates were frequently at a loss for words as they gazed back at an Earth that grew ever smaller throughout their journey. He often heard them exclaiming reverently to each other, “Oh my God.”

NEW: Bring more puzzles and play to your week with RNS Games

“We Christians are often, too often, quick to say, ‘do not use the Lord’s name in vain,’” he said. “I will tell you, I never felt it was in vain: I thought that is the appropriate utterance for this moment. It’s truly a God moment.”


NASA Artemis II astronauts Victor Glover, center left, and NASA astronaut Christina Koch, center right, are sit on a Navy MH-60 Seahawk on the flight deck of USS John P. Murtha after they were extracted from their Orion spacecraft after splashdown, Friday, April 10, 2026, in the Pacific Ocean off the coast of California. (Photo courtesy of NASA/Bill Ingalls)

Glover stopped short of suggesting his fellow astronauts were using the same spiritual lens he does. Neither Hansen nor Christina Koch, both mission specialists, appear to have publicly discussed their faith — if they claim one — before or after the mission, and Captain Wiseman has described himself as “not really a religious person.”

Even so, one of the first calls Wiseman made after splashing down in the Pacific Ocean on April 11 was to a chaplain. In a recent public appearance, Wiseman said that as the crew waited together in a medical bay, he felt the astronauts had “no other avenue” to “explain” what they saw during their time in space.

The Navy chaplain on duty that day was Lt. Eliseo Morales Jr., who is affiliated with the Presbyterian Church (USA). In an email to RNS, Morales said that around the same time, an officer called him and said, “Chaps, your presence is requested at medical.”

When Morales entered the room, Wiseman embraced him. The mission commander, who has discussed the encounter publicly and gave Glover permission to mention it, then broke down into tears.



“I’ve told (Wiseman) this since: That was one of the most spiritual moments of my life,” Glover said.

Morales said that he, too, left the experience moved, saying it felt “like a dream.”

“Praying for and meeting actual astronauts who we just recovered from a capsule in the middle of the ocean is a sentence I never thought I would write in my entire life,” he said in the email. “Yet God placed me on this ship for that reason.”

The impulse to call a chaplain speaks to the power religion can have in tense moments, said Glover, including when it comes to articulating the seemingly intangible.

“(Wiseman’s) brain and emotion and development and maturity thought to bring a person in who could understand,” Glover said. “When you think about it, that’s what church is supposed to be anyway: When people have need, you want them to reach for that.”

Morales felt similarly. He noted that, while his meeting with Wiseman and the other astronauts was a “once-in-a-lifetime moment,” it was “no more sacred than the time I was speaking to a young Sailor in my office … who was going through overwhelming challenges in his life.”


The Artemis II crew, from left, Mission Specialist Christina Koch, Mission Specialist Jeremy Hansen, Pilot Victor Glover, and Commander Reid Wiseman pause for a group photo inside the Orion spacecraft on their return to Earth, on April 7, 2026. (Photo courtesy of NASA)

Wiseman, in his New Yorker interview, said he and Glover discussed the divine while carving out a few hours together in the Montreal airport during a media tour in April.

“I told him, ‘I think we slipped through the hands of God during that mission,’” Wiseman said, referring to Glover. “That just stopped him in his tracks. He completely agreed. There’s just ways that we see the world right now that are totally different.”

And while a trip to the Moon and back may have left him spiritually reeling, Glover gave no indication that it fractured his faith itself. He said he initially wanted to return to church a day after coming home, and although his family shot down appearing in person, they worshipped virtually together that Sunday.

And while the Communion he shared at his “ultimate meal” was certainly uniquely timed, it was hardly his last.

“I got right back to it when I got back to Earth,” he said.



Earth is illuminated against the blackness of space in this photo taken by an Artemis II crew member through an Orion spacecraft window. (Photo courtesy of NASA)

SPACE/COSMOS

NASA head defends Artemis 3 crew of all men

AFP
June 10, 2026 

(L/R) NASA astronaut commander Randy Bresnik, ESA (European Space Agency) astronaut pilot Luca Parmitano, NASA astronaut mission specialist Frank Rubio, and NASA astronaut mission specialist Andre Douglas, the Artemis 3 crew – Copyright AFP SAUL LOEB

NASA’s administrator Jared Isaacman on Wednesday defended the makeup of the space agency’s latest Artemis crew, an all-male group.

The nominations have earned criticism that NASA may have acted in accordance with President Donald Trump’s direction to eliminate diversity and inclusion efforts.

Isaacman insisted in a lengthy social media post that the “crew selection does not involve any political appointees.”

“The Astronaut Office assigns the crew that gives the mission the best chance of meeting its objectives, taking into account many factors, including the background and expertise of the astronauts, such as test pilot experience, development work on specific programs, and availability.”

The third phase of Artemis will involve testing the Orion spacecraft and conducting rendezvous and docking tests with lunar landers. It will not include a Moon voyage.

NASA had previously committed to put both a woman and a person of color on the lunar surface.

Last year, however, NASA removed language regarding that commitment and diversity more broadly from some of its web pages, as Trump directed federal agencies to eliminate Diversity, Equity and Inclusion (DEI) programs and references.

That doesn’t necessarily mean NASA’s pledge has been scrapped, but it’s no longer explicit.

Isaacman said “those raising this concern may not be aware of the pipeline of crews,” including those “undergoing lunar-specific training that would be a better fit for a future surface mission.”

“We have an extraordinary astronaut corps, and every mission and every crew is part of a larger campaign to get America back to the Moon and to build the future we all dreamed about as children.”

The third Artemis crew includes NASA astronauts Randy Bresnik, who will serve as commander, and mission specialists Andre Douglas and Frank Rubio.

Italian astronaut Luca Parmitano will represent the European Space Agency as the voyage’s pilot, becoming the first European to join one of the program’s missions.

The crew of the Artemis 2 journey conducted this past spring was named prior to Trump’s return to the White House.

It included the first Black man, Victor Glover, and the first woman, Christina Koch, to fly around the Moon.

Jeremy Hansen became the first Canadian to carry out such a mission, while Reid Wiseman was the commander.

From Dusk Till Dawn

 June 10, 2026 

By Eurasia Review

Astronomers have revealed distinct differences in atmospheric conditions between the morning and evening transition zones of the ultra-hot gas planet WASP-121 b, which separate day from night, commonly called terminators. This achievement was only possible due to the unmatched sensitivity of the James Webb Space Telescope (JWST). Led by Cyril Gapp, a PhD student at the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany, a team of researchers detected this phenomenon, which had previously been predicted by theoretical computations.

Confirmation of variations between dusk and dawn

The discovery corresponds to an asymmetry in the absorption of infrared light received from the host star, which is partially filtered through the planet’s atmosphere during its transit. The researchers interpret this as the result of non-uniform temperatures and chemical compositions in the exoplanet’s atmosphere.

“With its unprecedented observational quality, JWST gives us the most detailed glimpses into distant planets to date: By measuring how star light absorption changes as WASP-121 b rotates, we probe its atmosphere longitude by longitude,” said Cyril Gapp, MPIA.

The data indicate that the evening terminator absorbs more light than the morning side, consistent with the commonly accepted picture of powerful winds that transport intense heat from the day to the night side. Hot winds follow the planet’s rotation eastward, which heats the evening zone. With rising temperatures, this region is bound to expand, increasing the planet’s cross-section and allowing it to absorb stellar radiation more efficiently.

Besides a general slight reduction in brightness towards the end of the transit, the data obtained by JWST’s NIRSpec (Near-infrared spectrograph) instrument also reveal an increase in the carbon monoxide (CO) signal. However, this appears to be a temperature effect, not related to an increase in carbon monoxide molecules.

In contrast, the amount of water (H2O) in the atmosphere appears to drop, which the astronomers interpret as a real decrease in water molecules. The temperatures in the upper atmosphere are high enough to break water molecules into their constituents. This result again corroborates the existence of hot winds heating the evening terminator region.

Two extreme sides of an ultra-hot planet

To detect these minute variations, the astronomers exploited a peculiar behaviour of hot gas planets. The proximity to their host stars slowly synchronizes their spin and orbital motion via tidal forces, such that eventually one rotation takes as long as one revolution. Finally, these planets exhibit two distinct hemispheres: a hot side constantly facing the star and an opposite, darker and cooler side.

“WASP-121b is particularly extreme, with average temperatures on the dayside hemisphere being around 2770 Kelvin, while those on the nightside are closer to about 1000 Kelvin,” co-author Tom Evans-Soma from the University of Newcastle, Australia, explains. He previously determined the planet’s temperature range and is also affiliated with MPIA. These values translate to almost 2500 degrees Celsius, or about 4525 degrees Fahrenheit, on the dayside, and approximately 725 degrees Celsius, or 1340 degrees Fahrenheit, at night.

When astronomers observe such a planet transiting in front of a star, the planet rotates slightly between the points of ingress and egress, revealing different fractions of its atmosphere. While the planet mostly presents its night side, our point of view permits glimpses beyond the dusk and dawn towards the bright dayside, depending on the transit’s progress. The zone leading the planet’s orbit corresponds to the morning side, and the one trailing is the evening side.

Apart from recording the measured brightness variation over time, spectrographs break light into smaller components, which physicists call a spectrum, much as a prism produces a rainbow-like distribution of colours. Since atmospheric gases absorb light at distinct colours or wavelengths, a detailed analysis reveals their chemical composition.

Elapsed time converts to longitude

Hence, the variation along the direction of rotation translates into a time-dependent change of the filtered signal. In the case of WASP-121 b, the rotation angle during a full transit amounts to about 30 degrees, which is sufficient to probe the morning (dawn) and evening (dusk) terminators with high precision in longitude.

Astronomers usually average the measurements over the entire transit to achieve a clearer signal. However, to determine how the signal changes during the planet’s trajectory across the star, Gapp and his colleagues allowed for a temporal variation while the planet rotates. By applying statistical methods, they found that their procedure provides a significantly better fit to the data, indicating that they indeed detected a significant variation.

Notable gaps in atmospheric models

To verify the measured temperatures that would cause local expansion, the astronomers ran models simulating heat distribution in the upper layers of a gas planet, depending on the planet’s properties and the constellation of the planet and its host star. While these atmospheric models confirmed the asymmetric effect caused by spatial temperature variations, the data revealed a larger signal amplitude than the models predicted.

The astronomers suspected that cooling mechanisms at the morning terminator might be at work that the models didn’t account for. Previous studies have indicated that clouds may be present, albeit composed not of water droplets but of minerals such as silicates. Clouds can efficiently shield infrared light emitted from hot gaseous layers below, mimicking lower temperatures. Infamously, simulating the physics of clouds, condensation, and evaporation in a dynamic environment is hard. Therefore, physical models commonly applied to exoplanet atmospheres, such as the one used in this study, do not account for clouds, which can yield unrealistic results.

After tweaking the simulation to approximate the effect clouds have on infrared radiation from deeper layers, the results were more consistent with observations. However, only more sophisticated models will be able to confidently confirm the presence of clouds.

A blueprint for future studies

Model updates will also improve future investigations using this method. The astronomers have already identified additional suitable targets within the required temperature range and rotation speed to successfully probe the terminator regions. This will help them establish a sample of ultrahot gas planets, revealing their longitudinal structure, and potentially discover similarities and differences among these extreme worlds.