Using NASA’s James Webb Space Telescope, astronomers have spotted two rare kinds of dust in the dwarf galaxy Sextans A, one of the most chemically primitive galaxies near the Milky Way. The finding of metallic iron dust and silicon carbide (SiC) produced by aging stars, along with tiny clumps of carbon-based molecules, shows that even when the universe had only a fraction of today’s heavy elements, stars and the interstellar medium could still forge solid dust grains. This research with Webb is reshaping ideas about how early galaxies evolved and developed the building blocks for planets, as NASA explores the secrets of the universe and our place in it.

Sextans A lies about 4 million light-years away and contains only 3 to 7 percent of the Sun’s metal content, or metallicity, the astrophysical term for elements heavier than hydrogen and helium. Because the galaxy is so small, unlike other nearby galaxies, its gravitational pull is too weak to retain the heavy elements like iron and oxygen created by supernovae and aging stars.

Galaxies like it resemble those that filled the early universe just after the big bang, when the universe was made of mostly hydrogen and helium, before stars had time to enrich space with ‘metals.’ Because it is relatively close, Sextans A gives astronomers a rare chance to study individual stars and interstellar clouds under conditions similar to those shortly after the big bang.

“Sextans A is giving us a blueprint for the first dusty galaxies,” said Elizabeth Tarantino, postdoctoral researcher at the Space Telescope Science Institute and lead author of the results in one of the two studies presented at a press conference at the 247th meeting of the American Astronomical Society in Phoenix. “These results help us interpret the most distant galaxies imaged by Webb and understand what the universe was building with its earliest ingredients.”

Image A: Sextans A PAHs Pull-out (NIRCam and MIRI Image)

Forging dust without usual ingredients

One of those studies, published in the Astrophysical Journal, honed in on a half a dozen stars with the low-resolution spectrometer aboard Webb’s MIRI (Mid-Infrared Instrument). The data collected shows the chemical fingerprints of the bloated stars very late in their evolution, called asymptotic giant branch (AGB) stars. Stars with masses between one and eight times that of the Sun pass through this phase.

“One of these stars is on the high-mass end of the AGB range, and stars like this usually produce silicate dust. However, at such low metallicity, we expect these stars to be nearly dust-free,” said Martha Boyer, associate astronomer at the Space Telescope Science Institute and lead author in that second companion study. “Instead, Webb revealed a star forging dust grains made almost entirely of iron. This is something we’ve never seen in stars that are analogs of stars in the early universe.”

Silicates, the usual dust formed by oxygen-rich stars, require elements like silicon and magnesium that are almost nonexistent in Sextans A. It would be like trying to bake cookies in a kitchen without flour, sugar, and butter. 

A normal cosmic kitchen, like the Milky Way, has those crucial ingredients in the form of silicon, carbon, and iron. In a primitive kitchen, like Sextans A, where almost all of those ingredients are missing, you barely have any proverbial flour or sugar. Therefore, astronomers expected that without those key ingredients, stars in Sextans A couldn’t “bake” much dust at all. 

However, not only did they find dust, but Webb showed that one of these stars used an entirely different recipe than usual to make that dust. 

The iron-only dust, as well as silicon carbide produced by the less massive AGB stars despite the galaxy’s low silicon abundance, proves that evolved stars can still build solid material even when the typical ingredients are missing. 

“Dust in the early universe may have looked very different from the silicate grains we see today,” Boyer said. “These iron grains absorb light efficiently but leave no sharp spectral fingerprints and can contribute to the large dust reservoirs seen in far-away galaxies detected by Webb.”

Image B: Sextans A Context Image (Webb and KPNO)

Tiny clumps of organic molecules

In the companion study, currently under peer review, Webb imaged Sextans A’s interstellar medium and discovered polycyclic aromatic hydrocarbons (PAHs), which are complex, carbon-based molecules and the smallest dust grains that glow in infrared light. The discovery means Sextans A is now the lowest-metallicity galaxy ever found to contain PAHs.

But, unlike the broad, sweeping PAH emission seen in metal-rich galaxies, Webb revealed PAHs in tiny, dense pockets only a few light-years across.

“Webb shows that PAHs can form and survive even in the most metal-starved galaxies, but only in small, protected islands of dense gas,” said Tarantino. 

The clumps likely represent regions where dust shielding and gas density reach just high enough to allow PAHs to form and grow, solving a decades-long mystery about why PAHs seem to vanish in metal-poor galaxies.

The team has an approved Webb Cycle 4 program to use high-resolution spectroscopy to study the detailed chemistry of Sextans A’s PAH clumps further. 

Image C: Giant Star in Dwarf Galaxy Sextans A (Spectrum)

Connecting two discoveries

Together, the results show that the early universe had more diverse dust production pathways than the more established and proven methods, like supernova explosions. Additionally, researchers now know there’s more dust than predicted at extremely low metallicities. 

“Every discovery in Sextans A reminds us that the early universe was more inventive than we imagined,” said Boyer. “Clearly stars found a way to make the building blocks of planets long before galaxies like our own existed.”

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

To learn more about Webb, visit:

https://science.nasa.gov/webb

Downloads & Related Information

The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and spanish translation links.

Related Links

Read more: Webb Science: Galaxies Through Time

Explore more: Massive stars: Engines of Creation

Explore more: Wolf-Rayet Apep Visualization

Read more: Spectroscopy 101

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Webb Mission Page

Related for Kids

What is the Webb Telescope?

SpacePlace for Kids

After combing through NASA’s James Webb Space Telescope’s archive of sweeping extragalactic cosmic fields, a small team of astronomers at the University of Missouri says they have identified a sample of galaxies that have a previously unseen combination of features. Principal investigator Haojing Yan compares the discovery to an infamous oddball in another branch of science: biology’s taxonomy-defying platypus.

“It seems that we’ve identified a population of galaxies that we can’t categorize, they are so odd. On the one hand they are extremely tiny and compact, like a point source, yet we do not see the characteristics of a quasar, an active supermassive black hole, which is what most distant point sources are,” said Yan.

The research was presented in a press conference at the 247th meeting of the American Astronomical Society in Phoenix. 

Image A: Galaxies in CEERS Field (NIRCam image)

“I looked at these characteristics and thought, this is like looking at a platypus. You think that these things should not exist together, but there it is right in front of you, and it’s undeniable,” Yan said.

The team whittled down a sample of 2,000 sources across several Webb surveys to identify nine point-like sources that existed 12 to 12.6 billion years ago (compared to the universe’s age of 13.8 billion years). Spectral data gives astronomers more information than they can get from an image alone, and for these nine sources it doesn’t fit existing definitions. They are too far away to be stars in our own galaxy, and too faint to be quasars, which are so brilliant that they outshine their host galaxies. Though the spectra resemble the less distant “green pea” galaxies discovered in 2009, the galaxies in this sample are much more compact.

“Like spectra, the detailed genetic code of a platypus provides additional information that shows just how unusual the animal is, sharing genetic features with birds, reptiles, and mammals,” said Yan. “Together, Webb’s imaging and spectra are telling us that these galaxies have an unexpected combination of features.”

Yan explained that for typical quasars, the peaks in their characteristic spectral emission lines look like hills, with a broad base, indicating the high velocity of gas swirling around their supermassive black hole. Instead, the peaks for the “platypus population” are narrow and sharp, indicating slower gas movement. 

While there are narrow-line galaxies that host active supermassive black holes, they do not have the point-like feature of the sample Yan’s team has identified.

Image B: Galaxy CEERS 4233-42232: Comparison With Quasar Spectrum

Has Yan’s team discovered a missing link in the cosmos? Once the team determined that the objects didn’t fit the definition of a quasar, graduate student researcher Bangzheng Sun analyzed the data to see if there were signatures of star-forming galaxies.

“From the low-resolution spectra we have, we can’t rule out the possibility that these nine objects are star-forming galaxies. That data fits,” said Sun. “The strange thing in that case is that the galaxies are so tiny and compact, even though Webb has the resolving power to show us a lot of detail at this distance.”

One proposal the team suggests is that Webb, as promised, is revealing earlier stages of galaxy formation and evolution than we have ever been able to see before. It is generally accepted across the astronomy community that large, massive galaxies like our own Milky Way grew by many smaller galaxies merging together. But, Yan asks, what comes before small galaxies? 

“I think this new research is presenting us with the question, how does the process of galaxy formation first begin? Can such small, building-block galaxies be formed in a quiet way, before chaotic mergers begin, as their point-like appearance suggests?” Yan said.

To begin answering that question, as well as to determine more about the nature of their odd platypuses, the team says they need a much larger sample than nine to analyze, and with higher-resolution spectra. 

“We cast a wide net, and we found a few examples of something incredible. These nine objects weren’t the focus; they were just in the background of broad Webb surveys,” said Yan. “Now it’s time to think about the implications of that, and how we can use Webb’s capabilities to learn more.”

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

To learn more about Webb, visit:

https://science.nasa.gov/webb

Downloads & Related Information

The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and spanish translation links.

Related Links

Read more: Webb Science: Galaxies Through Time

Explore more: ViewSpace Seeing Farther: Hubble Ultra Deep Field

Explore more: JWST’s Tiny Red Sources and the Big Questions They Raise

Read more: Webb Shows Many Early Galaxies Looked Like Pool Noodles, Surfboards

More Webb News

More Webb Images

Webb Science Themes

Webb Mission Page

Related for Kids

What is the Webb Telescope?

SpacePlace for Kids

In southwestern Angola, an expanse of coastal plains comes to an abrupt end at a natural barrier. The Huíla plateau soars above the lowlands to elevations of around 2,300 meters (7,500 feet). The sharp transition results in dramatic landscapes and a sudden change from an arid environment to more-temperate climes.  

The serrated edge of the Huíla plateau zigzags through this image, which is a mosaic of scenes acquired on June 19 and 20, 2025, with the OLI-2 (Operational Land Imager-2) and OLI on the Landsat 9 and Landsat 8 satellites, respectively. Areas around the plateau’s edges appear green with vegetation. But the landscape tends to look much browner by late September, at the end of the region’s dry season, during which almost no rain falls.  

This topography is part of the Great Escarpment of southern Africa, a 5,000-kilometer-long feature running roughly parallel to the continent’s edge. From Angola, it extends south through Namibia, across South Africa, and then northeast into Zimbabwe and Mozambique. The image below, acquired with the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite, shows a longer segment of the escarpment in Angola.  

Scientists believe the escarpment formed after the breakup of the supercontinent Gondwana in the Jurassic period. Since then, erosion has worn away at the continental margin such that the escarpment now sits 50 to 200 kilometers (30 to 120 miles) back from the coast.   

This Angolan section of the escarpment features dizzying, yet beautiful, landscapes. Tundavala Gap, a gouge eroded into the cliff line (below), is one of the most iconic with its well-framed view of the plains below. The precipice also presents a substantial obstacle to transportation. A stretch of the Namibe-Lubango Road overcomes this challenge with a series of scenic hairpin turns climbing to Serra da Leba pass near the town of Leba.  

Lubango, one of Angola’s largest cities, occupies a valley on the Huíla plateau. In addition to its remarkable natural surroundings, the city boasts a diverse mix of cultures, striking architecture, and a wide variety of locally produced foods.  

NASA Earth Observatory images by Wanmei Liang, using Landsat data from the U.S. Geological Survey, and VIIRS data from NASA EOSDIS LANCE, GIBS/Worldview, the Suomi National Polar-orbiting Partnership, and the Joint Polar Satellite System (JPSS). Photo of Tundavala Gap © jbdodane.com. Story by Lindsey Doermann. 

References & Resources 

• African Leadership Magazine (2024, May 3) Unveiling Lubango, the Hidden Gem of Southern Angola. Accessed January 5, 2026. 
• The American Alpine Journal (2024) Fenda da Tundavala and Serra da Leba, New Routes. Accessed January 5, 2026. 
• Atlas Obscura (2025, August 18) Serra da Leba Pass. Accessed January 5, 2026. 
• Clark, V.R., et al. (2011) The Great Escarpment of southern Africa: a new frontier for biodiversity exploration. Biodiversity and Conservation, 20, 2543–2561. 
• CNN (2023, November 27) Lubango: The spectacular African destination you’ve probably never heard of. Accessed January 5, 2026.
• NASA Earth Observatory (2017, March 13) South Africa’s “Brown Gold.” Accessed January 5, 2026. 
• NASA Earth Observatory (2013, December 14) South Africa Tribute. Accessed January 5, 2026.

By Michael Allen 
 
For the first time, scientists have used NASA’s IXPE (Imaging X-ray Polarization Explorer) to study a white dwarf star. Using IXPE’s unique X-ray polarization capability, astronomers examined a star called the intermediate polar EX Hydrae, unlocking the geometry of energetic binary systems. 
 
In 2024, IXPE spent nearly one week focused on EX Hydrae, a white dwarf star system located in the constellation Hydra, approximately 200 light-years from Earth. A paper about the results published in the Astrophysical Journal. Astrophysics research scientists based at the Massachusetts Institute of Technology in Cambridge led the study, along with co-authors at the University of Iowa, East Tennessee State University, University of Liége, and Embry Riddle Aeronautical University. 
 
A white dwarf star occurs after a star runs out of hydrogen fuel to fuse in its core but is not massive enough to explode as core-collapse supernovae. What remains is very dense, roughly the same diameter as Earth with as much mass as our Sun.  
 
EX Hydrae is in a binary system with a main sequence companion star, from which gas is continuously falling onto the white dwarf. How exactly the white dwarf is accumulating, or accreting, this matter and where it arrives on the white dwarf depends on the strength of the white dwarf star’s magnetic field. 
 
In the case of EX Hydrae, its magnetic field is not strong enough to focus matter completely at the star’s poles. But, it is still rapidly adding mass to the accretion disk, earning the classification “intermediate polars. 

In an intermediate polar system, material forms an accretion disk while also being pulled towards its magnetic poles. During this phenomenon, matter reaches tens of millions of degrees Fahrenheit, bouncing off other material bound to the white dwarf star, creating large columns of gas that emit high-energy X-rays – a cosmic situation perfect for IXPE to study.

“NASA IXPE’s one-of-a-kind polarimetry capability allowed us to measure the height of the accreting column from the white dwarf star to be almost 2,000 miles high – without as many assumptions required as past calculations,” said Sean Gunderson, MIT scientist and lead author on the paper. “The X-rays we observed likely scattered off the white dwarf’s surface itself. These features are far smaller than we could hope to image directly and clearly show the power of polarimetry to ‘see’ these sources in detail never before possible.”

Information from IXPE’s polarization data of EX Hydrae will help scientists understand other highly energetic binary systems.

More about IXPE 

 The IXPE mission, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. It is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, Inc., headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder. Learn more about IXPE’s ongoing mission here: 

https://www.nasa.gov/ixpe

NASA announced Monday the selection of industry proposals to advance technologies for the agency’s Habitable Worlds Observatory concept – the first mission that would directly image Earth-like planets around stars like our Sun and study the chemical composition of their atmospheres for signs of life. This flagship space telescope also would enable wide-ranging studies of our universe and support future human exploration of Mars, our solar system, and beyond.

“The Habitable Worlds Observatory is exactly the kind of bold, forward-leaning science that only NASA can undertake,” said NASA Administrator Jared Isaacman. “Humanity is waiting for the breakthroughs this mission is capable of achieving and the questions it could help us answer about life in the universe. We intend to move with urgency, and expedite timelines to the greatest extent possible to bring these discoveries to the world.”

To achieve its science goals, the Habitable Worlds Observatory would need a stable optical system that moves no more than the width of an atom while it conducts observations. The mission also would require a coronagraph – an instrument that blocks the light of a star to better see its orbiting planets – thousands of times more capable than any space coronagraph ever built. The Habitable Worlds Observatory would be designed to allow servicing in space, to extend its lifetime and bolster its science over time.

To further the readiness of these technologies, NASA has selected proposals for three-year, fixed-price contracts from the following companies:

• Astroscale U.S. Inc., Denver
• BAE Systems Space and Mission Systems, Inc., Boulder, Colorado
• Busek Co. Inc, Natick, Massachusetts
• L3Harris Technologies Inc., Rochester, New York
• Lockheed Martin Inc., Palo Alto, California
• Northrop Grumman Inc., Redondo Beach, California
• Zecoat Co. Inc., Granite City, Illinois

“Are we alone in the universe? is an audacious question to answer, but one that our nation is poised to pursue, leveraging the groundwork we’ve laid from previous NASA flagship missions. With the Habitable Worlds Observatory, NASA will chart new frontiers for humanity’s exploration of the cosmos,” said Shawn Domagal-Goldman, director of the Astrophysics Division at NASA Headquarters in Washington. “Awards like these are a critical component of our incubator program for future missions, which combines government leadership with commercial innovation to make what is impossible today rapidly implementable in the future.”

The newly selected proposals build on previous industry involvement, which began in 2017 under NASA’s “System-Level Segmented Telescope Design” solicitations and continued with awards for large space telescope technologies in 2024. The newly selected proposals will help inform NASA’s approach to planning for the Habitable Worlds Observatory concept, as the agency builds on technologies and lessons learned from its Hubble Space Telescope, James Webb Space Telescope, and upcoming Nancy Grace Roman Space Telescope.

To learn more about NASA’s Habitable Worlds Observatory, visit:

https://nasa.gov/hwo

-end-

Alise Fisher
Headquarters, Washington
202-358-2546
alise.m.fisher@nasa.gov

Jupiter beams bright, Saturn and the Moon cozy up, and the Beehive Cluster appears

Jupiter is at its biggest and brightest all year, the Moon and Saturn pair up, and the Beehive Cluster buzzes into view.

Skywatching Highlights

• Jan. 10: Jupiter at opposition
• Jan. 23: Saturn and Moon conjunction
• Jan. (throughout): Beehive Cluster

Transcript

Jupiter is at its biggest and brightest

The Moon and Saturn share the sky 

And the beehive cluster makes an appearance 

That’s what’s up, this January

January 10, Jupiter will be at its most brilliant of the entire year! 

This night, Jupiter will be at what’s called “opposition,” meaning that Earth will be directly between Jupiter and the Sun. 

In this alignment, Jupiter will appear bigger and brighter in the night sky than it will all year – talk about starting off the new year bright! 

To see Jupiter at its best this year, look to the east and all evening long, you’ll be able to see the planet in the constellation Gemini. It will be one of the brightest objects in the night sky (only the moon and Venus will be brighter)  

Saturn and the Moon will share the sky on January 23rd as part of a conjunction!  

A conjunction is when objects in the sky look close together even though they’re actually far apart. 

To spot the pair, look to the west and you’ll see Saturn just below the moon, sparkling in the night sky. 

The beehive cluster will be visible in the night sky throughout January!

The beehive cluster, more formally known as Messier 44, or M44, is made of at least 1,000 stars

It’s an open star cluster, meaning it’s a loosely-bound group of stars. There are thousands of open star clusters like the beehive in the Milky Way Galaxy! 

To see the beehive cluster, look to the eastern night sky after sunset and before midnight throughout the month – especially great nights to spot the cluster are around the middle of January when the cluster isn’t too high or low in the sky to see.   

With dark skies you might be able to spot the beehive with just your eyes, but binoculars or a small telescope will help. 

Here are the phases of the Moon for January.

You can stay up to date on all of NASA’s missions exploring the solar system and beyond at science.nasa.gov.

I’m Chelsea Gohd from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.

Listen to this audio excerpt from Jacki Mahaffey, Artemis II chief training officer:

When the Artemis II crew travels around the Moon aboard the Orion spacecraft, they will have spent countless hours training for their lunar mission, and Jacki Mahaffey will have played a role in preparing them for their journey.

As the Artemis II chief training officer at NASA’s Johnson Space Center in Houston, Mahaffey manages the planning, development, and implementation of the astronauts’ training and integrated simulations. Her job is to ensure that when the Artemis II crew travels around the Moon inside Orion, the astronauts and flight controllers are ready for every moment — expected and unexpected.

The Artemis II crew began their rigorous training in 2023, but the work of Mahaffey and her team started long before that. Years before the training began, her team gathered the experts on how to operate the different aspects of Orion, and what the crew will need to know to execute their mission.

“One of my favorite moments from that process was when we all got together in one room, and everyone brought a piece of paper for every single lesson or training event that they expected to do with the crew,” Mahaffey said. “And we laid the entire thing out to figure out what’s the most logical order to put all of this training in, to help build that big picture for the crew.”

Training for Artemis II began shortly after the crew was announced, with Mahaffey and her team introducing the astronauts to Orion’s systems and operational basics. Once the necessary simulators and mockups were ready, the crew transitioned into hands-on training to build familiarity with their spacecraft.

At Johnson, Mahaffey’s team utilizes a range of specialized facilities, including the Space Vehicle Mockup Facility, where astronauts rehearse living and working inside the Orion mockup; the Orion Mission Simulator, which replicates flight software and displays; and the Neutral Buoyancy Laboratory, where the crew practices water survival techniques for post-splashdown scenarios.

“We try to simulate as much as we can here on Earth,” said Mahaffey. “But we still have gravity, so we rely on the crew’s experience to imagine how they’ll use the space in microgravity”

Three of the four Artemis II astronauts have flown in space before, and Mahaffey sees their experience as a powerful asset. They bring insights that shape procedures and training plans, and they learn from each other’s unique problem-solving styles.

“They are teaching us back about how to have that crew perspective of working in space and the things that are going to matter most,” she said.

Mahaffey’s journey began with a love for engineering and a role as a flight controller in Johnson’s Mission Control Center. She found joy in training others and eventually transitioned into a full-time training role. Now, she leads a team of about 100 contributors, all working to prepare the crew for their historic mission.

“I didn’t start out wanting to be a trainer — I studied engineering because I loved physics and math,” she said. “But as the job shifted toward applying that engineering knowledge, communicating, and planning how to operate a spacecraft, the natural next step was teaching others.”

For Mahaffey, Artemis is a bridge connecting her family’s legacy with the future of space exploration. Her grandfather worked on control systems for Apollo, and she sees her work as a continuation of that story, now with more advanced technology and new frontiers. 

“We’re doing some of the same things Apollo did, but expanding on them,” she said. “We’re learning more about the Moon, our Earth’s history, and how we’ll get to Mars.” 

Her role during Artemis II also includes serving as an Artemis capcom, short for capsule communicator, the position in mission control that directly communicates with the crew members. Mahaffey plans to work the entry shift for Artemis II — helping to guide the crew to splashdown and ensuring their safe recovery. The moment will be a culmination of her entire team’s hard work. 

“I’ll feel good when the recovery forces report that the hatch is open,” Mahaffey said. “That moment will be incredible.”