SPACE/COSMOS
Alaknanda: JWST discovers massive grand-design spiral galaxy from the universe's infancy
Tata Institute of Fundamental Research
image:
Image of the newly discovered spiral galaxy Alaknanda (inset) as observed in the shorter wavelength JWST bands. Several bright galaxies from the foreground Abell 2744 cluster are also seen.
view moreCredit: © NASA/ESA/CSA, I. Labbe/R. Bezanson/Alyssa Pagan (STScI), Rashi Jain/Yogesh Wadadekar (NCRA-TIFR)
A spiral galaxy, shaped much like our Milky Way, has been found in an era when astronomers believed such well-formed galaxies could not yet exist. Two astronomers from India have identified a remarkably mature galaxy just 1.5 billion years after the Big Bang—a discovery that challenges our understanding of how galaxies form and evolve.
NASA's James Webb Space Telescope (JWST) is a powerful telescope capable of detecting extremely faint light from the early Universe. Using JWST, researchers Rashi Jain and Yogesh Wadadekar spotted a galaxy remarkably similar to our own Milky Way. Yet this system formed when the cosmos was barely 1.5 billion years old—roughly a tenth of its present age. They named it Alaknanda, after the Himalayan river that is a twin headstream of the Ganga alongside the Mandakini—fittingly, the Hindi name for the Milky Way.
The discovery, made at the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research (NCRA-TIFR) in Pune, India, has been published in the European journal Astronomy & Astrophysics.
Why is this surprising?
Classic spiral galaxies like ours—with two clear, symmetric arms (called a ‘grand-design’ spiral)—were thought to take billions of years to form. The prevailing view held that early galaxies should appear irregular and disordered—still in the chaotic process of assembly rather than settled into the graceful spirals we see so often in the nearby Universe. Building a grand spiral requires time: gas must flow in steadily from surrounding space (called ‘gas accretion’), settle into a rotating disk, then slow-moving waves (called ‘density waves’) may perturb the disk to sculpt the spiral arms, and the whole system needs to remain undisturbed by violent collisions with other galaxies.
Alaknanda defies these expectations. It already has two sweeping spiral arms wrapped around a bright, rounded central region (the galaxy’s ‘bulge’), spanning about 30,000 light-years across. Even more impressively, it is annually churning out new stars, their combined mass roughly equivalent to 60 times the mass of our Sun. This rate is about 20 times that of the present-day Milky Way! About half of Alaknanda’s stars appear to have formed in only 200 million years—a blink in cosmic time.
"Alaknanda has the structural maturity we associate with galaxies that are billions of years older," explains Rashi Jain, the study's lead author. "Finding such a well-organised spiral disk at this epoch tells us that the physical processes driving galaxy formation—gas accretion, disk settling, and possibly the development of spiral density waves—can operate far more efficiently than current models predict. It's forcing us to rethink our theoretical framework."
A cosmic magnifying glass
Alaknanda lies in the direction of a massive galaxy cluster called Abell 2744, also known as Pandora's Cluster. The cluster's enormous gravity bends and magnifies light from distant cosmic objects in its background, much like a magnifying glass. Called gravitational lensing, this effect made Alaknanda appear twice as bright, allowing JWST to capture its spiral structure in stunning detail.
Jain & Wadadekar analysed JWST images of the galaxy taken through as many as 21 different filters, each revealing a different part of its light. This wealth of data—part of JWST's UNCOVER and MegaScience surveys—allowed them to estimate with unusual precision the galaxy's distance, dust content, how many stars the galaxy contains, and how quickly new stars have been forming over time.
Rewriting the cosmic timeline
The discovery adds to a growing body of evidence from JWST that the early Universe was far more mature than astronomers expected. Several disk-shaped galaxies have now been found at similarly vast distances, but Alaknanda stands out as one of the clearest examples of a textbook "grand-design" spiral (a galaxy with two prominent, symmetric arms) at such an early epoch.
"Alaknanda reveals that the early Universe was capable of far more rapid galaxy assembly than we anticipated," says Yogesh Wadadekar, the study's co-author. "Somehow, this galaxy managed to pull together ten billion solar masses of stars and organise them into a beautiful spiral disk in just a few hundred million years. That's extraordinarily fast by cosmic standards, and it compels astronomers to rethink how galaxies form.”
Scientists will now debate how Alaknanda's spiral arms arose. One possibility is that the galaxy grew steadily by pulling in streams of cold gas, allowing density waves to naturally carve out spiral patterns. Another is that a gravitational encounter with a smaller companion galaxy triggered the arms—though such tidally induced spirals tend to fade quickly. Future observations with JWST's own spectroscopic instruments or the Atacama Large Millimeter Array (ALMA) telescope in Chile could measure how fast the galaxy is rotating and whether its disk is moving in an orderly way (dynamically "cold") or is more turbulent (dynamically "hot"), helping to distinguish between these scenarios.
What does this mean for us?
This discovery is more than a pretty picture from the distant past. It forces astronomers to reconsider the cosmic timeline—the story of how stars, galaxies, and ultimately planets like Earth came to be. If galaxies could mature this quickly, the early Universe was a far more dynamic and fertile place than we imagined, and the conditions for forming worlds like ours may have arisen earlier than anyone thought.
As JWST continues to peer deeper into space and time, more galaxies like Alaknanda are sure to emerge—each one a new clue to the Universe's surprisingly rapid early development.
The early Universe was far more capable of building complex and stable structures than previously believed—and Alaknanda is compelling evidence of that being the furthest disk-dominated grand-design spiral galaxy ever discovered.
Left panel: Image of Alaknanda in rest-frame near-ultraviolet filters. The star-forming regions in the spiral arms form a beads-on-a-string pattern, characteristic of UV emission from massive stars in star-forming regions. Right panel: Alaknanda as seen in rest-frame optical filters. The spiral arms are less prominent and the underlying disk is clearly seen.
Credit
© NASA/CSA/ESA, Rashi Jain (NCRA-TIFR)
Journal
Astronomy and Astrophysics
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A grand-design spiral galaxy 1.5 billion years after the Big Bang with JWST
Sun-watcher SOHO celebrates thirty years
European Space Agency
image:
The ESA/NASA Solar and Heliospheric Observatory (SOHO) has been observing the Sun for 30 years. In that time, SOHO has observed nearly three of the Sun’s 11-year solar cycles, throughout which solar activity waxes and wanes.
view moreCredit: Credit: SOHO (ESA & NASA) Acknowledgements: F. Auchère & ATG Europe
On 2 December 1995 the ESA/NASA Solar and Heliospheric Observatory (SOHO) blasted into space – on what was supposed to be a two-year mission.
From its outpost 1.5 million km away from Earth in the direction of the Sun, SOHO enjoys uninterrupted views of our star. It has provided a nearly continuous record of our Sun’s activity for close to three 11-year-long solar cycles.
"It is testament to the ingenuity of our engineers, operators and scientists, and to international collaboration, that this mission has exceeded all expectations," says Prof. Carole Mundell, ESA Director of Science. "SOHO has overcome nail-biting challenges to become one of the longest-operating space missions of all time."
"The SOHO mission is a great example of the incredible partnerships between NASA and ESA,” adds Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. "Congratulations to the NASA and ESA teams on an amazing thirty years working together."
The mission has not been without drama. Two-and-a-half years after launch, the spacecraft suffered a critical error, spinning out of control and losing contact with Earth. An international rescue team worked tirelessly for three months to locate and recover it.
Then, in November & December 1998, the spacecraft’s stabilising gyroscopes failed and a new race to save the mission began. By February 1999, new software enabled the spacecraft to fly without the need for gyroscopes, and it has been revolutionising solar science ever since.
“SOHO pioneered new fields in solar science. It is a game-changer in the study of space weather, providing real-time monitoring of the Sun to forecast potentially dangerous solar storms heading towards Earth, and its legacy continues to guide future missions,” says Daniel Müller, ESA Project Scientist for SOHO and Solar Orbiter.
“SOHO is still producing high-quality data on a daily basis, and with hundreds of papers being published every year, its scientific productivity remains very high.”
Daniel’s new paper ‘SOHO’s 30-year legacy of observing the Sun’ is published in Nature Astronomy on Tuesday 2 December 2025.
Here are five highlights from the last five years:
1. A single plasma conveyor belt
SOHO led the way in ‘helioseismology’. Akin to studying how seismic waves traverse Earth during an earthquake, helioseismology probes the inside of the Sun by studying how sound waves reverberate through it. Early in its career, SOHO provided the first images of plasma flows (electrically charged material) beneath the Sun’s surface, offering a unique window into its layered interior.
Thanks to SOHO’s long lifetime, scientists have used helioseismology to solve an enduring mystery: plasma flows along a single loop, or cell, in each of the Sun's hemispheres – not multiple cells as previously thought.
The data show that it takes about 22 years for plasma to complete an entire loop around this single ‘conveyor belt’, flowing from the surface near the equator up to the poles, then traveling back down deep inside towards the equator. This matches the timeline of the Sun’s magnetic cycle, explaining how sunspots – regions where intense magnetic fields break through the Sun’s surface – emerge progressively closer to the equator over the solar cycle.
[https://www.esa.int/ESA_Multimedia/Images/2015/12/The_anatomy_of_our_Sun ]
2. Does the Sun shine steadily?
The amount of energy that floods out of the Sun is a fundamental quantity in understanding the impact of solar heating on Earth’s atmosphere and climate. SOHO’s three decades of data, in combination with older measurements, provide unrivalled measurements spanning nearly fifty years.
The total energy output of the Sun changes very little – on average, by only 0.06% over the solar cycle. By contrast, the variation in extreme ultraviolet radiation is substantial, doubling between solar minimum and maximum. Solar extreme ultraviolet radiation significantly influences the temperature and chemistry in Earth’s upper atmosphere, but is not a direct driver of the global warming trends observed near Earth’s surface.
3. Solar storm monitoring made law
SOHO has played such a pivotal role in the development of real-time space weather monitoring systems that it was signed into United States law in October 2020.
The ‘Promoting Research and Observations of Space Weather to Improve the Forecasting of Tomorrow’ (PROSWIFT) act specifically mentions SOHO's Large Angle and Spectrometric Coronagraph (LASCO) instrument.
LASCO is a coronagraph, a telescope with a disc masking the centre of view. By blocking out the direct light coming from the Sun, the instrument can see light from the surrounding atmosphere, called the corona. This allows us to see coronal mass ejections – large eruptions of solar material and magnetic fields – as they set off from the Sun, providing up to three days warning of potentially disruptive incoming space weather reaching Earth.
[https://www.esa.int/ESA_Multimedia/Images/2023/08/Coronal_mass_ejection_on_28_October_2021 ]
4. 5000 comets – and counting!
The telescope’s prowess as a comet hunter was unplanned, but turned out to be an unexpected success. Thanks to the screening effect of SOHO’s coronagraph, ‘sungrazer’ comets – those that approach the Sun at very close distances – also become visible.
Not all comets seen by SOHO are sungrazers. For example, it also beautifully captured Comet Tsuchinshan–ATLAS, also called the Great Comet of 2024, a non-periodic comet from the outer reaches of the Solar System.
SOHO discovered its 5000th comet in March 2024, making it the most prolific comet-discoverer in history. Most of these have been found by citizen scientists worldwide through the Sungrazer Project. The observations have provided valuable data on the movement, composition and dust production of comets.
5. Enabling future discoveries
SOHO’s success has shaped the next generation of solar observatories, both in terms of their technology and scientific objectives, as well as being a role model for open data policies and international collaboration.
For example, the ESA-led Solar Orbiter mission is imaging the solar poles from higher latitude and flying much closer to the Sun, with many of its instruments being successors of SOHO's. Similarly, NASA’s Solar Dynamics Observatory carries improved versions of SOHO’s instruments to continue the legacy that SOHO began in areas of full-disc imaging and helioseismology. Moreover, SOHO frequently contributes to ‘multipoint’ measurements, providing essential context for Solar Orbiter and NASA’s Parker Solar Probe as they fly along their own unique orbits around the Sun.
Even more recently, ESA’s Proba-3 took to the skies to open up new views of the Sun’s faint corona, while the Agency’s upcoming Vigil mission will be the first to monitor the Sun from the ‘side’, detecting solar storms before they roll into SOHO’s line-of-sight.
“SOHO is an all-round shining success, thanks to the dedication of the teams keeping this incredible machine flying,” says Daniel. “Its science remains valuable and relevant, serving generations of scientists, and I’m certain that its legacy will continue to guide solar science for decades to come.”
Launched on 2 December 1995, the ESA/NASA Solar and Heliospheric Observatory (SOHO) has been observing the Sun for 30 years. This graphic highlights some of the mission’s impressive numbers to date, which will continue to increase over the coming years.
[Image description: Infographic showing cartoon icons and related numbers. In the centre, an image of the Sun has ‘30 years’ written inside it and the SOHO spacecraft partially overlapping its left side. Clockwise from the top, the graphic lists: 3 solar cycles, 24 million images, 300 PhD theses, 7000 papers published, 60 TB data in the SOHO archive, 2.8 million command blocks sent, 18 years on ground stations, 5000 comets and 40 000 coronal mass ejections. The bottom right of the graphic adds a note ‘...and counting’.]
Credit
Credit: SOHO (ESA & NASA) Acknowledgements: ATG Europe
Journal
Nature Astronomy
Article Title
SOHO’s 30-year legacy of observing the Sun
Article Publication Date
2-Dec-2025
Dynamic duo of bacteria could change Mars dust into versatile building material for first human colonists
Frontiers
Humanity had a dream: the alien world we hope to call home
Since humanity’s first steps on the Moon, the aspiration to extend human civilization beyond Earth has been a central objective of international space agencies, targeting long-term extraterrestrial habitation. Among the celestial bodies within our reach, Mars is considered our next home. The Red Planet, with its stark landscapes and tantalizing similarities to Earth, beckons as the frontier of human exploration and settlement. But establishing a permanent foothold on Mars remains one of humanity’s boldest dreams and the most formidable scientific and engineering challenge.
The Red Planet, once draped in a thick atmosphere, has undergone dramatic transformation over billions of years. Its protective blanket vanished, leaving behind an environment nearly unrecognizable to terrestrial life. Today, its air is whisper-thin and rich in carbon dioxide, pressure is less than one percent of Earth’s, and temperatures swing wildly from a freezing –90°C to a mild 26°C. Add to this constant cosmic radiation and the absence of breathable air, and it becomes clear: creating shelter on Mars is about much more than building walls. It’s about crafting a life-supporting sanctuary that stands strong against an alien world. Transporting building materials from Earth is prohibitively expensive and impractical. The solution? Learning to build using what Mars itself offers. In situ resource utilization (ISRU), harnessing local materials, is the key to unlocking sustainable human presence on Mars.
As samples gathered by NASA’s Perseverance rover from Jezero Crater, an ancient Martian riverbed, may hold traces of primordial life, it invites us to dream beyond discovery. Could the same microbial fingerprints that once thrived on Mars also help us build on it?
From Earth to Mars
Once upon a time, life on Earth began with humble microorganisms in shallow pools and seas. These silent engineers transformed our planet, from filling the skies with oxygen to building resilient coral reefs that stand to this day. Now, as humanity’s gaze shifts skyward, these tiny creators may hold the key to turning a barren world into a vibrant home.
Our research pioneers a bold path, drawing inspiration from Mother Nature. In an internationally cross-disciplinary effort, we came together to harness a natural wonder: biomineralization. This phenomenon, which unfolds when microorganisms (bacteria, fungi, and microalgae) produce minerals as part of their metabolism, has shaped Earth’s landscapes for billions of years. These microorganisms that thrive not only in familiar waters but also in extreme environments like acidic lakes, volcanic soils, and deep caves may reveal the versatility needed for Martian adaptation.
Guided by data from Mars rovers regarding the Martian soil (regolith) composition, our research explores multiple microbial mineralization pathways to discover which can forge strong building materials for Mars habitats without posing an interplanetary pollution risk. Among them, biocementation, which uses microorganisms to generate natural cement-like materials like calcium carbonate at room temperature, shines as the most promising. At the core of our research is a collaborative effort between two remarkable bacteria: Sporosarcina pasteurii, a well-known bacterium that produces calcium carbonate via ureolysis, and Chroococcidiopsis, a resilient cyanobacterium known for surviving extreme environments, including simulated Martian conditions. Together, they form a powerful partnership. Chroococcidiopsis breathes life into its surroundings by releasing oxygen, creating a welcoming microenvironment for Sporosarcina pasteurii. Moreover, the extracellular polymeric substance secreted by Chroococcidiopsis shields Sporosarcina pasteurii from harmful UV radiation on the Martian surface. In turn, Sporosarcina secretes natural polymers that nurture mineral growth and strengthen regolith, turning loose soil into solid, concrete-like material.
We envision this bacterial co-culture mixed with Martian regolith as feedstock for 3D printing on Mars. At the intersection of astrobiology, geochemistry, material science, construction engineering, and robotics, this synergistic system could revolutionize the potential for construction on the Red Planet, redefining the design-for-manufacturing on Mars.
But this microbial partnership offers benefits beyond construction. Chroococcidiopsis, with its ability to produce oxygen, could support not just habitat integrity but also the life-support systems for astronauts. Over longer timescales, the ammonia produced as a metabolic byproduct of Sporosarcina pasteurii might be used to develop closed-loop agricultural systems and potentially help in Mars's terraforming efforts.
One step at a time
Yet the journey is just beginning. Although international agencies plan to build the first human habitat on Mars in the 2040s, the Mars sample return is facing recurring delays, constraining experimental validation of Mars-specific construction technologies. As space agencies prepare for crewed Mars missions in the coming decade, we must advance our understanding of bio-derived extraterrestrial construction to be ready for the day to come.
From an astrobiology perspective, we must unravel how these microbial communities interact with Martian regolith and survive stressors from the planet’s hostile environment. Laboratory regolith simulants offer a pragmatic approach to testing co-cultures in conditions that echo those on Mars and to building predictive models for biocementation performance. On the robotics front, one major challenge is replicating Martian gravity on Earth to test 3D printing processes and optimize autonomous construction control for future Mars missions. Therefore, we must develop robust control algorithms and tailored protocols that will enable us not only to build more efficiently but also to redefine manufacturing methods for Mars’s unique environment. The journey is vigorous, but step by step, every discovery, each successful trial and tested protocol, brings us closer to the day when humanity will call Mars our home.
Journal
Frontiers in Microbiology
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
From Earth to Mars: A Perspective on Exploiting Biomineralization for Martian Construction
Article Publication Date
2-Dec-2025
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