In the high desert of Chile, under some of the clearest skies on Earth, sits one of humanity’s most powerful eyes on the cosmos: the Atacama Large Millimeter/submillimeter Array, better known as ALMA. This vast collection of 66 radio antennas works together to capture faint signals from the coldest and most hidden regions of the universe, where stars and planets are born. Now, ALMA has offered us a rare and breathtaking look at the birth of new worlds.
Astronomers studying a young star known as IM Lup, located 515 light-years away in the constellation Lupus, have captured the swirling motion of spirals in the disk of dust and gas that surrounds it. These spirals are not just beautiful—they are clues to one of the most profound processes in the universe: the formation of planets.
The Mysterious Spirals Around Young Stars
Young stars are often surrounded by protoplanetary disks, vast rings of gas and dust that orbit like cosmic construction sites. Within these disks, tiny grains collide, stick, and slowly grow into pebbles, rocks, and eventually planets. But astronomers have long sought clear signatures of when and how this transformation occurs.
Spiral patterns within these disks are among the most tantalizing clues. They resemble whirlpools in a river, winding currents in a cosmic sea. For years, scientists have debated their meaning. Do spirals signal that a planet has already formed and is carving waves in the disk? Or could the spirals themselves be part of the process that gives birth to a planet?
The case of IM Lup presented an opportunity to find out. Its disk displayed magnificent spirals, but their origin was unclear. To solve the mystery, astronomers needed not just snapshots, but time itself—a way to watch these spirals move.
A Stop-Motion Film of a Planetary Nursery
An international research team, led by Tomohiro Yoshida of SOKENDAI and the National Astronomical Observatory of Japan, turned ALMA into something like a cosmic movie camera. Over the course of seven years, ALMA observed IM Lup four times, each time recording the faint millimeter-wave glow of dust and gas in its swirling disk.
By carefully combining these observations, the researchers created a stop-motion animation of the spirals. For the first time, humanity could watch the actual motion of spiral arms around a young star, unfolding frame by frame like a slow, graceful dance.
The results were electrifying. The spirals did not move as they would if they were caused by a hidden, fully formed planet. Instead, the evidence suggested that the spirals themselves are dynamic structures that may be helping new planets take shape. The winding motion appears to concentrate dust and gas, creating fertile ground where planetary seeds can grow.
“When I saw the outcome of the analysis—the dynamic visualization of the spiral in motion—I screamed with excitement,” Yoshida recalled. His words capture the awe of witnessing something both profoundly alien and deeply connected to our own origins. After all, every planet in our solar system, including Earth, was once part of a disk like this.
Why These Findings Matter
The discovery around IM Lup is more than just a beautiful image; it is a scientific breakthrough. By revealing that spirals can be active agents of planet formation rather than mere side effects of existing planets, the findings expand our understanding of how planetary systems emerge.
This has profound implications for astronomy. If spirals are indeed fertile grounds for planet formation, then disks like IM Lup’s could be common sites of planetary birth across the galaxy. That means there may be countless stars right now whose spirals are winding up into worlds, just as our Sun once did.
The study also highlights the power of patience in science. Planetary formation unfolds over millions of years, a timescale far beyond human lifetimes. Yet by returning to IM Lup again and again, astronomers were able to compress years into moments, offering us a rare chance to see a process usually hidden from view.
A Window into Our Own Past
What makes discoveries like this so moving is their connection to our own story. Billions of years ago, before there were oceans or forests or cities, our solar system was nothing more than a young Sun wrapped in a dusty disk. Somewhere within that swirling matter, spirals may have helped gather material, nudging grains of dust into the first building blocks of Earth.
When we look at IM Lup, we are not just studying a distant star—we are glimpsing a reflection of our own beginnings. The spirals captured by ALMA are reminders that planets are not rare accidents but natural outcomes of cosmic evolution. They tell us that the conditions for creating new worlds may be written into the very fabric of star birth.
The Road Ahead: Documenting the Birth of Planetary Systems
For Yoshida and his team, IM Lup is only the beginning. They plan to use ALMA to conduct similar long-term observations of other young stars and their disks. The dream is to create not just snapshots but a full documentary of planetary systems taking shape—from the earliest spirals to the birth of planets and beyond.
ALMA, with its unmatched sensitivity and stability, is uniquely suited to this task. Its ability to track faint, cold signals over years allows astronomers to turn the invisible into the visible, revealing processes too subtle and slow for the human eye.
Each new observation brings us closer to answering the timeless question: How do worlds come into being?
A Universe Alive with Possibility
The spirals around IM Lup remind us that the universe is alive with creation. Stars are born, disks form, planets emerge, and eventually, some of those planets may harbor life. We are part of this grand cycle, made from the dust of stars and nurtured by the physics that governs their spirals.
The sight of dust swirling around a young star, captured by ALMA across years of patient observation, is not just a scientific result—it is a reminder of our place in the cosmos. Somewhere out there, countless other spirals may be winding into futures filled with new Earths, new skies, and perhaps even new beings looking up in wonder.
In the end, the story of IM Lup is also our story. It is the story of beginnings, of dust becoming worlds, of silence becoming song. And thanks to the vision of scientists and the power of telescopes like ALMA, we are privileged to witness a chapter of that story unfold, written in spirals of light across the vastness of space.
More information: Tomohiro C. Yoshida et al, Winding motion of spirals in a gravitationally unstable protoplanetary disk, Nature Astronomy (2025). DOI: 10.1038/s41550-025-02639-y
