Each tool sees the universe differently, compensating for the others.
Twenty-four million light-years from Earth, in the southern constellation Grus, a barred spiral galaxy called NGC 7496 has been brought into careful focus by the Hubble Space Telescope. Released in May 2022, the image is less a portrait than a question — how do stars come to be? — answered through the combined sight of orbiting cameras and ground-based radio arrays. The effort belongs to a longer human story: one generation of astronomers building instruments, the next using them to prepare the way for instruments not yet imagined.
- Hubble trained two of its most powerful cameras on NGC 7496, but the real urgency lay not in the image itself — it lay in what the image was meant to unlock about the origins of stars.
- No single telescope could see the full picture: Hubble captured light, while ALMA detected the cold gas clouds where stars are quietly being born, and only together did the two reveal what neither could alone.
- The combined dataset is already in motion toward a larger purpose — feeding the groundwork for the James Webb Space Telescope, which launched in December 2021 and was weeks away from beginning full science operations.
- What is taking shape is a relay race across generations of instruments: Hubble's decades of visible-light observation, ALMA's radio sensitivity, and Webb's coming ability to pierce through dust entirely with infrared vision.
- The image of NGC 7496 lands not as a conclusion but as a handoff — a moment where one era of astronomy deliberately prepares the next to see further and more clearly than ever before.
Twenty-four million light-years away, in the constellation Grus — one of four Southern Birds in the night sky — sits a barred spiral galaxy called NGC 7496. In May 2022, the Hubble Space Telescope released a detailed image of it, the product of a deliberate effort to understand how stars are born.
Hubble did not work alone. Astronomers paired its Wide Field Camera 3 and Advanced Camera for Surveys with data from ALMA, the powerful Chilean radio telescope array. The pairing was intentional: by observing NGC 7496 across different wavelengths, researchers could trace the relationship between newly formed stars and the cold, dense gas clouds that give rise to them — details no single instrument could reveal on its own.
The timing carried its own significance. The James Webb Space Telescope had launched just months earlier in December 2021, and by summer 2022 it would begin science operations. The observations of NGC 7496 were being gathered not only for their own sake, but as groundwork — a foundation of knowledge designed to make Webb's future observations more meaningful.
Each instrument sees the universe differently. Hubble captures visible and ultraviolet light. ALMA detects the faint radiation of cold gas and dust. Webb, when fully operational, would see deeper still into the infrared, piercing through the very dust clouds that block all other views. Together, they form a layered, multi-spectrum vision of the cosmos.
For the casual observer, the image is simply striking — a spiral galaxy rendered in fine detail, its arms traced in light. For the astronomer, it is something more: evidence of how the universe builds itself, star by star, and proof that the most powerful questions are answered not by one instrument, but by many generations working in concert.
Twenty-four million light-years away, in a corner of the sky marked by bird constellations, sits a galaxy that has just come into focus. The Hubble Space Telescope, a joint project of NASA and the European Space Agency, has trained its instruments on NGC 7496—a barred spiral galaxy in the constellation Grus, one of four Southern Birds that dot the night sky alongside the peacock, phoenix, and toucan. The image, released in May 2022, represents something more than a pretty picture. It is the product of a deliberate scientific effort to understand how stars are born.
The photograph itself was made using two of Hubble's most capable tools: the Wide Field Camera 3 and the Advanced Camera for Surveys. But Hubble did not work alone. Astronomers combined its observations with data from ALMA, the Atacama Large Millimeter/submillimeter Array, one of the world's most powerful radio telescopes. This pairing was intentional. The research team was investigating the relationship between young, newly formed stars and the cold, dense clouds of gas that serve as their birthplaces. By looking at NGC 7496 through multiple instruments and across different wavelengths of light, they could see details that no single telescope could reveal.
The European Space Agency, in announcing the image, framed it as part of a larger scientific endeavor. The combined dataset from these two observatories would feed into broader research on star formation—work that would have implications far beyond this single galaxy. More immediately, the observations were being positioned as groundwork for the next generation of space-based astronomy. The James Webb Space Telescope, the most powerful observatory ever built, had launched just months earlier in December 2021. By summer 2022, it would begin its actual science operations, moving through space with the ability to locate distant stars and galaxies and point at them with extraordinary precision.
What makes this moment significant is the layering of capability. Hubble, which has been observing the cosmos since 1990, was being used in concert with ground-based radio astronomy and in preparation for Webb's arrival. Each tool sees the universe differently. Hubble captures visible and ultraviolet light. ALMA detects millimeter and submillimeter radiation—the light given off by cold gas and dust. Webb, when fully operational, would peer even deeper into the infrared, seeing through dust clouds that block visible light entirely. Together, they form a kind of multi-spectrum vision, each instrument compensating for the limitations of the others.
The image of NGC 7496 is, in this sense, a conversation between machines. It is also a conversation between generations of astronomers. The scientists who designed Hubble in the 1980s could not have imagined the precision with which Webb would eventually operate. Yet the work being done now with Hubble and ALMA is explicitly designed to prepare the way for Webb's observations. The data being gathered is not just about understanding this one galaxy. It is about building a foundation of knowledge that will make Webb's observations more meaningful when they arrive.
For the general observer, the image is simply striking—a spiral galaxy rendered in detail, its arms traced in light, its structure laid bare. For the astronomer, it is something else: evidence of how the universe builds itself, one star at a time, in the cold darkness between the stars.
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This treasure trove of data from two of the world's most capable observatories will contribute to wider research into star formation, as well as paving the way for future science with the James Webb Space Telescope.— European Space Agency
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Why combine Hubble with a radio telescope to look at the same galaxy? Aren't they seeing the same thing?
Not at all. Hubble sees visible light—the light our eyes would see if we were close enough. ALMA sees radio waves from cold gas and dust. They're looking at completely different parts of the story. Hubble shows you the stars that have already formed. ALMA shows you the raw material where new stars are being born.
So the cold gas clouds—those are the nurseries?
Exactly. And they're mostly invisible to Hubble. They're too cold, too dark. But ALMA can see right through them. When you combine both datasets, you get the full picture: the finished stars and the unfinished ones.
And this matters because of Webb?
Yes. Webb is coming online with even more power, but the scientists need to know what questions to ask first. This work with Hubble and ALMA is like writing the script. By the time Webb starts observing, astronomers will know exactly what to look for.
Is NGC 7496 special in some way, or just a convenient target?
It's a good laboratory. It's close enough—cosmically speaking—that we can see fine detail, but far enough away that it's genuinely distant. And it's actively forming stars. That's what makes it worth the observation time.
What happens next?
The data gets analyzed, published, shared with other teams. And then Webb starts looking at similar galaxies, but with even sharper vision. This image is part of the foundation.