Hubble, in its 36th year of operation, released a new spectacular image of the Trifid Nebula and showed that the universe changes even on a human timescale
NASA’s and ESA’s Hubble Space Telescope marked its 36th anniversary by releasing a new, exceptionally detailed image of part of the Trifid Nebula, a vast star-forming region located about 5,000 light-years from Earth in the constellation Sagittarius. It is a scene that Hubble first recorded back in 1997, and the new observation now provides a rare insight into changes that, on cosmic scales, are happening almost before our eyes. That is precisely one of the reasons why this anniversary release is important both scientifically and symbolically: it shows that even structures usually perceived as almost motionless can reveal measurable changes within a single human working lifetime. The new image was released on April 20, 2026, a few days before the 36th anniversary of Hubble’s launch on April 24, 1990, and according to NASA and ESA it is one of the most striking examples of how the longevity of a space telescope turns an archive into a tool for tracking the evolution of the universe.
A second look at the same place revealed how much 29 years means in astronomy
For astronomy, it is especially valuable that Hubble did not image an unknown region, but rather the same part of the nebula to which it returned after 29 years. A comparison of the image from 1997 and the one from 2026 shows that certain jets of plasma, clumps of gas, and the edges of dusty structures have shifted, expanded, or changed shape enough for instruments to register them clearly. NASA states that the new observation was also made possible by the fact that the telescope now has the more advanced Wide Field Camera 3, installed during the fourth servicing mission, which has a wider field of view and greater sensitivity than the older camera used in the late 1990s. In practice, this means that the new image is not only sharper and deeper, but also significantly more useful for comparison with historical data. Hubble is therefore no longer just an instrument that records fascinating scenes, but also a precise chronicler of changes in regions where stars are born, shaped, and influence their own surroundings.
The Trifid Nebula, also known as Messier 20 or M20, has long been attractive to astronomers precisely because it combines several processes in a relatively small area: star formation, the action of intense ultraviolet radiation from massive stars, the erosion of clouds of gas and dust, and the appearance of jets of material expelled by young stars in formation. In the new Hubble image, these processes are not presented as an abstract scientific model, but as a visually extremely layered scene. The upper left part of the frame is filled with the bluish glow of ionized gas, while wavy brown and orange shapes of dense dust stretch across the center and right side. The far right part is almost completely dark, indicating a region where the dust is so dense that it blocks most of the visible light. Such an arrangement of colors and brightness is the result of physical processes within the nebula itself, not merely aesthetic processing of the image.
Massive stars shape the environment for hundreds of thousands of years
According to NASA, several massive stars located outside the frame itself have been shaping that region for at least 300,000 years. Their intense ultraviolet radiation and stellar winds blow a huge bubble in the interstellar medium, compress gas and dust, and in doing so trigger new waves of star formation. This is one of the key motifs of the entire image: in the same picture, both the destructive and creative consequences of the action of massive stars can be seen. Radiation tears apart cold clouds, strips electrons from gas, and creates a glow, but at the same time the compression of material can trigger the formation of new stellar cores. That is precisely why nebulae such as the Trifid are not merely decorative objects, but natural laboratories in which scientists observe how cosmic matter transforms from a diffuse cloud into new stars and planetary systems.
The central motif of the new image is especially interesting because of its unusual shape. NASA and ESA point out that the structure resembles a sea slug, specifically a so-called sea lemon, so in the popular description it has been dubbed a “cosmic sea lemon.” That rustically colored head and undulating body are actually a dense cloud of gas and dust gliding through the visual frame like a creature immersed in the dark ocean of space. Behind the poetic impression lies very concrete physics: at the top of that cloud are zones where the material is still condensing, while around it the ultraviolet radiation from neighboring stars erodes and stratifies the outer layers. That is why the scene appears at once alive, fragile, and dynamic.
Herbig-Haro 399 and traces of activity from young stars
The most attention in the expert interpretation is drawn by the left “horn” of that cloud, part of the object known as Herbig-Haro 399. It is a jet of plasma that a young protostar periodically ejects over the course of centuries. It is precisely the comparison of the two imaging epochs that allowed astronomers to see how that jet expanded, enabling them to estimate more directly the speeds of outflowing matter and the amount of energy the young star transfers to its surroundings. Such estimates are important because they help explain how newly formed stars regulate their own growth and how their activity disrupts or reshapes the surrounding cloud from which they formed. Alongside the left jet, traces of a so-called counterjet can also be seen, jagged orange and red lines descending down the darker part of the cloud. This further confirms that it is an active system in which a young star ejects material in opposite directions.
On the opposite, darker, and triangular “horn,” there is another young star. Enlarged views show a faint red point with a small jet, while the greenish arc above it, according to NASA’s interpretation, may be a sign that intense ultraviolet radiation from the surroundings is eroding the circumstellar disk of material surrounding it. If that interpretation is correct, it is a moment in which external conditions are literally shaping the final stages of a star’s formation. The clearer space around that protostar also suggests that the process of its formation may be nearing its very end. The frame also contains a number of other, subtler traces of activity: wavy lines, sharp red streaks, and narrow ridges that indicate additional jets from deeply buried stellar embryos.
Why the image shows blue, yellow, brown, and almost black parts
One of the special features of Hubble’s anniversary image is that it simultaneously feels artistic and didactic. The more bluish parts toward the upper left edge indicate regions where the gas is strongly ionized, that is, where electrons have been separated from atoms under the influence of radiation from massive stars. Yellowish flows of gas, especially at the top of the central cloud, show where ultraviolet radiation is literally “striking” the darker material and beginning to break it apart. Brown and dark red ridges represent denser gas and dust that are still resisting that erosion and that, according to explanations from ESA and NASA, will survive for millions more years before being completely dispersed or turned into new stars. The almost black corners of the image are not merely an absence of light, but regions of the greatest dust density, where visible light struggles to make its way to the telescope.
The image also shows bright orange spheres, stars that have already completed their formation and cleared the immediate space around themselves. This is an important reminder that a single nebula contains a whole range of developmental stages: from dense, almost opaque knots where protostars are only just taking shape, through active jets of material, to fully formed stars that have already swept away the remnants of the cloud from their surroundings. The Trifid is therefore an excellent example of how the past, present, and future of stellar life coexist in the same frame. What today looks like a complex cloud of gas and dust could, in a few million years, be a much more diffuse region in which the original nebula will be represented above all by stars.
The anniversary image as a reminder of Hubble’s longevity
The release of the new Trifid image comes at a time when Hubble has behind it more than 1.7 million observations. According to NASA and ESA data, nearly 29,000 astronomers have used Hubble’s data for peer-reviewed scientific papers, resulting in more than 23,000 publications, and almost 1,100 of them were published during 2025 alone. These numbers speak not only of the mission’s longevity, but also of its productivity. Hubble is not an instrument that defined one era and then remained as a symbol of the past, but an observatory that still generates data every day, opens new questions, and remains the foundation of numerous studies. Its archive is at the same time gaining increasing value because, when old images are compared with new ones, changes can be tracked in objects that evolve more slowly than would usually fit within the lifetime of a single mission.
In recent months, Hubble has, according to official ESA releases, contributed to a series of new results showing how scientifically relevant it still is. Among them are the identification of one of the darkest known galaxies, the discovery of hundreds of cosmic anomalies with the help of artificial intelligence, the first observation of catastrophic asteroid collisions in the system around the star Fomalhaut, and a more precise estimate of the size of the interstellar comet 3I/ATLAS. In June 2025, a study was also published that, based on Hubble data and measurements from ESA’s Gaia mission, called into question the earlier almost certain estimate that the Milky Way and Andromeda will inevitably collide. Such examples show that Hubble is important not only because of its historical legacy and iconic photographs, but also because it continues to actively participate in re-examining fundamental astronomical concepts.
Cooperation with Webb and the value of long time series
Additional weight to Hubble’s work is given by the fact that its data are increasingly being combined with observations from other space observatories. NASA states that since 2022, observations from Hubble and the James Webb Space Telescope have been regularly compared and complemented, with Hubble remaining especially important in the ultraviolet and visible part of the spectrum, while Webb probes deeper into the infrared region. In this division of labor, Hubble does not play the role of an older predecessor slowly stepping aside, but of a partner without which the picture of the universe would be incomplete. This is especially evident precisely in the example of the Trifid: Hubble’s ability to monitor the same region in visible light across decades creates a time series of invaluable importance, something that no individual spectacular photograph can provide on its own.
In that sense, the new anniversary image has a double value. For the wider public, it is yet another reminder of why Hubble became the “people’s telescope,” an instrument whose images shaped the popular perception of the universe. For the scientific community, it is another proof that long-term observations of the same object can reveal processes that otherwise could not easily be measured. In the Trifid, therefore, it is not only the beauty of the nebula that is being observed, but also the dynamics of star formation, cloud erosion, and the transfer of energy from young stars into the surrounding interstellar medium. That is the reason why Hubble’s 36th anniversary was marked precisely by returning to an old place: the same scene, after almost three decades, became a new scientific story.
As Hubble enters the 37th year of its mission, the new image of the Trifid Nebula acts simultaneously as a celebration of the endurance of one of the most important scientific platforms of the modern era and as a reminder that the universe is not static. In the depths of the cloud, behind dark bands of dust and in thin jets of plasma, processes are still unfolding that over millions of years will create new stars and reshape the entire region. Hubble’s advantage lies in the fact that it observes those changes not merely as a moment, but as a continuous record. And it is precisely such a record that enables modern astronomy to view the universe not only as a spectacle, but as a process that can be followed, compared, and understood.
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