The venerable Hubble Space Telescope continues to redefine our understanding of the cosmos as it celebrates an extraordinary milestone this week – 35 years of uninterrupted observation from Earth orbit.
To mark the occasion, NASA and the European Space Agency have released a collection of stunning new images showcasing Hubble’s remarkable capabilities, from detailed observations of Mars to dramatic stellar nurseries and distant galaxies.
Against all odds, the telescope that fundamentally transformed human understanding of the universe remains at the peak of its scientific capabilities, with demand for observation time at a staggering 6-to-1 ratio of applications to available slots.
![The Hubble Space Telescope captured in exquisite detail a face-on view of a remarkable-looking galaxy. NGC 5335 is categorized as a flocculent spiral galaxy with patchy streamers of star formation across its disk. There is a striking lack of well-defined spiral arms that are commonly found among galaxies, including our Milky Way. A notable bar structure slices across the center of the galaxy. The bar channels gas inwards toward the galactic center, fueling star formation. Such bars are dynamic in galaxies and may come and go over two-billion-year intervals. They appear in about 30 percent of observed galaxies, including our Milky Way. [Image description: Barred spiral galaxy NGC 5335 observed by the Hubble Space Telescope takes up the majority of the view. At its center is a milky yellow, flattened oval that extends bottom left to top. Within the oval is a bright central region that looks circular, with the very center the brightest. In the bright central region is what looks like a bar, extending from top left to bottom right. Around this is a thick swath of blue stars speckled with white regions. Multiple arms wrap up and around in a counterclockwise direction, becoming fainter the farther out they are. Both the white core and the spiral arms are intertwined with dark streaks of dust. The background of space is black. Thousands of distant galaxies in an array of colors are speckled throughout.]](https://scienceblog.com/esa/wp-content/uploads/sites/13/2025/04/Barred_Spiral_Galaxy_NGC_5335_pillars.jpg)
The telescope’s journey has been anything but smooth. From an initial spherical aberration in its primary mirror that threatened the entire mission to five high-risk servicing missions by space shuttle crews between 1993 and 2009, Hubble’s story is one of human ingenuity overcoming seemingly insurmountable challenges.
These heroic interventions by astronauts, including European Space Agency team members on two of the missions, have enabled Hubble to make nearly 1.7 million observations of approximately 55,000 astronomical targets. The resulting scientific discoveries have generated over 22,000 research papers with more than 1.3 million citations as of February 2025.
Before Hubble’s launch in 1990, our view of the cosmos was severely limited by Earth’s atmosphere. Ground-based telescopes could see only halfway across the universe, and estimates for the age of the cosmos varied widely. Supermassive black holes remained theoretical entities, and no planets had been confirmed beyond our solar system.
![This Hubble Space Telescope image captures the beauty of the moth-like planetary nebula NGC 2899. This object has a diagonal, bipolar, cylindrical outflow of gas. This is propelled by radiation and stellar winds from a nearly 22 000 degree Celsius white dwarf at the center. In fact, there may be two companion stars that are interacting and sculpting the nebula, which is pinched in the middle by a fragmented ring or torus – looking like a half-eaten donut. It has a forest of gaseous “pillars” that point back to the source of radiation and stellar winds. The colours are from glowing hydrogen and oxygen. The nebula lies approximately 4,500 light-years away in the southern constellation Vela. [Image description: The planetary nebula NGC 2899 is shaped like a single macaroni noodle, with its edges pointed up, but its edge-on central torus is semi-transparent in the middle. The top and bottom edges are thick and orange. The center is semi-transparent blue and green. The wider central region looks roughly like a moth, also filled with semi-transparent blue and green. There are two pinpoint-like white stars with diffraction spikes toward the center. Immediately below them, slightly toward the right, is a smaller blue orb, a central star. The next layer of gas and dust is whiter, with some thicker pillars that look like they are rising up at bottom center. The colour fades into reds and purples, and then to orange ]](https://scienceblog.com/esa/wp-content/uploads/sites/13/2025/04/Planetary_nebula_NGC_2899_pillars.jpg)
Among the telescope’s most significant contributions are precise measurements of the universe’s expansion rate, confirmation that supermassive black holes exist at the centers of most galaxies, the first analysis of exoplanet atmospheres, and critical observations leading to the discovery of dark energy – the mysterious force accelerating cosmic expansion.
The anniversary image collection showcases Hubble’s versatility. New observations of Mars reveal water-ice clouds giving the Red Planet a frosty appearance as its northern polar cap experiences the beginning of Martian spring. The planet was approximately 98 million kilometers from Earth when these images were captured in late December 2024.
![This is a combination of Hubble Space Telescope images of Mars taken from December 28th to 30th, 2024. At the midpoint of the observations, Mars was approximately 98 million kilometres from Earth. Thin water-ice clouds that are apparent in ultraviolet light give the Red Planet a frosty appearance. The icy northern polar cap was experiencing the start of Martian spring. In the left image, the bright orange Tharsis plateau is visible with its chain of dormant volcanoes. The largest volcano, Olympus Mons, pokes above the clouds at the 10 o’clock position near the northwest limb. At an elevation of 21 000 metres, it is 2.5 times the height of Mt. Everest above sea level. Valles Marineris, Mars’ roughly 4,000 kilometre-long canyon system, is a dark, linear, horizontal feature near center left. In the right image, high-altitude evening clouds can be seen along the planet’s eastern limb. The 2,250-kilometre-wide Hellas basin, an ancient asteroid impact feature, appears far to the south. Most of the hemisphere is dominated by the classical “shark fin” feature, Syrtis Major. [Image description: Two views of planet Mars on a black background of space observed by the Hubble Space Telescope. At left, text: December 28, 2024 20:00 UT. At right, text: December 29, 2024 13:18 UT. In both images, its atmosphere is clear and the surface appears detailed. Most of the planet is shades of orange. At left, the brightest orange area appears in the left half. At right, the brightest orange area is centered and takes on the rough shape of a sleeping mask. In both views, darker surface features are noticeable on the lower half of the planet. These have a mix of orange, blue, and gray hues. At the top and bottom, white regions mark the planet’s polar caps. The entire limb of the planet, its visible edge, has a blue hue. The blue doesn’t form an even circle at the edges, and appears thinner toward the left and right, and thicker in some areas.]](https://scienceblog.com/esa/wp-content/uploads/sites/13/2025/04/Mars_December_2024_pillars.jpg)
Another highlight is a small portion of the massive Rosette Nebula, a star-forming region spanning 100 light-years located 5,200 light-years from Earth. Hubble’s image focuses on just a 4-light-year section, roughly the distance between our Sun and Alpha Centauri, revealing dark hydrogen clouds being sculpted by radiation from nearby massive stars.
The barred spiral galaxy NGC 5335 rounds out the collection, showcasing patchy star formation across its disk rather than the well-defined spiral arms common in many galaxies. Its central bar structure, which “channels gas inwards toward the galactic center, fueling star formation,” appears in approximately 30 percent of observed galaxies, including our own Milky Way.
European astronomers have made particularly effective use of Hubble, consistently securing more than the 15% of observing time guaranteed through ESA’s participation in the mission. Their discoveries include evidence for intermediate-mass black holes, extraordinarily bright explosions far from any host galaxy, and most notably, the identification of Earendel in 2022 – the most distant single star ever observed, seen as it existed 12.9 billion years ago when the universe was less than a billion years old.
Beyond deep space, Hubble continues to reveal secrets within our solar system. The OPAL program recently celebrated a decade studying the outer planets, discovering water vapor on Jupiter’s moons Europa and Ganymede, mysterious “spokes” in Saturn’s rings, and monitoring changes in the size of Jupiter’s Great Red Spot.
Perhaps most remarkably, Hubble has transitioned from pioneer to partner, now working in tandem with the James Webb Space Telescope to provide complementary observations across different wavelengths. Webb itself might never have been built without Hubble first revealing what its designers call an “undiscovered country” of countless distant galaxies.
“Unlike any other telescope before it, Hubble has made astronomy very relevant, engaging, and accessible for people of all ages,” notes the anniversary statement. “Hubble became ‘the people’s telescope,’ touching the minds as well as the emotions of hundreds of millions of humans around the globe.”
As Hubble enters its 36th year of operation, it shows no signs of slowing down. With its immense archive of more than 400 terabytes of data and continued production of groundbreaking science, the telescope that fundamentally changed humanity’s perception of the cosmos remains an indispensable tool in astronomers’ quest to understand the universe.
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