Hubble's Greatest Hits: 35 Years of Universe-Altering Images

While Hubble was trained on the Frontier Fields — a set of massive galaxy clusters chosen to serve as gravitational lenses — its second camera automatically captured this parallel field in the Sculptor constellation. Thousands of colourful galaxies swim in the inky blackness at distances too vast for conventional comprehension. Each point of light is not a star but an entire galaxy containing hundreds of billions of stars, many of them orbited by planets. The image is a reminder that what we see when we look at the night sky is only the nearest fraction of what exists.

By combining data from the Spitzer Space Telescope and Hubble, astronomers identified galaxies so distant and so faint that Spitzer's infrared vision was required to detect them at all. The small circles mark the most remote objects in this field — galaxies seen as they were when the universe was less than a billion years old. This kind of multi-telescope collaboration became standard practice in the 2010s, with each observatory contributing wavelengths of light invisible to the others, building up composite portraits of cosmic structures that no single instrument could see alone.

The eXtreme Deep Field, assembled in 2012 from ten years of Hubble observations totalling two million seconds of exposure time, pushed the boundary of visibility to galaxies formed just 450 million years after the Big Bang. It covers an area of sky one-thirteenth the diameter of the full moon and contains approximately 5,500 galaxies in that tiny patch alone. For a decade it stood as humanity's deepest portrait of the cosmos, until the James Webb Space Telescope launched in late 2021 and immediately surpassed it.

The Ultraviolet Coverage of the Hubble Ultra Deep Field study in 2014 added ultraviolet wavelengths to the existing visible and near-infrared mosaic, producing the most complete colour portrait of the universe ever assembled. The resulting image captures the life cycles of stars across 12 billion years of cosmic time — from hot young blue-white giants to cooling red giants preparing to shed their outer layers. Astronomers used it to study how star formation rates changed across different epochs of the universe's history.

Dubbed "the Tadpole," this warped spiral galaxy (UGC 10214) was the first image captured by Hubble's Advanced Camera for Surveys after it was installed during the 2002 servicing mission. A smaller galaxy had passed through the Tadpole's disc millions of years earlier, leaving behind a 280,000-light-year trail of tidally stripped stars — the "tail" visible here. In the background, behind the Tadpole, more than 3,000 additional galaxies are visible, each a reminder that cosmic collisions and mergers are not catastrophes but the ordinary business of a restless universe.

The Crab Nebula is the wreckage of a star that exploded in 1054 AD — a supernova so bright that Chinese and Japanese astronomers recorded it as visible in daylight for three weeks. This composite image combines Herschel Space Observatory's far-infrared view with Hubble's optical data, revealing the filamentary structure of ejected material still expanding outward at 1,500 kilometres per second. At the nebula's heart sits a rapidly spinning neutron star — the collapsed remnant of the original star — rotating 30 times per second and energising the entire structure.

The Cat's Eye Nebula (NGC 6543) is one of the most geometrically complex planetary nebulae known, containing eleven concentric shells of gas expelled by a dying star over the last several thousand years. Each shell represents a distinct episode in the star's death throes as it exhausted its nuclear fuel. The bright inner eye is illuminated by ultraviolet radiation from the hot central white dwarf, now the contracted remnant of what was once a star perhaps five times more massive than our Sun. In roughly five billion years, our own Sun will produce a structure that looks something like this.

This turbulent scene shows N159, a stellar nursery over 150 light-years across in the Large Magellanic Cloud — a satellite galaxy of the Milky Way visible from the Southern Hemisphere. The HII region contains dozens of massive hot young stars whose ultraviolet radiation and stellar winds are carving cavities and sculpting pillars in the surrounding gas and dust. N159 is one of the most actively star-forming regions within any satellite galaxy, and Hubble's resolution reveals individual protostars emerging from their dusty cocoons.

For Hubble's 23rd launch anniversary in 2013, the telescope was turned toward one of the most recognisable structures in the sky: the Horsehead Nebula in Orion. But this time it captured the nebula in infrared light rather than visible wavelengths, piercing the obscuring dust clouds to reveal the glowing gas and newly forming stars hidden inside the horse-shaped pillar. The image was so striking that it immediately became one of the most downloaded in Hubble's archive, a reminder that familiar objects look entirely different when viewed through different eyes.

While Hubble was trained on the Frontier Fields — a set of massive galaxy clusters chosen to serve as gravitational lenses — its second camera automatically captured this parallel field in the Sculptor constellation. Thousands of colourful galaxies swim in the inky blackness at distances too vast for conventional comprehension. Each point of light is not a star but an entire galaxy containing hundreds of billions of stars, many of them orbited by planets. The image is a reminder that what we see when we look at the night sky is only the nearest fraction of what exists.

By combining data from the Spitzer Space Telescope and Hubble, astronomers identified galaxies so distant and so faint that Spitzer's infrared vision was required to detect them at all. The small circles mark the most remote objects in this field — galaxies seen as they were when the universe was less than a billion years old. This kind of multi-telescope collaboration became standard practice in the 2010s, with each observatory contributing wavelengths of light invisible to the others, building up composite portraits of cosmic structures that no single instrument could see alone.

The eXtreme Deep Field, assembled in 2012 from ten years of Hubble observations totalling two million seconds of exposure time, pushed the boundary of visibility to galaxies formed just 450 million years after the Big Bang. It covers an area of sky one-thirteenth the diameter of the full moon and contains approximately 5,500 galaxies in that tiny patch alone. For a decade it stood as humanity's deepest portrait of the cosmos, until the James Webb Space Telescope launched in late 2021 and immediately surpassed it.

The Ultraviolet Coverage of the Hubble Ultra Deep Field study in 2014 added ultraviolet wavelengths to the existing visible and near-infrared mosaic, producing the most complete colour portrait of the universe ever assembled. The resulting image captures the life cycles of stars across 12 billion years of cosmic time — from hot young blue-white giants to cooling red giants preparing to shed their outer layers. Astronomers used it to study how star formation rates changed across different epochs of the universe's history.

Dubbed "the Tadpole," this warped spiral galaxy (UGC 10214) was the first image captured by Hubble's Advanced Camera for Surveys after it was installed during the 2002 servicing mission. A smaller galaxy had passed through the Tadpole's disc millions of years earlier, leaving behind a 280,000-light-year trail of tidally stripped stars — the "tail" visible here. In the background, behind the Tadpole, more than 3,000 additional galaxies are visible, each a reminder that cosmic collisions and mergers are not catastrophes but the ordinary business of a restless universe.

The Crab Nebula is the wreckage of a star that exploded in 1054 AD — a supernova so bright that Chinese and Japanese astronomers recorded it as visible in daylight for three weeks. This composite image combines Herschel Space Observatory's far-infrared view with Hubble's optical data, revealing the filamentary structure of ejected material still expanding outward at 1,500 kilometres per second. At the nebula's heart sits a rapidly spinning neutron star — the collapsed remnant of the original star — rotating 30 times per second and energising the entire structure.

The Cat's Eye Nebula (NGC 6543) is one of the most geometrically complex planetary nebulae known, containing eleven concentric shells of gas expelled by a dying star over the last several thousand years. Each shell represents a distinct episode in the star's death throes as it exhausted its nuclear fuel. The bright inner eye is illuminated by ultraviolet radiation from the hot central white dwarf, now the contracted remnant of what was once a star perhaps five times more massive than our Sun. In roughly five billion years, our own Sun will produce a structure that looks something like this.

This turbulent scene shows N159, a stellar nursery over 150 light-years across in the Large Magellanic Cloud — a satellite galaxy of the Milky Way visible from the Southern Hemisphere. The HII region contains dozens of massive hot young stars whose ultraviolet radiation and stellar winds are carving cavities and sculpting pillars in the surrounding gas and dust. N159 is one of the most actively star-forming regions within any satellite galaxy, and Hubble's resolution reveals individual protostars emerging from their dusty cocoons.

For Hubble's 23rd launch anniversary in 2013, the telescope was turned toward one of the most recognisable structures in the sky: the Horsehead Nebula in Orion. But this time it captured the nebula in infrared light rather than visible wavelengths, piercing the obscuring dust clouds to reveal the glowing gas and newly forming stars hidden inside the horse-shaped pillar. The image was so striking that it immediately became one of the most downloaded in Hubble's archive, a reminder that familiar objects look entirely different when viewed through different eyes.