On April 24, 2025, 35 years have passed since the Hubble space Telescope, the ingenuity that has revolutionized the observation of the universe.
Before the observations of the American astrophysicist that gave him a name, Edwin Hubble, the universe was considered static and eternal. Einstein even defended him in 1917. But Hubble discovered, in 1929, that the galaxies move away from each other. This can only happen if the universe expands and, if it expands, it has a beginning, a big bang.
Decades later, key observations of the Hubble Space Telescope allowed to determine that the already undisputed cosmic expansion accelerates. Thus the disturbing concept of dark energy was born.
The Hubble and the Planets
In 1990, when the Hubble was launched, no planet had been detected outside the solar system. Today the observed exoplanets are counted by thousands. So, not even the information about our neighbors was accurate enough.
The first images in detail of Pluto and his Caronte Moon, as well as the discovery of four moons more orbiting the dwarf planet, have the Hubble seal.
We also owe the snapshots of La Mancha Blanca de Saturno, a great storm in the equatorial region of the planet discovered by amateur astronomers in September 1990 and photographed by the space telescope for several days of observations.
The immensity of the cosmos in all its splendor
Probably the most relevant historical photo was the first deep field of Hubble (HDF-N), taken in 1995 for 10 consecutive days focusing on “the nothingness.” While it was “nothing” what they expected to find, the image revealed 3,000 distant galaxies when the universe had just about 800 million years. It was crucial to understand the structure and evolution of the early universe.
Black holes were born
In 1992, an astronomer team claimed to have found evidence of the existence of a black hole with a dough greater than 2,600 million solar masses in the center of the Giant M87 elliptical galaxy, based on images taken by Hubble.
It would be necessary to wait until 2019 when an International Consortium of Researchers photographed this supermassive black hole for the first time.
The size of a bus
Thanks to its privileged location above the Earth’s atmosphere, the Hubble has a broad and clear vision of the cosmos: distinguishes astronomical objects with an angular diameter of only 0.05 seconds of arc. It would be equivalent to differentiating the thickness of a ten cents coin at a distance of 138 kilometers.
Its dimensions give it immense potential for astronomical observation: 13.2 meters long and 4.2 meters wide in the back, where scientific instruments are housed. The Hubble has an approximate weight of 12 246 kilograms and a size similar to that of a bus.
The observatory is fed by two solar panels that convert sunlight into electrical energy. This is stored in six large batteries that allow it to work in the shadow areas of the porta, when the earth prevents the sun from seeing.
Unprecedented optical quality
From an optical point of view, Hubble is a cassegrain reflector telescope. Unlike refractor telescopes (such as Galileo), it does not have lenses, but mirrors that reflect the light sequentially to direct it towards their registration instruments, cameras and spectrographers.
Its primary mirror is 2.4 meters in diameter and captures an immense amount of light. It detects 10 billion objects of times more faint than those that are seen with the naked eye. It can operate both in the visible and infrared and ultraviolet spectrum, unlike the James Webb space telescope, which specializes in infrared.
Read More: James Webb space telescope: a new window to the farthest and most primitive universe
Unexpected problems
But not everything went perfectly.
Shortly after its launch in 1990, scientists noticed that the primary mirror had an optical defect (called spherical aberration), which affected the sharpness of the images. A service mission had to be sent to correct this problem. In December 1993, an astronaut crew made the necessary repairs to restore the telescope at its planned performance level.
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Possible withdrawal in 2036
Initially, Hubble’s useful life was estimated at about 15 years. But thanks to the five maintenance missions with astronauts, its functionality has been prolonged to date.
How long could it be operational? According to NASA itself, Hubble could be scientifically active during the next decade, with a possible withdrawal date in 2036.
Thinking about him Final outcomean astronaut team installed in the Hubble in 2009 a device that will allow it to capture it, comply with it in orbit and lead it towards a controlled re -entry in the earth’s atmosphere where, finally, it will end up calcined.
The best images in its history
On its 35th anniversary, it is difficult to make a selection of its best historical images. These are some of those collected by NASA to celebrate his birthday:
ETA CARINAE ETA
In this impressive snapshot of the ETA Carinae Supermassive star, the Hubble captured a couple of huge undulating clouds as a result of a gigantic eruption occurred about 150 years ago, becoming one of the brightest stars in the southern sky.
Galaxies collision
The space telescope registered the collision of the Antena galaxies, whose approach began about 200 million years ago. The respective nuclei of the twin galaxies are the orange spots, on the left and the right of the center of the image, intersected by dark dust filaments.
The southern ring nebula
This iconic image is an exceptional example of a planetary nebula, NGC3132 or nebula of the southern ring, where an extensive expanding gas cloud that surrounds a dying star is distinguished. The snapshot shows two stars near the center of the nebula: a white and bright and a weaker companion, in the upper right corner.
ABELL GALAXIAS CUMULO 2218
The impressive cluster of Galaxies Abell 2218 was recorded by the Hubble in 2000. It is a clear example of the relativistic phenomenon known as gravitational lens, where an intense gravitational field (generated by Abell 2218) diverts the light from distant galaxies, similar to as a curved optical lens the light to form an image.
The crab nebula
It is one of the most spectacular images of Hubble. The crab nebula is constituted by the remains of a huge dying star that exploded and expelled its gas layers to interstellar space (a supernova). The orange filaments represent the remains of the star that exploded, formed mainly by hydrogen.
The Pillars of Creation
In 1995 the Hubble made the pillars of creation worldwide, an interstellar gas formation and dust in the eagle nebula, about 6,500 light years from the earth, on the Milky Way. He photographed him again in 2014.
Read More: The Pillars of Creation: the icon of the new universe
