The five pictures that changed the history of science

The James Webb Telescope is about to depart for space, where it will observe the universe in infrared near the Big Bang. And if it succeeds, it will push the boundaries of our astronomical knowledge that its predecessor, the Hubble Space Telescope, made. It was April 24, 1990, when five astronauts aboard the space shuttle Discovery put the space telescope into orbit 600 kilometers above the Earth’s surface. After solving a problem with mirrors – which didn’t allow us to accurately observe things in the universe – thanks to a mission with another space shuttle in 1993, Hubble’s eye began showing things we hadn’t seen before, bringing us closer to the limits of time and space.

Starting with our solar system, it has allowed us, year after year, to photograph the planets, to observe the general evolution of their atmosphere or to photograph truly unique phenomena. Like, for example, watch the extreme flyby of Comet Schoemaker-Levy 9 crushed by Jupiter’s gravity as it passed in the summer of 1992. Two years later, Hubble followed the shrapnel as it plunged into the nucleus. Joe buyer. She then transmitted moving images of the traumatic scars.

Over the years, he documented the turbulent birth of stars almost everywhere in our galaxy. With his infrared observation tools, he was able to pierce through the clouds of dust surrounding the Star Cradle, revealing them like we’d never seen before. One of the most exciting images he has released for us is the one in which you can see dust discs around some newborn stars hidden in the depths of the Orion Nebula. There, entirely new solar systems are born, just as ours were born four and a half billion years ago.

Stars often end their lives catastrophically, disintegrating in giant star explosions known as supernovae. For a few glorious months, it could become one of the brightest things in the entire universe, surpassing every other star in its galaxy in splendor. Among them, Hubble witnessed the scene of a supernova in 1987. The telescope observed a ring of gas formed around the point of the supernova explosion. Over the years, I’ve watched some bright spots appear along the ring, like a cameo on a necklace. These cosmic pearls were ignited by supersonic shock waves released when the star exploded.

Then he studied and photographed galaxies, which are huge islands of stars like ours, which contain hundreds of billions within them. And although the universe is made up of more vacuum than matter, galaxies can collide. Don’t forget the Bullet Cluster photo where two giant groups of galaxies collide about 3 billion 720 million light-years away from us.

Then “check” what’s happening near black holes. Each galaxy has a black hole in its core, and Hubble has studied the movement of nearby stars, collecting data that allowed us to obtain the masses of black holes. What is in the center of our galaxy, for example, has a mass 4 million times the mass of the Sun. Hubble also allowed us to observe ‘gravitational lenses’.

They are a kind of mirage of the universe. They form because gravity bends space and thus deflects light rays. So it turns out that light from distant galaxies is distorted and amplified by the gravitational field of objects (such as very massive galaxies) that it encounters on its way to Earth. It’s like looking through a large magnifying glass and the result is the so-called “gravitational lens” effect.

Also thanks to Hubble, when measuring the “redshift” (a phenomenon similar to what happens with the sound of an ambulance siren when it moves away from the listener: the sound is “stretched” precisely because the ambulance itself is being pulled) the farthest objects it could locate at the start of the light , hence the age of the universe, which turned out to be 13 billion 800 million years.

Then there is the iconic image not only of what Hubble was able to observe, but of all of humanity: the “ultra-deep field”. It is an image that shows about 10,000 galaxies of different ages, sizes, shapes and colors. The youngest red galaxies, about 100, may be among the most distant known to have existed when the universe was only 800 million years old. The first galaxies – the largest, brightest and most famous spiral and elliptical galaxies – formed about a billion years ago, when the universe was 13 billion years old. The image required 800 exposures, taken during Hubble’s 400 orbits around the Earth. The total exposure time was 11 and a half days. But Hubble’s life is not over yet. Your observations will continue with those from the James Webb Telescope.