For over thirty years, astronomers have relied on the Hubble Space Telescope for crewless space exploration and research. Launched into space on April 24, 1990, Hubble began its rapid orbit of the Earth, detecting objects 60,000 fainter than the human eye can see and snapping images of far-off galaxies over 13 billion light-years away.
That said, though nothing short of a modern marvel, Hubble had its limitations. And with ever-improving technology, scientists at NASA knew they could create something better. So on Christmas Day 2021, they launched the James Webb Telescope into orbit. The largest and most powerful space telescope ever created, the JWST orbits the Sun rather than the Earth, collecting data and capturing images of galaxies, stars, and planets with eye-popping clarity.
James Webb Telescope Spots Oldest Known Galaxies
In less than a year, the James Webb Telescope has snapped unbelievable images of dying stars and galaxy clusters billions of light-years away, as well as comets, asteroids, and Kuiper Belt objects. It’s so powerful that it can even monitor the weather of planets and their moons.
Its most recent discovery, however, was the most interesting to date. In its space travels, the James Webb Telescope found the oldest galaxies confirmed to date. According to NASA, the light from the galaxies took a staggering 13.4 billion years to reach Earth because they date back to just 400 million years after the Big Bang, when the universe was only 2% of its current age.
“It was crucial to prove that these galaxies do, indeed, inhabit the early universe. It’s very possible for closer galaxies to masquerade as very distant galaxies,” astronomer and co-author Emma Curtis-Lake explained in a release from NASA. “Seeing the spectrum revealed as we hoped, confirming these galaxies as being at the true edge of our view, some further away than Hubble could see! It is a tremendously exciting achievement for the mission.”
JWST Snaps Pictures of Galaxies’ Pasts
In 2015, NASA launched the JADES program (JWST Advanced Deep Extragalactic Survey) in collaboration with more than eighty astronomers across ten countries. Its purpose? To provide us with a view of the early universe in stunning detail using the power of the James Webb Telescope.
The images captured by JWST of the Ultra Deep Field (a small patch of sky that’s been the target of virtually all telescopes for over 20 years) contain nearly 100,000 galaxies, each at a different moment in its history, depending on its proximity to Earth. All, however, are billions of years in the past.
“For the first time, we have discovered galaxies only 350 million years after the big bang, and we can be absolutely confident of their fantastic distances,” explained co-author Brant Robertson. “To find these early galaxies in such stunningly beautiful images is a special experience.”
Though these galaxies are impossibly far from us, astronomers are able to explore their properties with ease thanks to the incredible power of the James Webb Telescope.
“It is hard to understand galaxies without understanding the initial periods of their development,” said astronomer and co-author Sandro Tacchella. “Much as with humans, so much of what happens later depends on the impact of these early generations of stars. So many questions about galaxies have been waiting for the transformative opportunity of Webb, and we’re thrilled to be able to play a part in revealing this story.”