In 2002, NASA astronauts installed the Advanced Camera for Survey (ACS) camera on the Hubble. They knew it was necessary but had no idea it would lead to so many amazing discoveries. The Hubble telescope is the most iconic and legendary space telescope of all time. It has been shooting breathtaking images of the cosmos and disrupting science since 1990.

The James Webb Telescope, launched in December 2021, is now joining forces with Hubble to continue the exploration of distant worlds, galaxies, black holes and the mysteries of the early universe. Space telescopes are also heavily used by NASA to get accurate data and visuals to better plan for solar system missions.

Related: Here’s How NASA Is Aligning The James Webb Telescope’s Mirrors

NASA honored the 20th anniversary of the ACS onboard Hubble. The camera was not launched with the telescope but installed during the Space Shuttle mission 3B by astronauts. The camera suffered a malfunction in 2007, and a new mission managed to get 70 percent of its capacity back to work. The most famous image of the ACS is an image of thousands of small distant galaxies in full detail in one single black frame. However, its achievements go well beyond that still.

Open Your Eyes Into The Deep Universe

The ACS camera started by working on what NASA called the Hubble Ultra Deep Field. Space telescopes are more than just optical wonders of engineering. As they peer further and further into deep space, they look at the light that shined billions of years ago. The further the light of a star or a galaxy is, the longer it takes for its light to reach us. The Hubble’s Deep Field camera is the first long-distant space-time traveler. It opened up a vision of what the universe looked like 13.35 billion years ago.

The Frontier Fields was the work that followed the Ultra Deep Field. Using the ACS, the Hubble leveraged the laws of physics using gravitational forces of stars that bend and warp light as a lens to peer even further into the unknown. The ACS used long exposures of one million seconds to reveal the “Dark Ages” of galaxies in formation. The camera also revealed black hole mysteries and discovered light echos, a strange phenomenon where erupting stars echo light bouncing off cosmic dust.

Thanks to the ACS camera, we now know that the Milky Way Galaxy is on a collision course with the Andromeda Galaxy. The event that is expected to happen in four billion years tells a lot about the nature and momentum of galaxies. The ACS also gave scientists clues about how the universe is accelerating and the role of dark energy. “The Advanced Camera for Surveys has opened our eyes to a deep and active universe for two decades,” NASA says.