Move over Hubble — a bigger, more advanced, and the arguably better telescope has entered the galaxy. Launched on Christmas Day, the James Webb Telescope is now NASA’s most powerful telescope and will allow scientists to dig deep into the universe’s past. Using images captured with the James Webb Telescope, scientists hope to catch a glimpse of the earliest moments of our universe and to study early planetary system formation, among other things.
So how can a telescope give us a peek into events that occurred a long, long time ago, in a galaxy far, far away? The universe is a vast place and it can take a long time for light to travel from one place to another. The sun’s light, for example, takes over eight minutes to reach us.
The closest galaxy to our own, the Andromeda Galaxy, is approximately 2.5 million light-years away. That means when we capture life from the Andromeda Galaxy, the light itself has been traveling for roughly 2.5 million years to reach us. Thus, using powerful telescopes, astronomers can collect this ancient light and take a peek into the past.
The more powerful the telescope, the further it can see into the past. The Hubble telescope can collect light from roughly 400 million years after when scientists estimate the Big Bang occurred. The James Webb is expected to look back to just 250 million years after the Big Bang.
It took nearly a month for the James Webb Telescope to get to its Lagrange point, which is where the telescope can permanently rest in a stable orbit. The James Webb ultimately cost roughly $10 billion — a bargain price to help humanity unlock some of the mysteries of the universe.