After 17 years of construction and testing, Webb was launched into orbit in 2021 as a successor to the Hubble and Spitzer Space Telescopes. Built to create high-resolution images by detecting infrared light, scientists expect that Webb will be able to look farther and deeper into space than we’ve ever seen before.
Looking Into the Deep Past
Telescopes allow us to look into the past, rather than see objects as they are now. The further an object is from the telescope, the longer it takes light emitted from the object to reach us. It takes about 8 minutes for light to travel to Earth from the Sun, so on sunny days, you’re seeing the sun 8 minutes in the past.
Now imagine you’re looking at an object one billion light years away. Light from that object has been traveling towards us for one billion years! So when we look at that object in the telescope we’re seeing what it looked like when that light first left the object a billion years ago.
One of first images Webb has taken is a deep field image. This image looks towards a very small, distant part of the cosmos and took 12.5 hours for the telescope to capture. Webb is able to look so far, we can view some of these galaxies as they were about a billion years after the big bang! The farthest galaxy appears to be 13.1 billion years old. Some of the galaxies in the image appear stretched or distorted. Those galaxies are much further away from us and the light they emit is distorted by the immense gravitational pull of galaxies in the foreground.
What’s Next for Webb?
Webb will continue to look deep into the history of our universe, looking for some of the earliest star formation, but will also look at places closer to home, like the outer planets and other structures in our solar system. We may even learn more about exoplanets, planets in other solar systems!