If we compare Webb to the Hubble Space Telescope (because everyone has heard of Hubble) it’s another telescope that’s going to be launched into space and is going to have a lot of similarities to Hubble, but also lots of differences. Hubble is in what we call low Earth orbit. It’s just a few hundreds of kilometres above the Earth. But James Webb will be located 1.5 million kilometres away from Earth, considerably farther away, about four times the Earth-Moon distance. It’s going to be much larger than Hubble as well. It has a 6.5 metre wide telescope. Hubble has a 2.4 metre wide telescope.
The James Webb Space Telescope. Photo provided.
Another key difference is that James Webb will be looking in a type of light called infrared. Hubble looks in mostly visible wavelengths, which is what the human eye can see. James Webb’ll be probing the universe in infrared (wavelengths). Often we see in science fiction movies, people will have infrared glasses to have night vision. Humans and animals emit quite brightly in the infrared. But lots of interesting things in space also emit brightly in the infrared, notably planets, which is something that we’re very excited about observing with James Webb—discovering new planets beyond our solar system.