The limit of what Hubble can see
“Whereas Hubble struggles to get to wavelengths as long as one micron, the James Webb Space Telescope (JWST) will get all the way down to about 30 microns with better sensitivity than anything else that’s come before, with better resolution and some six times the light-gathering power of Hubble!”
You might think that, when it comes to finding the most distant objects in the Universe, all we need is a good telescope, to leave the shutter open, and wait. As we accumulate more and more photons, we’re bound to find the most distant, faint objects out there. Sure, Hubble just broke its own cosmic distance record, but it’s certainly not the most distant. Thinking so misses an important fact: the Universe is expanding! And with that expansion, the wavelength of the light we can see gets redshifted. Ultraviolet light winds up in the infrared, infrared light winds up in the microwave, and the most distant galaxies that are out there are invisible, even to Hubble. Here are Hubble’s limits, and how the James Webb Space Telescope will overcome them.