In terms of light-gathering capability, the most important component of a telescope is its primary mirror. The larger the mirror, the more light it can collect, and the smaller, dimmer, and more distant objects it can detect. Webb’s mirror has an area more than 5 times greater than Hubble’s and 45 times greater than Spitzer’s.
Credits
Image
STScI
3D Model
NASA, ESA, STScI
