The true test of the amateur astronomer is building their own telescope ... mirrors is a long, arduous process. Instead of lapping the blank by hand, Laurie Hall built this mirror grinding machine ...

Rubin Observatory’s 8.4-meter Simonyi Survey Telescope in Chile has now been equipped with all three of its mirrors ... said ...

like the James Webb Space Telescope, that means that the telescopes' primary mirror is 6.6 meters across. The bigger the primary mirror of a telescope is, the more light it can collect at one time.