# Can we make a curved mirror out of many small flat mirrors in telescopes?

Will it be possible to build a telescope using many small flat mirrors as a replacement for the prime curved telescope mirror?

If the answer is yes, can you please provide a formula connecting the telescope's aperture size and the maximum flat mirror size to make this work?

• @IlyaGazman At what point would you say that a disco ball looks like a mirrored sphere? I bet you could tell the difference by eye even if each mirror were 1 mm$^2$. The light from a telescope needs to be focused with extreme precision - there's a reason that telescope mirrors are expensive. – J. Murray Jan 21 at 4:29