(a) Using the Rayleigh criterion, estimate the theoretical diffraction limit for the angular resolution of a typical 20-cm (8-in) amateur telescope at 550 nm. Express your answer in arcseconds.
(b) Using the information in Appendix C, estimate the minimum size of a crater on the Moon that can be resolved by a 20-cm (8-in) telescope.
(c) Is this resolution limit likely to be achieved? Why or why not?