Question

Professional research telescopes should be large enough to gather sufficient radiation from space. Which of these statements best explains why a reflecting telescope is is best used as a professional research telescope?

Answer 1

A reflecting telescope does not absorb the light , just reflects it onto another mirror, wheras the lens of a refracting type absorbs a lot of the light passing through it. It is much easier and cheaper to manufacture a large concave mirror, than a similar sized lens.