The BEST shape for the cross-section of a simple astronomical mirror to have in order to produce the sharpest images of very distant objects at its prime focus is:
A) parabolic.
B) elliptical.
C) perfectly flat and smooth.
D) spherical.

Question

Quizplus · Accepted Answer

A parabolic mirror is the ideal shape for producing sharp images at the prime focus. This is because it can focus all the light that comes in from a distant object to a single point, allowing for minimal distortion and the clearest possible image. Spherical mirrors, on the other hand, suffer from spherical aberration, which results in out-of-focus and distorted images. Elliptical mirrors can produce sharper images than spherical mirrors, but they still suffer from some distortion. A flat mirror would be unable to focus light at all, since it would reflect light away in all directions rather than concentrating it at a single point. Therefore, A) parabolic is the best choice for producing sharp images at the prime focus of an astronomical mirror.

The BEST Shape for the Cross-Section of a Simple Astronomical