Question

Explain why planets do not twinkle at night. [2 MARKS]

Answer 1

Each point: 1 Mark

1. The planets are much closer to earth and are thus seen as extended sources.
2. If we consider a planet as a collection of a large number of point-sized sources of light, the total variation in the amount of light entering our eye from all the individual point-sized sources will average out to zero, thereby nullifying the twinkling effect.