The Sun is visible to us about 2 minutes before the actual sunrise and about 2 minutes after the actual sunset due to atmospheric refraction. Atmospheric refraction causes the Sun’s light to bend, allowing us to see the Sun even ...

Considering a planet as a collection of numerous point-sized sources of light, the total variation in the amount of light entering our eyes from all these individual sources averages out to zero. This averaging effect occurs due to the proximity ...

The planets being much closer to Earth are seen as extended sources. 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 eyes ...

The planets don’t twinkle because they are much closer to Earth and are seen as extended sources of light. Unlike stars, which are viewed as point-sized sources, planets can be considered as collections of a large number of point-sized sources.

Both the twinkling of stars and the wavering in hot air involve atmospheric refraction, but they occur on different scales. Twinkling is caused by the continuous refraction of starlight through the Earth’s atmosphere, while the local wavering is a result ...