The Night Sky



What is the horizon?

The horizon is the limit of the observer’s field of vision from any point on the Earth’s surface. It is the maximum distance to which one can see across the horizon appears as a distant circular boundary surrounding the observer. The horizon recedes as one goes higher above the surface of the Earth i.e. the field of view increases.






How do meteors shine?

Meteors shine when they heat up and burn due to air friction while falling through the Earth’s atmosphere.







How do comets shine?

When a comet approaches the Sun, the heat from the Sun vaporizes part of the material in the comet, causing it to glow.






Why do stars twinkle?

Distortion of star light by Earth’s atmosphere makes the stars apparently twinkle.

Do stars twinkle uniformly in all parts of the night sky?

No. Stars twinkle more when they are near the horizon, since their light has to pass obliquely through a thicker layer of the Earth’s atmosphere which has a greater distortion effect.