Aurora
Also called: Aurora borealis, aurora australis, northern lights, southern lights, Northern and southern lights · Topic: Atmosphere: Composition, Structure and Elements of Weather · NCERT: Class 9, Ch 3 "Atmosphere and Climate"
Meaning
An aurora is a glowing curtain of coloured light in the night sky, seen mostly near the poles. The Sun sends out a stream of charged particles called the solar wind. The Earth's magnetic field steers these particles towards the magnetic poles. There they strike gases high in the thermosphere and make them glow: oxygen gives green and red, and nitrogen gives blue and purple. The aurora is called the Aurora Borealis (northern lights) in the north and the Aurora Australis (southern lights) in the south.
Example
During the strong geomagnetic storm of May 2024, an aurora was seen from Hanle in Ladakh, far from the North Pole. This is rare, because India lies at low latitudes, a long way from the magnetic poles.
Don't confuse with
- Stratosphere: auroras do not form in the stratosphere (about 12–50 km). They form much higher, in the thermosphere.