Auroras
WHAT ARE AURORAS?
- Aurora is the luminous glow in the upper atmosphere of the Earth.
- It is produced by charged particles (solar wind) descending from the planet’s magnetosphere.
HOW AURORAS ARE FORMED?
- It is formed by collisions between fast-moving electrons from space with the O2 and N2 molecular electrons in Earth’s upper atmosphere.
- With the bombardment of large number of electrons, the O2 and N2 molecules emit enough light.
WHAT ARE TYPES OF AURORAS?
- Aurora Borealis (Northern lights)
- Aurora Australis (Southern lights)
WHERE DOES AURORAS OCCUR?
- At high northern and southern latitudes.
- Less frequent at mid-latitudes, and seldom seen near the equator.
WHY DO AURORAS COME IN DIFFERENT COLORS AND SHAPES?
- The color depends on gas is being excited by the electrons.
- It also depends upon how fast the electrons are moving.
- High energy electrons cause oxygen to emit green light.
- Low energy electrons cause a red light.
- Nitrogen generally gives blue light.