Question: What are auroras? Explain their formation and significance for scientific research.
Answer: Auroras are bright colourful lights that are visible in night sky of certain planets having a well developed atmosphere. These phenomenons are quite common on Earth especially near the polar areas.
Formation of auroras
- Auroras occur in those planets that have an atmosphere as well as magnetic field.
- The solar particles ejected from the sun travel towards planets, intending to reach the planetary surface.
- These particles are not allowed by the magnetic field to enter atmosphere by diverting them away.
- In some case when magnetic field is not strong enough or non-continuous, these particles are able to reach atmosphere.
- Solar particles then interact with atmospheric gases and excite to form colourful lights in the sky.
Auroras on Earth
- Auroras on earth are formed near northern and southern pole areas due to weakened magnetic field in these regions.
- The northern auroras are known as northern lights or aurora borealis. The southern auroras are known as southern lights or aurora australis.
Significance of auroras
- Study magnetic field
Auroras formation only in selected areas indicates that magnetic field of a planet is intact as it has been successful in diverting majority of solar particles.
- Study of atmosphere
Study of auroras can also help in identifying composition of a planet’s atmosphere as every light wavelength is dependent on its chemical composition.