Northern Lights & Southern Lights

Why in news?

According to the National Oceanic and Atmospheric Administration, nearly a dozen states in the northern U.S. could have a chance to observe the northern lights in October 2025.

• Auroras – Also known as the northern lights (aurora borealis) or southern lights (aurora australis) which seen in the Northern Hemisphere and the Southern Hemisphere respectively.
• It is colorful, dynamic, and often visually delicate displays of an intricate dance of particles and magnetism between the Sun and Earth.

Most auroras happen about 97-1,000 kilometres above Earth’s surface.

• Causes for northern & southern lights –
  • The Sun continuously produces an outflow of charged particles into the solar system known as the solar wind.
  • When the solar wind reaches Earth, it can interact with Earth’s magnetic shield, often depositing and accumulating energy there.
  • When this energy is finally released, much of it rains down on our atmosphere, causing northern & southern lights.
• Visibility – They are typically visible during winter months when nights are long and dark.
  • They can be seen at the poles most of the time and also seen in nearby places like Norway, Sweden, Finland, Iceland, Canada, Alaska, and Greenland.
• Colors – The color of an aurora depends on the type of gas that is hit and where that gas is located in the atmosphere (altitude).
  • Red & green light – Ions clashing with oxygen at a high altitude release red light, at a low altitude, they release a green light.
  • Reddish & bluish tinge – Caused by ions interacting with nitrogen.
  • Blue & purple – Ions striking hydrogen and helium atoms.
  • Sometimes, the light emitted by these gases can appear to mix, making the auroras seem purple, pink, or even white.
• Strongest auroras – It occur during periods of high solar activity, such as solar storms or solar flares.

To Know More about Auroras, Click Here

Reference

1. The Hindu | Northern Lights
2. NASA | Auroras