Aurora Borealis: What are Northern and Southern lights? Why do they occur?

Why in the news?

• In a rare event, the night sky over Hanle village in Ladakh was illuminated by the northern lights or aurora borealis.
  • Concurrently, the southern lights, or aurora australis, were observed in New Zealand and Australia.

What are Auroras?

• Auroras are natural light displays that appear as bright, swirling curtains in the night sky.
• They are typically seen near the Poles but can occasionally be observed at lower latitudes.
• These lights can display a range of colors, including blue, red, yellow, green, and orange, due to the interaction of solar particles with different gases in the Earth’s atmosphere.
• The phenomenon is known as:

1. Aurora borealis in Northern Hemisphere and
2. Aurora australis in Southern Hemisphere

What causes Auroras?

• Interaction with Earth’s Magnetic Field: As the solar wind approaches Earth, it interacts with the planet’s magnetic field, causing some charged particles to enter the atmosphere near the poles.
• Interaction with Gases: These particles interact with gases in the upper atmosphere, producing colourful flashes of light. Collision with oxygen produces green light, while interaction with nitrogen results in shades of blue and purple.

Impact on Tech Infrastructure 

• Auroras can pose challenges to space-dependent technologies and operations.
• Disruptions in Global Positioning Systems (GPS), radio communications, flight operations, power grids, and space exploration endeavors may occur during such events.