Northern Lights (Aurora Borealis)

Overview

• Polar lights (aurora polaris): Includes both northern lights (aurora borealis) and southern lights (aurora australis).
• Location: Occur above the magnetic poles in the northern and southern hemispheres.
• Aurora borealis: Known as "Dawn of the North".

Causes

• The Sun emits heat, light, and other energy particles.
• Earth's invisible magnetic field generally protects us from these emissions.
• During a solar storm (coronal mass ejection), the Sun releases electrified gas at high speeds.
• Some particles penetrate the Earth's magnetic field, reaching the atmosphere at the poles.
• Interaction with atmospheric gas particles creates aurora displays.

Aurora Characteristics

• Colours: Light green and pink are most common; other colours include purple, red, yellow, and blue.

Viewing the Northern Lights

• Optimal Time: Winter nights with clear skies.
• Frequency: The best displays are said to occur every 11 years.
• Popular Locations:
  • Canada: Yukon, Northwest Territories, Nunavut.
  • Alaska, Greenland, Iceland, Sweden, Norway, Finland.
• Auroras on Other Planets: Notably seen in Jupiter and Saturn.

Sources

• CBC Kids - Northern Lights
• NASA Space Place - Aurora
• Northern Lights Centre
• The Canadian Encyclopedia - Northern Lights
• Library of Congress - Northern Lights

Images

• Slide 2: Photo by Tobias Bjorkli from Pexels
• Slide 4: Image source NASA Space Place - Aurora
• Slide 5: Pictures by Pixabay and Frans Van Heerden from Pexels