What Are The Northern Lights (Aurora Borealis)?
The Northern Lights in Iceland, sometimes referred to as Aurora Borealis, is a magical display of light in the sky that can only be seen in wintertime (September - April, when it's dark). It's scientific and a little technical but basically they are caused by the sun. The sun is a huge ball of hydrogen and other gases which fuse away in space. The sun has storms called solar storms.
Imagine the sun like a huge ball of plasma. All the plasma swirling around within the sun makes a huge magnetic field that's under a lot of pressure. Sometimes the lines of force within these magnetic fields meet and leave the sun’s surface as hot gases and charged particles, and enter the earth’s atmosphere (solar flare). Once these flares reach Earth (solar winds) they can be extremely dangerous but our planet produces a magnetic field to help protect us (earth magnetosphere).
Earth’s magnetic field has two weak spots, the North and South Poles, which means a small amount of the sun’s charged particles can reach Earth’s atmosphere. These solar winds collide with the oxygen and nitrogen atoms of Earth's atmosphere, this enhances their energy. The atoms release this newfound energy in the form of particles of light (photons) and this light is known as the Aurora or Northern Lights.
The colours of light you see depend on the different types of gas particles being released and colliding with the charged particles entering the earth’s hemisphere, i.e. Oxygen = green, Nitrogen = blue, red. Here in Iceland we mostly see a green light but it's possible to see blue or purple at the edge of the green. Last September was an amazing display where we saw a hint of pink, purple and red - it was as magical as it sounds.