Northern Lights

The Amazing Aurora Borealis

What are the Northern Lights?

The Northern Lights are charged particles that are disconnected from the sun and brought to the polar atmospheres by the Earth's magnetic field.

Why are the Northern Lights called the aurora borealis?

In 1621, Pierre Gassendi named the Northern Lights after the Roman goddess Aurora and boreas, the Greek word for 'the northern wind.' Aurora borealis literally means 'Dawn of the North'. Galileo Galilei was also credited with being one of the first people to call the Northern Lights 'aurora borealis.'

Quote

"Doubly happy, however, is the man whom lofty mountain tops are within reach, for the lights that shine there illumine all that lies below." - John Muir

Why Do The Northern Lights Appear in Our Sky?

The aurora borealis are made of tons of tiny particles from the sun, a mixture of protons and electrons called plasma (and no, not the type of plasma in blood). These are often released in solar flares. The plasma comes flying towards the Earth, and our magnetic field pulls the current of particles toward the polar atmospheres (North and South Poles). The plasma collides with different gases and creates the colors that we see in the sky.

The Colors of the Northern Lights

The colors of the aurora borealis depends on several variables: how high up in the sky they are, the type of gases that are colliding with the particles, and how energized the gases' atoms are. For example, if you see green in the light display (which is one of the most common colors) the height would be at about 120-180 km (about 75-110 miles), and the gas colliding with the plasma would be atomic oxygen, at a normal energy 'speed,' if that makes sense. Red is caused by both oxygen and nitrogen. These can occur either very low in the sky (90-100km/55-62mi) or higher than the 180km of the green. There are also blues and violets that are caused by ionized nitrogen. These occurs at altitudes of below 120km.