If you have ever been to the far north or just lucky enough to be at the right place at the right time, you might have seen the northern lights.
The northern lights are also known as the aurora borealis, a name coined by the famous astrologer Galileo in 1619 to describe the unusual display of lights, which is most easily seen in the night sky. In Latin, aurora borealis means “morning light coming from the north.” These lights are formed when electrically charged particles emitted by the sun come in contact with gaseous particles in the Earth’s atmosphere. The kinds of these particles and their altitude in the atmosphere plays an important role in the color of the light and the size and shape of the image. When the solar winds come in contact with oxygen particles, the lights are usually green, yellow or orange in color. When the solar particles collide with nitrogen, the lights have a bluish or purple color. As particles and lights intermix, the colors can mix together, giving a pinkish, yellow–green color. This light show can take on many forms, from flickering lights to arcs, patches or large blobs in the sky.
When the solar winds reach the Earth, they come in contact with the Earth’s magnetic field. Where the field is strongest, the particles are deflected. The polar regions have weak magnetic fields and will allow the particles to enter the atmosphere. The areas that absorb the most particles are known as the aurora oval. When viewing the northern lights from the aurora oval the lights appear to be overhead. Sometimes spectators can hear a distinct hissing sound as the charged particles collide.
The northern lights appear to be off in the distance when viewing them from more southerly locations. The eerie lights emitted at the South Pole are known as the aurora austrailus, and they can be most easily seen around Antarctica, Chile and Australia.
The northern lights are best seen in fall and winter.
For more information on the FCFCDB, visit frederick.forestryboard.org.