The thermosphere is a layer of the earth's atmosphere directly above the mesosphere and below the exosphere. It extends 56 miles to about 621 miles above the earth.
It is in the thermosphere that auroras are seen. An aurora is luminous atmospheric phenomenon appearing as streamers or bands of light sometimes visible in the night sky in northern or southern regions of the earth. It is thought to be caused by charged particles from the sun entering the earth's magnetic field and stimulating molecules in the atmosphere.
