Three big discoveries of Northern Lights

William Atkins
Wednesday, 12 December 2007 20:53

Science - Space

The NASA THEMIS spacecraft—after only eight months in active operation—has made three important discoveries about “why” the aurora borealis, commonly called the Northern Lights, suddenly appears very bright and “where” it gets all of its  energy.                 

The aurora borealis is named after the Roman goddess of the dawn, Aurora, and the Greek name for the north wind, Boreas. The greenish, sometimes reddish, glow is visible in the northern sky of the Northern Hemisphere, most often from March-to-April and from September-to-October.

There are five satellites comprising the THEMIS (Time History of Events and Macroscale Interactions during Substorms) mission, which was launched by NASA on February 17, 2007, from Cape Canaveral Air Force Station, Launch Complex 17.

In addition, in Greek mythology, Themis was one of the twelve offspring of Gaia and Uranus.

Each satellites carries a full compliment of instruments to allow it to study energy releases from Earth’s magnetosphere (what are called substorms).

These substorms cause the auroras, located near the north and south poles of the Earth, to intensify in appearance.

What THEMIS Found ....