Spacequakes pack punch like earthquakes

William Atkins
Wednesday, 28 July 2010 22:53

Science - Space

The five NASA THEMIS spacecraft have discovered a new type of weather surrounding the Earth. In what is being called the 'spacequake,' a tremor in the magnetic field of the Earth can produce an earthquake out in space.

 

The July 27, 2010 NASA Science News article 'Spacequakes Rumble Near Earth' provides the background to this new discovery on spacequakes by NASA scientists.

NASA launched the constellation of five THEMIS spacecraft on February 17, 2007. THEMIS is short for Time History of Events and Macroscale Interactions during Substorms.

Since then, the five THEMIS spacecraft have been positioned in highly-elliptical orbits about the Earth. They are repositioned during different points in their mission so they can produce the best results for the data they are looking for while in that position.

Average orbital parameters might be so that its nearest point (perigee) on its orbit is about 470 kilometers (290 miles) from Earth's surface, and its furthest point away (apogee) from Earth is approximately 8,700 kilometers (5,400 miles).

And recently, using data from the THEMIS spacecraft scientists have discovered that a type of space weather called a 'spacequake' sometimes occurs in the Earth's magnetosphere.

A magnetosphere is formed around a celestial body, such as Earth, when a stream of charged particles from a star, such as our Sun, interacts with the magnetic field of a planet, such as Earth.

Page two continues.