July 26, 2008
Source of Arctic Northern Lights Revealed
U.S. scientists working with NASA said they've uncovered the source of substorms in space that fuel the explosive energy behind the northern lights.
Vassilis Angelopoulos, a professor at the University of California, Los Angeles and lead investigator of the NASA-funded mission known as THEMIS -- Time History of Events and Macroscale Interactions, said the energy comes from magnetic fields.Our data show clearly and for the first time that magnetic reconnection is the trigger, Angelopoulos said in a statement. Reconnection results in a slingshot acceleration of waves and plasma along magnetic field lines, lighting up the aurora underneath even before the near-Earth space has had a chance to respond. We are providing the evidence that this is happening.
The energy release is responsible for the brightening of the aurora borealis or northern lights. The substorms also wreak havoc on satellites, power grids and communications systems, UCLA said.
The findings are published in the journal Science.