What do you believe causes those mysterious "Northern Lights" ?

• "Scientists think they have discovered the energy source of the spectacular color displays seen in the northern lights. New data from NASA's Themis mission, a quintet of satellites launched this winter, found the energy comes from a stream of charged particles from the sun flowing like a current through twisted bundles of magnetic fields connecting Earth's upper atmosphere to the sun." http://news.yahoo.com/s/ap/20071211/ap_on_sc/northern_lights 'Images Now Show a Circular Opening at the North Pole!. Something that all Hollow Earth Theorists have been waiting for. ... http://www.burlingtonnews.net/hollowearth.html Strange Map: Inside the Hollow Earth http://strangemaps.wordpress.com/2007/03/01/85-inside-the-hollow-earth/ So is it energy from our Sun or enery from within Earth leaking out of a northern opening ?

• Answer:

  Auroras are produced by the collision of charged particles, mostly electrons but also protons and heavier particles, from the magnetosphere, with atoms and molecules of the Earth's upper atmosphere (at altitudes above 80 km). The particles have energies from 1 - 100 keV. Most originate from the sun and arrive at the vicinity of earth in the relatively low energy solar wind. When the trapped magnetic field of the solar wind is favourably oriented (principally southwards) it reconnects with that of the earth and solar particles then enter the magnetosphere and are swept to the magnetotail. Further magnetic reconnection accelerates the particles towards earth. The collisions in the atmosphere electronically excite atoms and molecules in the upper atmosphere. The excitation energy can be lost by light emission or collisions. Most aurorae are green and red emission from atomic oxygen. Molecular nitrogen and nitrogen ions produce some low level red and very high blue/violet aurorae.