THE mysterious electrical circuitry behind the northern lights has been
revealed for the first time by a team of satellites travelling through the upper
reaches of an aurora. Goran Marklund of the Royal Institute of Technology in
Stockholm, Sweden, and co-workers got their data from the European Space
Agency’s four Cluster satellites. It shows electrons draining out into space
from the ionosphere—the charged part of the atmosphere
(Nature, vol 414, p 724).
Patrick Newell of Johns Hopkins University in Laurel, Maryland, says once the
ionosphere is drained, huge electric fields build up. Eventually electrons are
catapulted down towards…
