Supersonic plasma jets discovered
23 March 2017
Information from ESA's magnetic field Swarm mission has led to the discovery of supersonic plasma jets high up in our atmosphere that can push temperatures up to almost 10,000°C.
Presenting these findings at this week's Swarm Science Meeting in Canada, scientists from the University of Calgary explained how they used measurements from the trio of Swarm satellites to build on what was known about vast sheets of electric current in the upper atmosphere.
The theory that there are huge electric currents, powered by solar wind and guided through the ionosphere by Earth's magnetic field, was postulated more than a century ago by Norwegian scientist Kristian Birkeland.
It wasn't until the 1970s, after the advent of satellites, however, that these 'Birkeland currents' were confirmed by direct measurements in space.