Observing a dayside proton auroral spot
Date: 12 May 2003
Copyright: Geophysical Research Letters
This illustration shows the configuration of spacecraft and the Earth at the time that the observations were made of a breakthrough of protons. On 18 March 2002, NASA's IMAGE was closer to the Earth and observing an aurora that contained a dayside proton auroral spot (see bottom left picture). At the same time, ESA's Cluster quartet then passed overhead returning proton data (see top left graph) that showed a magnetic reconnection was taking place and that protons were leaking through Earth's magnetic shield. These protons were then being funnelled into Earth's atmosphere along the magnetic field to form the spot.
Last Update: 1 September 2019