In April 1991 the space shuttle Discovery photographed this
display of the aurora australis, or southern lights, over the
Antarctic region. From above, you can see the magnetic field
lines, a series of vortices in the Earth's magnetic field, along
which electrons and protons move as they burst into the
atmosphere. When space weather pours energy towards Earth and
energizes its magnetic field, particles flow and collect at both
ends of these field lines, culminating in 2,500-mile-wide rings
encircling each pole.