Aug. 1, 2012 Exploiting a favourable configuration of ESA's
Cluster mission spacecraft, scientists have detected and
characterised lower hybrid drift waves, a special kind of plasma
waves that develop in thin boundaries both in space and in the
laboratory. The measurement of fundamental properties of these
waves was possible when two of the spacecraft were flying very
close to one another in the tail of Earth's magnetosphere. With
wavelengths of about 60 km, these waves appear to play an
important role in the dynamics of electrons and in the transfer
of energy between different layers of plasma in the
magnetosphere. Like all planets with a magnetic field, Earth has
a protective shield against the solar wind, the stream of
charged particles released continuously by the Sun. This bullet-
shaped bubble, called the magnetosphere, is forged by the
interplay between the solar wind and our planet's magnetic field
and is composed of plasma, a state of matter that consists of
charged particles and ions rather than atom