... The ring current (e.g., Frank, 1967) consists of geomagnetically trapped 10 - 200 keV ions (mainly H + , He + , and O + ) and electrons that drift azimuthally around the Earth at radial distances of about 2-7 Re (Earth radii), overlapping the radiation belt region. ... This index can be used to monitor the development of geomagnetic storm (see also geomagnetic activity ), as the main signature (actually definition) of the storm main phase is the build-up of an enhanced ring current. ... Res., ...
... A Teacher's Introduction to the Earth's Magnetosphere . ... Exploration" as a Classroom Resource . A basic chronology of key dates in the exploration of the magnetosphere. ... Radiation Belts. The Sun and the Solar Wind. ... Close-Up of the Aurora. ... The Polar Aurora . ... 10H. History: 1910--Einstein introduces "adiabatic invariants". 10a. Particle Drift in Space (optional) . ... 25H. History: 1903--Birkeland observes the electric currents of the polar aurora. 25a. The Triad Spacecraft . ...
Ice Volcanoes Reshape Europa's Chaotic Surface . Ice-spewing volcanoes and the grinding and tearing of tectonic plates have reshaped the chaotic surface of Jupiter's frozen moon Europa, images from NASA's Galileo spacecraft reveal. ... Although the images do not show currently active ice volcanoes or geysers, they do reveal flows of material on the surface that probably originated from them, said Galileo imaging team member Dr. Ronald Greeley of Arizona State University, Tempe. ... Europa . ...