Planetary science: Saturn’s magnetosphere gets the Cassini treatment

Saturn’s magnetosphere overturns in a way similar to that of Jupiter.
It’s known that cold, dense plasma from Jupiter’s inner magnetosphere is flung outward and replaced by hotter plasma from the outer magnetosphere — a little like convection in a pot of liquid. But whether the same is true for Saturn’s magnetosphere has been a matter of debate, given that Saturn’s magnetosphere shares other features with that of Earth. William Lewis and colleagues now study the cold plasma next to hot, inward-moving plasma in its magnetosphere to show that this cold plasma is outward bound, so Saturn’s magnetosphere does indeed have similar overturning to Jupiter’s — a discovery made possible by Cassini’s plasma spectrometer.
CONTACTWilliam Lewis (Southwest Research Institute, San Antonio, TX, USA)
Tel: +1 210 522 5651; E-mail: wlewis@swri.edu