Enceladus Geysers Mask the Length of Saturn's Day 22 Mar 2007 In
a David and Goliath story of Saturnian proportions, the little
moon Enceladus is weighing down giant Saturn's magnetic field so
much that the field is rotating slower than the planet. This
phenomenon makes it nearly impossible to measure the length of
the Saturn day using techniques that work at the other giant
planets. "No one could have predicted that the little moon
Enceladus would have such an influence on the radio technique
that has been used for years to determine the length of the
Saturn day," said Dr. Don Gurnett of the University of Iowa,
Iowa City. Gurnett is the principal investigator on the radio
and plasma wave science experiment onboard NASA's Cassini
spacecraft. The radio technique measures the rotation of the
planet by taking its radio pulse rate--the rhythm of natural
radio signals from the planet. A new study of Cassini data
reported this week in the online version of the journal Science
determined that Saturn's magnetic field