JPL: Hot Plasma Explosions Inflate Saturn's Magnetic Field
Posted: Tue Dec 14, 2010 11:28 pm
Hot Plasma Explosions Inflate Saturn's Magnetic Field
NASA JPL Cassini | 14 Dec 2010
NASA JPL Cassini | 14 Dec 2010
A new analysis based on data from NASA's Cassini spacecraft finds a causal link between mysterious, periodic signals from Saturn's magnetic field and explosions of hot ionized gas, known as plasma, around the planet.Artist Concept of Particle Population in Saturn's Magnetosphere
This is an artist's concept of the Saturnian plasma sheet based on data
from Cassini magnetospheric imaging instrument. It shows Saturn's
embedded "ring current," an invisible ring of energetic ions trapped
in the planet's magnetic field. (Credit: NASA/JPL/JHUAPL)
Scientists have found that enormous clouds of plasma periodically bloom around Saturn and move around the planet like an unbalanced load of laundry on spin cycle. The movement of this hot plasma produces a repeating signature "thump" in measurements of Saturn's rotating magnetic environment and helps to illustrate why scientists have had such a difficult time measuring the length of a day on Saturn.
"This is a breakthrough that may point us to the origin of the mysteriously changing periodicities that cloud the true rotation period of Saturn," said Pontus Brandt, the lead author on the paper and a Cassini team scientist based at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The big question now is why these explosions occur periodically."
The data show how plasma injections, electrical currents and Saturn's magnetic field -- phenomena that are invisible to the human eye -- are partners in an intricate choreography. Periodic plasma explosions form islands of pressure that rotate around Saturn. The islands of pressure "inflate" the magnetic field.
A new animation showing the linked behavior is available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .