Bizarre New Sounds of Jupiter from NASA

December 30, 2000

First Color Jupiter image from Cassini NASA's Cassini spacecraft, as it approached Jupiter, detected waves in the thin gas of charged particles that fills the space between the Sun and its planets. The waves are in low radio frequencies, which have been converted to sound waves to make the patterns audible.

Click to Listen

The audio clip, like a previous clip returned by Cassini, comes
from waves that were derived from an interaction of the magnetic
field that surrounds Jupiter and the solar wind of particles
speeding away from the Sun.

The oscillations discernible in the audio file are from ion-
acoustic waves, which result from electrons moving in non-random
patterns driven by a flow of energy. In this case, the energy
flow probably comes from the heat of Jupiter's bow shock. The bow
shock is similar to a sonic boom from a supersonic jet flying
through Earth's atmosphere, except that the bow shock is caused
by the supersonic solar wind being diverted around Jupiter's
magnetic field. The shock is a place where the solar wind is
heated, slowed and deflected by the magnetic field surrounding
Jupiter. Cassini has not reached the bow shock, but the shock is
probably the source of energy driving the waves that are reaching
the spacecraft.

Cassini is a cooperative project of NASA, the European Space Agency and
the Italian Space Agency. The Jet Propulsion Laboratory, a division of the
California Institute of Technology in Pasadena, manages Cassini for NASA's
Office of Space Science, Washington, D.C.

Contact Information:

Prof. Donald A. Gurnett,

or Dr. William Kurth,

Department of Physics and Astronomy

University of Iowa

Van Allen Hall

Iowa City, IA 52242


Additional information about Cassini is available online at:

The Cassini spacecraft is scheduled to arrive at Saturn in July 2004 to
begin a four-year exploration of the ringed planet and its moons. The
Cassini mission is managed by NASA's Jet Propulsion Laboratory in Pasadena,
Calif., for NASA's Office of Space Science, Washington, D.C. JPL is a
division of the California Institute of Technology in Pasadena.

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