The International Outer Planet Watch
This is the new webpage for the IOPW program. You will
hereafter find links to the former webpages of the program and each
Please send us an email (contact) if you would like to post
more information about your research and observations.
The International Outer Planet Watch is a program for the encouragement
and coordination of the study of temporal variations in the Outer
Planets. The IOPW coordinates 24-hour coverage of outer planet
phenomena when such coverage is needed. It provides a mechanism for the
rapid sharing of information to the community of scientists studying
the outer planets.
Scientists working fir the progam belong to several discpines, among
which 3 are closely related. This is the "Aurora, Magnetosphere, nad Io
Torus" part of the
The Magnetosphere discipline is closely related to the Aurora
discipline. The objective is to study the structure of planetary
magnetospheres and their interaction with the solar wind.
The auroral discipline is specifically concerned with the study of
aurorae on Jupiter. "The aurorae on Jupiter are of interest because
they allow us to infer the nature of the precipitating energetic
particles which cause the auroral radiation. The study of aurorae
allows the testing of models of the planetary magnetic field. It
permits us to determine the rate of energy deposition from
magnetospheric sources. By determining where the aurorae occur, one can
ascertain the magnetospheric source regions of the particles and
possible causative mechanisms. In particular, it is of significant
interest to determine the causes for the differences between the
northern and southern aurorae. Finally, particle precipitation near the
magnetic poles induces unique chemistry that is important for
understanding some aspects of aerosol formation."
Russell et al. [external link] (1990)
Discipline Leader: Jack Connerney, Solar System Exploration Division at NASA's Goddard Space Flight Center
The Io torus is a doughnut-shaped ring of gas surrounding Jupiter. The
gas originates from the many volcanoes on Io, Jupiter's closest large
satellite. The volcanoes on Io spew out sulfur and sulfur dioxide at a
rate of 1,000 kg/sec.
These particles are ejected into space and are stripped of their
electrons (or ionized). The particles (ions) then become trapped in
Jupiter's magnetic field. Because the field rotates with the planet,
the particles make a complete circle around the planet every ten hours,
the rotational period of Jupiter.
As Io circles around Jupiter and through the plasma torus, an enormous
electrical current flows between them. Approximately 2 trillion watts
of power is generated. The current follows the magnetic field lines to
Jupiter's surface where it creates lightning in the upper atmosphere.