December 16, 2004
Polarized Light from Jupiter's Poles
January 23, 2001
These frames taken by NASA's Cassini spacecraft show that infrared light
from Jupiter's north and south poles is polarized, which indicates that
the size of cloud aerosol particles in those regions is likely smaller
than the particles found in clouds near the equator.
Cassini's wide-angle camera took these images with a near-infrared filter
useful for seeing methane, combined with filters that sense whether the
light is polarized. The pole appears bright in one image and dark in the
other, showing that the light from those regions is polarized. Polarized
light is most readily scattered by aerosols. These images indicate that
the aerosol particles at Jupiter's poles are small and likely consist of
aggregates of even smaller particles, whereas the particles at the equator
and covering the Great Red Spot are larger. Images like these will allow
scientists to ascertain the distribution, size and shape of aerosols, and
consequently, the distribution of heat, in Jupiter's atmosphere.
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 the Cassini
mission for NASA's Office of Space Science, Washington, D.C.
Credit: NASA/JPL/University of Arizona
For higher resolution, click here.