HUBBLE SPOTS RARE TRIPLE ECLIPSE ON JUPITER (STScI-PRC04-30)

FOR RELEASE: 12:01 am (EST) November 4, 2004

PHOTO NO.: STScI-PRC04-30

HUBBLE SPOTS RARE TRIPLE ECLIPSE ON JUPITER

At first glance, Jupiter looks like it has a mild case of the measles.
Five spots -- one colored white, one blue, and three black -- are
scattered across the upper half of the planet. Closer inspection by
NASA's Hubble Space Telescope reveals that these spots are actually a
rare alignment of three of Jupiter's largest moons -- Io, Ganymede,
and Callisto -- across the planet's face. In this image, the telltale
signatures of this alignment are the shadows [the three black circles]
cast by the moons. Io's shadow is located just above center and to the
left; Ganymede's on the planet's left edge; and Callisto's near the
right edge. Only two of the moons, however, are visible in this image.
Io is the white circle in the center of the image, and Ganymede is the
blue circle at upper right. Callisto is out of the image and to the
right.

On Earth, we witness a solar eclipse when our Moon's shadow sweeps
across our planet's face as it passes in front of our Sun. Jupiter,
however, has four moons roughly the same size as Earth's Moon. The
shadows of three of them occasionally sweep simultaneously across
Jupiter. The image was taken March 28, 2004, with Hubble's Near
Infrared Camera and Multi-Object Spectrometer.

Credit: NASA, ESA, and Erich Karkoschka (University of Arizona)

To see and read more, please visit:
http://hubblesite.org/news/2004/30

For additional information, contact: Erich Karkoschka, Univ. of Arizona,
Lunar and Planetary Lab, Tucson, AZ 85721, (phone) 520-621-3994,
(e-mail)

The Space Telescope Science Institute (STScI) is operated by
the Association of Universities for Research in Astronomy, Inc.
(AURA), for NASA, under contract with the Goddard Space Flight
Center, Greenbelt, MD. The Hubble Space Telescope is a project
of international cooperation between NASA and the European Space
Agency (ESA).

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