|
February 2, 1998:
Triple Eclipse Dazzles Astronomers
As sky-watchers on Earth gear up to watch a rare total
solar eclipse at the end of this month (February 26, visible
in a 73-mile-wide band including places like Aruba,
Montserrat, northern Colombia and eastern Panama - visible
as a partial eclipse in the eastern U.S.), astronomers at
the University of Arizona and New Mexico State University
have caught sight of another elusive astronomical
phenomenon: a triple eclipse of Jupiter by three of the
giant planet's moons.
Jupiter has 16 moons, so eclipses, caused by moons
casting their shadows on the planet's surface, are a fairly
common occurrence there. However, three simultaneous
eclipses near one another only occur once or twice each
century.
The following images were taken over a two hour period on
November 10, 1997, and were released to the public this
week. All images are courtesy of Erich Karkoscha, University
of Arizona Lunar and Planetary Lab, and Scott Murrell,
Department of Astronomy, New Mexico State University.
Watch the shadows move across
Jupiter!
|
1. The black dot near the left edge of the
planet's disk is the shadow of Callisto. The
yellow-orange dot just slightly above the shadow is
the satellite Io.
|
|
|
2. The shadow of Ganymede appears at the left
side of Jupiter's disk, while Callisto's shadow and
Io move across the face of the planet.
|
|
|
3. Io's shadow appears on the left side of the
Jupiter. The shadows of the other two satelites,
and the yellow-orange Io, continue to move across
the face of the planet.
|
|
|
4. Because the satellites are at different
heights above Jupiter's surface, their shadows move
at diferent speeds in relation to one another. The
shadows of the moons begin to catch up to one
another.
|
|
|
5. The shadow of Io, moving more quickly than
the other shadows, has caught up and merged with
the shadow of Ganymede. Callisto's shadow is
slightly below and to the right of the shadows of
the other moons. Io is visible as a light dot off
the right edge of Jupiter.
|
|
All images courtesy of Erich Karkoscha, University
of Arizona Lunar and Planetary Lab, and Scott Murrell,
Department of Astronomy, New Mexico State University.
|
