Comet Shoemaker-Levy Information

Comet Shoemaker-Levy 9, torn into pieces as a result of a
close approach to Jupiter in July 1992, will collide with
Jupiter during the third week of July 1994. Of tremendous
scientific importance, the impacts of the cometary fragments
will release more energy into Jupiter's atmosphere than that
of the world's combined nuclear arsenals. Because the impacts
will occur on the night side of Jupiter, the explosions will
not be directly observable from Earth. However, professional
and amateur astronomers may observe the impact light flashes
reflected off the inner satellites of Jupiter. Any lasting
effects on Jupiter, such as atmospheric clouds, ejecta plumes,
or seismic thermal disturbances, may be observable an hour or
so later when the rotation of Jupiter brings the impact sites
into Earth's view. 

Analysis of high-resolution images of the comet taken by the
NASA's Hubble Space Telescope in July 1993 suggests that the
major cometary fragments range in size from one to a few
kilometers. The large fragments are embedded in a cloud of
debris with material ranging in size from boulder-sized to
microscopic particles. Although comet-like outgassing of the
fragments has not been observed, the fragile nature of the
object suggests that it is indeed a comet rather than a more
compact asteroid. 

Comet Shoemaker-Levy 9 was the ninth short-periodic comet
discovered by Eugene and Carolyn Shoemaker and David Levy. It
was first detected on a photograph taken on the night of March
24, 1993 with the 0.4-meter Schmidt telescope on Palomar
Mountain in California. Subsequent observations were
forthcoming from observers at the University of Hawaii, the
Spacewatch telescope on Kitt Peak in Arizona and McDonald
Observatory in Texas. These observations were used to
demonstrate that the comet was in orbit about Jupiter, and had
made a very close approach (within 1.4 Jupiter radii from
Jupiter's center) on July 7, 1992. During this close approach,
the unequal Jupiter gravitational attractions on the comet's
near and far sides broke apart the fragile object. The
disruption of a comet into multiple fragments is an unusual
event, the capture of a comet into an orbit about Jupiter is
even more unusual, and the collision of a large comet with a
planet is an extraordinary, millennial event.