Patterson, Romaine, and Patrick Hinds.The Whole
World Was Watching: Living in the Light of Matthew
Shepard. New York: Advocate Books, 2005.
Jessie Bishop Powell
See also Clinton, Bill; Crime; Hate crimes; Homo-
sexuality and gay rights; Transgender community.
Shoemaker-Levy 9 comet
The Event A comet strikes the planet Jupiter
Date July 16-July 22, 1994
The impact of the Shoemaker-Levy 9 comet with Jupiter pro-
vided the first direct observation of a collision between two
objects from the solar system.
On March 24, 1993, at the Mount Palomar
Observatory in California, astronomers
Carolyn and Eugene Merle Shoemaker and
David Levy codiscovered Comet Shoemaker-
Levy 9. The comet was unusual in that it or-
bited the planet Jupiter and not the Sun. Sev-
eral professional astronomers confirmed
this discovery at roughly the same time.
The Shoemaker-Levy 9 comet consisted
of multiple objects that traveled in the same
path. It orbited Jupiter approximately every
two years and had passed close to Jupiter on
July 7, 1992. This close pass subjected the
comet to Jupiter’s intense gravitational pull,
which probably fragmented the original
comet into the multipart object observed in
- The tight orbit of the comet around Ju-
piter strongly suggested that it would collide
with Jupiter on its next pass.
On July 16, 1994, at 20:15 coordinated uni-
versal time (UTC), the first fragment of the
comet struck the southern hemisphere of Ju-
piter at a speed of about thirty-seven miles per
second. The comet struck the side of Jupiter
hidden from Earth, but the rapid rotation of
Jupiter brought the impact sites into view
only a few minutes after the collisions. Since
Jupiter is a gas giant and not a solid planet,
the comet passed into Jupiter’s atmosphere
and was eventually crushed by the enormous
pressure. This massive release of energy gen-
erated an intense fireball and a plume of
cometary debris eighteen hundred miles high. The
dark spot that formed soon after the impact mea-
sured half the diameter of Earth. Over the following
six days, twenty more objects collided with Jupiter.
Atmospheric gases expelled in the plumes con-
firmed the existence of Jupiter’s outer atmospheric
cloud layer of ammonia (NH 3 ) and second, lower
cloud layer of ammonium hydrosulfide (NH 4 SH).
Scientists postulated a third water vapor cloud
layer, but the amount of water vapor in the plumes
was less than expected, which suggests that the
water vapor layer is thinner than previously postu-
lated. Far more sulfur was ejected than would be
expected for a comet, which shows that Jupiter’s
lower atmosphere contains respectable quantities
of sulfur.770 Shoemaker-Levy 9 comet The Nineties in America
An ultraviolet image of Jupiter taken by the Hubble Space Telescope on July
21, 1994, shows a number of fragments from Comet Shoemaker-Levy 9 that
struck the planet’s southern hemisphere. These fragments were embedded in
clouds of debris, which appear very dark in the ultraviolet photo, as dust ab-
sorbs light.(NASA/JPL)