taken by Mats Lindgren at the European Southern
Observatory in Chile.
Image taken on March 28, 1993, just 4 days
after it was discovered.
On the night of March 24, 1993, Eugene and Carolyn
Shoemaker and David Levy discovered a strange
looking comet from a photograph taken from the
0.4 meter Schmidt telescope in Palomar Observatory
in Califonia. The comet was named Comet Shoemaker-Levy
9 after the discoverers, the ninth comet discovered
by this team. The comet was very elongated, and
it turned out that comet had been pulled apart
due to tidal forces from an extremely close flyby
of Jupiter on July 8, 1992. Twenty-one separate
fragments were eventually identified. By April
5, 1993, enough observations of the comet have
been made to better define the comet's orbit,
and it was surprisingly found to be in orbit around
Jupiter. By May 25, additional observations helped
refined the orbit further, and a exciting new
development came forth: Comet Shoemaker-Levy 9
could possibly impact Jupiter in July 1994! By
June 1993, the comet's orbit was well determined
and the impacts into Jupiter would definitely
image taken in May 1994. The fragments were
named from the letters of the alphabet in
the order they would impact on Jupiter.
With one year's advance notice, astonomers and
observatories made plans to observe this unique
event. This would mark the first time that a collision
between two solar system bodies would be observed.
Most astronomers downplayed the event to the public,
mainly due to past disappointments with a couple
of expected bright comets in the previous two
decades that did not live up to expectations.
Astronomers noted that the impacts were very unusual,
but they warned that the effects of the impacts
of the comet would probably not be visible to
Earth except by the largest telescopes. Also,
the impacts would occur on the night side of Jupiter,
out of direct view from Earth. The 21 fragments
would hit Jupiter over a one week period starting
on July 16, 1994, and everyone waited anxiously
for that day to arrive.
Alto Observatory image of the first impact
- July 16, 1994
The first image of the comet collision to
appear on the Internet
When the first impact hit(called Fragment A),
a plume sighting from the impact was reported
by Calar Alto Observartory in the Canary Islands
and the South African Astronomical Observatory
(SAAO). The Calar Alto and SAAO images of the
plume were quickly placed on the Internet just
a few hours after they were taken. The Calar Alto
images were taken in the infrared, and there was
no doubt of the first impact - showing a huge
explosion off the side of Jupiter. The Hubble
Space Telescope also took images of the impact,
but it took longer to download the images from
the spacecraft down to Earth. During a live NASA
press conference, Eugene and Carolyn Shoemaker
had mentioned the possible plume sigthings and
were anxiously awaiting the Hubble image, unaware
that images confirming the impacts were already
on the Internet. When the Hubble images did arrive,
a joyous Heide Hammel ran onto the stage with
the good news. Hubble had also detected the plume,
and showed the impact site on Jupiter as it rotated
into view - a feature that appeared as a black
eye on the top of the Jovian cloudtops. The first
impact was more visible than what everyone had
imagined, and everyone then knew they were in
for a week long extravaganza for the remaining
impacts. Comet fever had set in.
image taken from the Mount Stromlo and Siding
Observatory in Australia on July 18, 1994.
Fragment G was one of the larger fragments
of the comet.
Everyone around the world with a telescope were
now viewing Jupiter in earnest. The impact sites
were visible even fom the smallest amature telescopes.
A Internet frenzy ensued as hundreds of images
were made available on the World Wide Web. The
21 impacts were happening around the clock, so
someone around the world was able view each impact.
The plumes were particularly prominent in the
infrared, often oversaturating the infrared detectors,
but displaying spectacular images of the impact.
By sheer coincidence, the Galileo spacecraft,
enroute to Jupiter, was in position to view the
impact sites directly and took the only direct
measurements of the comet collisions.
showing the impact of Fragment W taken by
the Galileo spacecraft on July 22, 1994.
November 26, 2003