Shoemaker Levy 9

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Shoemaker Levy 9

• Indunil Fernando
• Astronomy 330

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Importance

• First ever collision between two bodies in the
  solar system that was observed.
• Was discovered by amateur astronomer David Levy
  and his two friends Caroline and Eugene Shoemaker
• Was the 9th object/comet discovered by them
• Thought to be an object that specifically orbits
  Jupiter, rather than the sun

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Specifics

• Short, periodic comet
• Formally designated D/1993 F2
• Was found on the 24th of March 1993 on the
  Schmidt telescope on Mt. Palomar, CA.
• Was found by other groups of astronomers around
  the same time, with exposures predating the
  official discovery, but credit was given to
  Shoemaker and Levy

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Some Facts

• Highly elongated and very loose orbit around
  Jupiter
• Was broken into 21 pieces when it passed Jupiter
  in 1992
• Happened because the comet passed within the
  Planets Roche limit
• Roche limit is the distance beyond which the
  planets tidal forces can break apart an object
  held together by gravity
• The fragments were named after letters in the
  alphabet, A through W

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Collisions

• Fragments ranged from a several hundred meters to
  several kilometers across.
• Led to a calculation of the nucleus of the comet,
  which was estimated to be around 5 km
• Even before the actual collisions, calculations
  had predicted that the fragments would collide
  with Jupiter, not simply fly by.

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More on Collisions

• Galileo, the HST, the ROSAT X-Ray satellite,
  Ulysses, and even Voyager 2 were looking at the
  impacts.
• Some of the more forceful impacts were seen even
  after months. They were even more visible that
  the Great Red Spot
• Occurred between the 16th and 22nd of July 1994
• Speeds were measured to be around the vicinity of
  6o km/s

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Images

• Series of shots taken as a fragment traveled to
  Jupiter
• Shows relative scale and angle of impact

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Images

• Taken by the HST in the Ultraviolet, around 2500
  Angstrom
• Shows the impacts of several fragments.
• The largest impact was fragment G, whose energy
  imparted was equivalent to 750 Megatons of TNT
• Was around the radius of EARTH!!!

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What happened after

• The collisions imparted so much energy that
  seismic waves were generated
• Was observed at around 450 km/s , even 2 hours
  after the larger impacts
• Are generally thought to the gravity waves.
• Jupiter on the whole however, managed to stay
  stable, thanks to the larger size.

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References

• http//www2.jpl.nasa.gov/sl9/
• http//upload.wikimedia.org/wikipedia/en/2/28/Mont
  age_of_Jupiter_and_SL9.jpg
• Text - Shoemaker by Levy the Man who made an
  Impact