Slashdot is powered by your submissions, so send in your scoop


Forgot your password?

Shoemaker-Levy 9's 10th Anniversary 26

Chuck1318 writes "July 16 is the 10th anniversary of the first impact of pieces of the comet Shoemaker-Levy 9 on the planet Jupiter. The Planetary Society is marking this occasion with a call for applications for Shoemaker grants to fund "amateur and underfunded professional observers anywhere in the world." Shoemaker-Levy 9 created impact features on Jupiter that were larger than the Earth and helped stimulate the search for possible earth-impacting objects."
This discussion has been archived. No new comments can be posted.

Shoemaker-Levy 9's 10th Anniversary

Comments Filter:
  • Thank you, Jupiter! (Score:4, Interesting)

    by adeyadey ( 678765 ) on Saturday July 17, 2004 @05:10PM (#9726738) Journal
    You can thank Jupiter for catching comets like shoemaker-levy. More recent theories indicate that Jupiter acts like a giant hoover, catching debris that would otherwise end up hitting earth, which in turn would make advanced life on Earth impossible due to frequency of large impacts.

    Even as it is, impacts the size of the Meteor that hit Tunguska, Siberia in 1907 probably happen every at least century or so - and if that happened over New York, you can say goodbye NY..

    • Wasn't the 1907 Siberia impact actually a Tesla experiment gone horribly wrong?
    • I would think that the other outer planets would play a significant role in that theory. While jupiter is on one side of the solar system, meteors could swing in from the other side and pound the earth. I would think that all the outer planets would form a net to catch asteroids. Of course, that's if you treat the univserse as 2D, there's still stuff approaching from vectors perpendicular to the general orientation of the solar system. In that sense, the large outer planets could actually deflect stuff
      • True, but... (Score:5, Interesting)

        by DrMorpheus ( 642706 ) on Saturday July 17, 2004 @05:53PM (#9727002) Homepage
        You have to remember that most of the material that the solar system accreated from was in a disk around the sun. So most of the dangerous debris is on the plane of the ecliptic, which sorta renders the Solar System 2D.

        Now the gas giants do indeed "hoover" up a lot of the space debris that might otherwise hit the inner planets you also have to realize that they're also responsible for causing debris from the Kuniper Belt and Oort Cloud to decend out of their respective places in the outer Solar System into the inner Solar System. Due to gravitational perturbation.

        So I'd argue the gas giants are sort of a mixed blessing overall.

        • Re:True, but... (Score:3, Interesting)

          by barakn ( 641218 )
          And also asteroids within the main belt that get to close to a resonant orbit. This phenomenon is invoked to explain how the remnants of collisions in the asteroid belt can arrive at Earth so quickly []. It's better to think of the giant planets as orbit randomizers than as Hoovers.
          • Re:True, but... (Score:2, Interesting)

            by Chuck1318 ( 795796 )
            The thing that amazed me when I read about that collision is that even today, 500 million years later, 20 per cent [] of all meteorites are remnants from that collision.
        • I seriously doubt that the gravitational forces of the outer planets have any influence whatsoever on the Oort cloud. I think that with the distances involved even the gravity of Jupiter would be negligible compared to the Sun's. Of course IANA astronomer, anyone care to provide some calculations?

          Oh, and the other one is called the Kuiper Belt. How did that 'n' ever sneak up there? :)

          • ;-)

            Well your doubts have no basis in fact, as this link shows [].

            The Oort cloud is the source of long-period comets and possibly higher-inclination intermediate comets that were pulled into shorter period orbits by the planets, such as Halley and Swift-Tuttle. Comets can also shift their orbits due to jets of gas and dust that rocket from their icy surface as they approach the sun. Although they get off course, comets do have initial orbits with widely different ranges, from 200 years to once every milli

            • Alright, even though earlier in the article other forces are named as the main actors on Oort Cloud comets. I read the part that you quote as "once the comet is nudged towards the sun, the bigger planets can then influence the orbits so they become shorter".

              Why do I still doubt it? Jupiter mass is only 0.001 solar mass [], Oort cloud distance is in the order of magnitude of 100,000 AU [], gravity influence decreases with distance squared, and comets are small.

              But hey, the Oort Cloud has not even been proven []
        • debris from the Kuniper Belt
          It's Juniper belt, fool.
    • thank goodness for our atmosphere...anyone know how fast meteors and comets move through space...without lookin it up?
      • First of all, one nitpick: Meteors don't move through space; a particle only becomes a meteor when it begins burning up in the atmosphere. A particle falling into earth's gravity well will build up kinetic energy equal to the potential energy it is giving up, so it will have at least escape velocity from the earth when it reaches atmosphere and becomes a meteor, 11 km/sec. Long period comets fall into the Sun's gravity well from just about the top, so its kinetic energy will be almost escape velocity from
  • SL9 was awesome (Score:3, Informative)

    by LMCBoy ( 185365 ) on Saturday July 17, 2004 @06:38PM (#9727225) Homepage Journal
    I was an undergrad at the time; we were watching Jupiter with the Steward Observatory 21-inch telescope []. The actual impact events were not visible from Earth, but as Jupiter spun around, we saw the scars left by the impacts. Very exciting stuff!
  • Wow... (Score:4, Informative)

    by eingram ( 633624 ) on Sunday July 18, 2004 @12:03AM (#9728768)
    10 years? It really does seem like yesterday. Shit! I was thirteen! My dad took me up to the local science type place where they had telescopes lined up. I peered through the telescope and I was able to see "a bruise" on Jupiter! Jupiter! I thought it was quite cool and I've been hooked ever since. I hope more celestial events like this take place in my lifetime.
  • From Bill Higgins's USENET post to of 1997/09/03 [], reposted here without his permission but I think he'll understand :)

    Super Comet Fragment Impact
    Jordin T. Kare and Bill Higgins
    Copyright 1994 by Jordin T. Kare and Bill Higgins

    So Bill asked innocently whether anyone had written a song about the
    Jovian Train Wreck, and the Muse of Parody tortured Jordin until the
    answer was "yes." Tune: "Supercalifragilisticexpialidocious," of


    Super comet fragment imp

Executive ability is deciding quickly and getting somebody else to do the work. -- John G. Pollard