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Shoemaker-Levy 9's 10th Anniversary

Posted by timothy on from the gifts-of-tinfoils-hats-are-appropriate dept.

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."

9 of 26 comments (clear)

  1. Thank you, Jupiter! by adeyadey · · Score: 3, Interesting

    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..

    --
    "You lied to me! There is a Swansea!"
    1. Re:Thank you, Jupiter! by Chuck1318 · · Score: 3, Informative

      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 its distance from the sun at any time. At the earth's orbit, its velocity would be (um, mumble 30 km/sec times the square root of two, mumble) about 42 km/sec. Short period comets would have whatever orbital speed is determined by its orbit.

    2. Re:Thank you, Jupiter! by another_henry · · Score: 2, Funny

      No. Tesla was not a magician, just a good physicist and engineer with some incorrect ideas.

      --
      "Studies have shown that people who eat peanuts live longer than those who do not eat."
  2. What about Saturn, Uranus, and Neptune? by MagicDude · · Score: 2, Informative

    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 into the earth if it's initially on a vector that wouldn't ordinarily meet with the earth.

  3. True, but... by DrMorpheus · · Score: 4, Interesting
    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.

    --
    Debunking the "59 Deceits"
    1. Re:True, but... by barakn · · Score: 2, Interesting

      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.

      --
      "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
    2. Re:True, but... by Chuck1318 · · Score: 2, Interesting

      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.

  4. SL9 was awesome by LMCBoy · · Score: 2, Informative

    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!

    --
    Liberal (adj.): Free from bigotry; open to progress; tolerant of others.
  5. Wow... by eingram · · Score: 3, Informative

    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.