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Space Science

Shoemaker-Levy Fragment's Impact Quantified 14

shotnicam writes: "[Here] is an article about particle G of the recent Shoemaker-Levy comet which slammed into Jupiter with the equivalent of 6,000,000 megatons of energy, more than 600 times the arsenal of the world. Also a bit of commentary on evolution, our progress so far, and what we have left to do." Good thing this hit a few planets over.
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Shoemaker-Levy Fragment's Impact Quantified

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  • This article doesn't really talk much about Shoemaker-Levy, but it does propose that we should travel to other planets. I agree. I would like to see the money we are spending on the international space station go to creating an international moon-base. If we create two compartments, one for humans and one for other animals (like Biosphere), we would be able to study how the radiation of space affects living things, what can adapt, and what can't, etc.
  • by JoeGee ( 85189 ) on Monday February 05, 2001 @09:19AM (#456427)

    I suspect if we can make it off planet and establish viable populations of terrestrial life elsewhere in the solar system we'll have more than enough time to spread far enough to avoid the nasty side effects of Alpha Centauri going BOOM in a few billion years.

    As I recall according to theory a supernova within twenty light years would release enough radiation to extinguish most life on Earth.

    If we can spread out thirty light years I'd wager we can be around until entropy makes life impossible. Even travelling at the best speeds attainable today the entire galaxy could be explored and settled within half the amount of time that hominids have been around on Earth.

    Assuming no major impacts within the next fifty years, no supernovae within the next thousand years, and no Darwinian cul-de-sac lurking in our genes I am pretty certain two million years from now some distantly-related Earthlife creature will look up at a sky full of stars and have a difficult time finding one that has NOT been visited by at least a hominid-originated robotic presence.

  • I found this link [rit.edu], a paper by a fellow named Michael Richmond entitled "Will a Nearby Supernova Endanger Life on Earth?" published in 1999.

    "Conclusion: I suspect that a type II explosion must be within a few parsecs of the Earth, certainly less than 10 pc (33 light years), to pose a danger to life on Earth. I suspect that a type Ia explosion, due to the larger amount of high-energy radiation, could be several times farther away. My guess is that the X-ray and gamma-ray radiation are the most important at large distances. "

    Unless we have a testy giant within a hundred LY or so a 30 LY radius should be far enough to move our eggs about to keep them from getting scrambled from any nearby booms. :)

    I liked your point about stellar motion -- did you see the recent photo of a white dwarf that appeared to be moving at high speed through the galactic ecliptic? One of those be-bopping through the solar system could certainly ruin one's day. :)

  • Assuming of course that we do not blow ourselves up, create machines that don't like us, infect ourselves with an incurable disease, or laze about like the late great Roman empire until we barely have enough motivation to lift our hands to our faces to eat -- forget about the fanciful idea of lifting a payload off planet.

    :)

  • it would kill us all, isnt it only 9 ly from us and ready to go any second?
  • by Christopher Thomas ( 11717 ) on Monday February 05, 2001 @11:41AM (#456431)
    I would like to see the money we are spending on the international space station go to creating an international moon-base. If we create two compartments, one for humans and one for other animals (like Biosphere), we would be able to study how the radiation of space affects living things, what can adapt, and what can't, etc.

    The ISS is still a pretty necessary first step. It gives us a place nearby where we can test most of our habitat technology without being out of rescue range, and we can study radiation effects just as easily there as on the moon. It also lets us further study the effects of microgravity, which we'll need to have a very good handle on before attempting a Mars mission (for most craft designs I've heard about, at least).

    The ISS is also an excellent launch platform and docking station for lunar-orbit craft. This would let you use ion- or plasma-drive craft that wouldn't be able to land to move easily between earth- and lunar-orbit and back, establish a permanent space station around the _moon_, and in general make the logistics of earth/moon travel and lunar exploration/colonization much easier.

    Keeping the ground-to-orbit steps of lunar missions (on both ends) separate from the orbit-to-orbit step makes it a *lot* easier to plan lunar surface missions, gives them a greater chance of success, and makes it easier to recover from catastrophes at most stages.
  • I'll give the original author the benefit of the doubt and say he knew what he wanted to say and chose poor wording to express what he was saying. The problem with evolutionary scientists is two-fold. Some of them actually believe that evolution is a replacement for God (in the Christian sense of the word) and always try to fit emotions, thought, plans and dreams into the "reasons" behind evolution (much like Christians pretend to understand the motivations behind God's supposed actions). Others, knowing full well that evolution isn't a being try very, very hard to speak in this evolution as god riddle so as to show the common man how superior they are (because they know the intentions of the "real" god, EVOLUTION).

    The fact is that evolution is no more real the the Christian god if you are looking for a supreme intelligence/being. They are both random purposes brought about by the very, very chaotic nature that they somehow made into seemingly non-chaotic matter. A human being is an extremely organized creature, but when you begin studying the organization you begin to realize that no one, no thing would ever intentionally design a creature the way we have been 'designed' (if you can call it that). With so many inneffecient body parts, and body parts that just don't really seem to do much, there is no way you can attribute it to anything but chaos breeding a sort of psuedo-order through evolutionary means (when something works, go with it, something doesn't, get rid of it). No mystical powers involved, just a beautiful coincidence.

  • this guy seems to think humanity was evolved for some evolutionary purpose, which seems to me very silly. evolution doesn't have a plan for us. evolution isn't an old man in the sky that figures out the risks of life getting wiped out on Earth and so decides to develop humans for a grand purpose. evolution is just natural selection, unconsciously doing its thing to select genes that code for beneficial adaptations. the fact that one of its products (us) is able to detect a threat to some of its works (life on Earth) is about as intentional as the weather.
  • The author somehow seemed to have a fixation about sex and evolutionary imperatives (overpopulating the Earth and all that too). But the message to expand beyond our one planet and one star system is clear; if we could direct some of the billions that would have gone into dot.coms into the various space startups we might really get somewhere. I do think it has to be through private enterprise initiative - NASA's view is too tied to the restrictive national security priorities that make it do things like force commercial companies to use the shuttle, rely on defence contractors with their obscene billing practices and skewed priorities, and balk at "tourists" like Tito coming to their station.
  • I thought the "kill radius" was a lot more than 20LY -- perhaps something as much as a 1000 LY for anything larger than the proverbial mouse.

    The problem is that nearby systems will be whipsawed. First there will be a *lot* more energy pouring into the system - even an extra 5-10% of "sunlight" for a three-month period could seriously mess up an ecosystem. A few hundred to a thousand years later, when the ecosystem is finally recovering, the dust blows through and it could drop the sunlight by the same amount for years. Instant ice age. Of course, the star will also be getting sandblasted by that dust, so once the dust clears the star will still have its chromosphere chewed up. I can't remember if that makes it brighter or dimmer (if the turbulence slows down convection). Either way, the ecosystem is history.

    (Obviously anything in orbit is toast. That "dust" is still traveling fast enough to be considered intense radiation.)

    The good news is that we don't have to go 1000 LY out ourselves. If humanity reaches a reasonable number of stars, their natural movements will continue to separate the colonies even if all lose interstellar capability.
  • "it's probably just a fluke we made it this far, but we will soon have the capability to survive anything short of a nearby supernova or gamma ray burst."

    Soon.. but when and what about internal disaters like earthquakes and floods and draughts?

  • According to the Hipparcos data (the best there is currently), Betelgeuse is about 430 light years away. While it is relatively close in astronomical terms to the point in its life where it might go *bang*, in human terms it could be a very long time (i.e., thousands of years). It is one of the closest stars big enough to be a potential problem.
  • Betelgeuse is far enough out that it should not be a problem for Earth. It might make space travel really risky for a while tho.

    I think it would be interesting to try to find correspondences between archaic supernovae and periods of rapid evolution. I suspect one might be able to find a correlation between rapid sppecies die off and repopulation, and periods of high mutation due to an increase in background radiation.

    Remember in 4.5 billion years there have been plenty of nearby stars that have gone pop. Life is still here. Again a question that interests me is how life has been influenced by nearby stellar deaths. :)

  • Are you thinking Barnard's Star? It's a red giant 14 LY out from us?

    As I recall it's a main sequence star late in its life. It's going to die rather sedately and quietly, and end up a cinder.

    (I may be wrong -- I do not currently have time to look this one up.)

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