The Poisonous Comet

Discussion in 'Astronomy, Exobiology, & Cosmology' started by brights, Jul 7, 2007.

  1. brights Registered Senior Member

    Messages:
    52
    What if a comet hits Earth? What if the fragments hits our lakes and reservoirs poisoning it and making the water undrinkable?

    "comet tails do contain an extremely poisonous chemical compound - hydrogen cyanide."

    http://www.space.com/scienceastronomy/astronomy/comet_poison_011012.html

    "Apart from their rocky content, comets are made mostly of water-ice, plus frozen methane, ammonia, carbon monoxide, and carbon dioxide. They also contain an interesting collection of organic chemicals, including methanal (H2CO), hydrogen cyanide (HCN), and methyl cyanide (CH3CN),"

    http://www.daviddarling.info/encyclopedia/C/comet.html

    "Cometary hydrogen cyanide was first observed by Huebner, Snyder, & Buhl (1974) in comet Kohoutek. It has since been seen in a number of comets, including P/Halley (Schloerb et al. 1987), P/Brorsen-Metcalf, Austin, and Levy (Colom et al. 1991), P/Swift-Tuttle (Wootten, Latter, & Despois 1994), Hyakutake (Irvine et al. 1996), and, most recently, Hale-Bopp (Rauer et al. 1996; Biver et al. 1997). HCN has a typical abundance relative to water of 2 10×10 , and since there are no photochemical processes capable of forming this amount of HCN from either NH3 or N2, it is thought to be a parent species. Irvine et al. (1996) also observed hydrogen isocyanide (HNC) in Hyakutake, and they determined the HNC/HCN ratio to be 0.06. Biver et al. (1997) observed HNC in Hale-Bopp and found that the HNC/HCN ratio increased as the comet approached the Sun, from less than 0.02 at 2.9 AU up to 0.1 at 1.4 AU. Irvine et al. proposed four possible explanations for the origin of HNC: (1) HNC is also a parent species; (2) gas-phase chemical processing converts HCN into HNC; (3) photoexcited HCN decays to give HNC; and (4) HNC is produced via photodissociation of large molecules/dust grains."

    http://www.journals.uchicago.edu/Ap...6/975706.html?erFrom=6519133302219142118Guest

    "Hydrogen cyanide is a chemical compound with chemical formula HCN. A solution of hydrogen cyanide in water is called hydrocyanic acid. Hydrogen cyanide is a colorless, very poisonous, and highly volatile liquid that boils slightly above room temperature at 26 °C. HCN has a faint, bitter, almond-like odor that some people are unable to detect due to a genetic trait.[1] Hydrogen cyanide is weakly acidic and partly ionizes in solution to give the cyanide anion, CN–. The salts of hydrogen cyanide are known as cyanides. HCN is a highly valuable precursor to many chemical compounds ranging from polymers to pharmaceuticals."

    http://en.wikipedia.org/wiki/Hydrogen_cyanide


    ...

    So, what if a comet hits our water supply? Where would we get water then? How are we able to cope?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Hydrogen Cyanide in what concentration? There would have to be an awful lot of it to contaminate ALL the water on Earth. Also, we can get rid of most anions that are dissolved in water by a process called dionization.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Repo Man Valued Senior Member

    Messages:
    4,955
    I think any concerns about cyanide contamination pales when compared to the damage of the impact. A direct hit of a large comet in the right place could have consequences so severe it would reset the civilization clock, and bring on a new dark age.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. brights Registered Senior Member

    Messages:
    52
    What I'm pointing here is our fresh water supply as shown on this site:

    "The fresh water actually available for human use in lakes and rivers and the accessible ground water amount to only about one-third of 1% of the world's total water supply."

    http://www.infoplease.com/ipa/A0004674.html


    ...

    The concentration of HCN will depend on the size of the comet. HCN mixed with water will produce hydrocyanic acid or Prussic Acid.

    "Prussic acid is a potent, rapidly acting poison. Signs of prussic acid poisoning can occur within 15 to 20 minutes to a few hours after animals consume the toxic forage. Animals are often found dead. Clinical signs, when noticed, occur in rapid succession. Excitement, rapid pulse, and generalized muscle tremors occur initially, followed by rapid and labored breathing, staggering, and collapse. There may be salivation (drooling), lacrimation (runny eyes) and voiding of urine and feces. The mucous membranes are usually bright pink, and the blood will be a characteristic bright cherry red."

    http://www.ag.ndsu.edu/pubs/ansci/livestoc/v1150w.htm


    We should not include ground water sources as this is not affected by the comet, only rivers, lakes and reservoirs, which account only so much about 30,300 cu mi. Let say, only 1/3 of this will be hit by a comet. How are we able to cope with this? Many people will die either of thirst or HCN poisoning.
     
  8. brights Registered Senior Member

    Messages:
    52
    That's a common answer nowadays. What I'm trying to study here are the other "effects" when a comet hits. For me, an impact is just too simple an observation. We should include other factors as well, like the chemical composition of a comet, among other things.

    Comets and meteorites do fragment upon entering the atmosphere, hitting several places on Earth at a time making the mass less likely to cause extinction, but enough to cause ecological chain reaction disaster. I view this as a chemical weapon of nature rather than a study of a simple impact of a bullet.

    I think this is a more realistic approach to studying this disaster.
     
  9. Janus58 Valued Senior Member

    Messages:
    2,394
    The HCN concentratration in a comet is about 1 part in 500.

    Given a typical mass comet of 10[sup]13[/sup] kg, this gives a total HCN content of 2 x 10[sup]10[/sup] kg. If this were spread throughout the atmosphere (5 x 10[sup]18[/sup] kg), you would get a concentration of about .002 ppm (parts per million by volume).

    Normal unpolluted air already has a concentration of .2 ppm HCN.

    It takes about 6 ppm for a person to start showing heath effects over a long term exposure of years.

    So even if an entire comet dumped its HCN into our atmosphere, it wouldn't be enough to cause any problems.
     
  10. brights Registered Senior Member

    Messages:
    52
    Base on your calculation, how big does a lake have to be in order to be contaminated with HCN?
     
  11. Orleander OH JOY!!!! Valued Senior Member

    Messages:
    25,817
    Hasn't the Tunguska Meteorite been determined to be a comet? Did it affect the water there?
     
  12. pinkiss Registered Senior Member

    Messages:
    70
    first off all there are millions of lakes in the world which are used for drinking water and if one gets polluted there will be plenty left.Other than that think about all chemicals buried in the oceans and radioactive waste which is greater threat than any comet.
     
  13. brights Registered Senior Member

    Messages:
    52
    It didn't land on water.
     
  14. brights Registered Senior Member

    Messages:
    52
    If a comet fragment hits just one river, imagine how many places will be affected. Take for example, Mississipi River which is 5,971 Km long. Looking at the map below, how many places will be affected?

    Please Register or Log in to view the hidden image!



    And, by looking at the Yangtze River in China which is 6,380 Km long, how many places will be affected?

    Please Register or Log in to view the hidden image!



    All it takes is a poisonous fragment of the comet to pollute the whole line and affect many places.

    Although, there are still many sources of water, we can only use 1/3 of 1% of the total world supply of fresh water.
    Water is a very precious thing and anything which disturbs this 1/3 minuscule amount will result in disaster.
     
    Last edited: Jul 10, 2007

Share This Page