Dear astros paste the link below in your browser to download this pdf.a
small read up on a event that took place back 2003:)thank you.
http://www.divshare.com/download/70276-4e7
Did NASA Accidentally “Nuke” Jupiter
Hi Ravi,
Better if you just gave the relevant websites:
http://www.enterprisemission.com/NukingJupiter.html
http://www.space.com/scienceastronomy/j ... 31023.html
Next time, could you give more information in your post? It would help other readers understand your post. For example, give an introduction; what questions are you asking; why do you find it interesting; what do you want people to comment about?
Also, "general astronomy" would have been a better section to post it under.
Thanks for understanding and helping!
Chris
Better if you just gave the relevant websites:
http://www.enterprisemission.com/NukingJupiter.html
http://www.space.com/scienceastronomy/j ... 31023.html
Next time, could you give more information in your post? It would help other readers understand your post. For example, give an introduction; what questions are you asking; why do you find it interesting; what do you want people to comment about?
Also, "general astronomy" would have been a better section to post it under.
Thanks for understanding and helping!
Chris
Last edited by chrisyeo on Thu Jan 25, 2007 3:44 am, edited 2 times in total.
Hi Ravi,
I’m no expert on nuclear physics but let me give you some reasons why I think the scenario of Galileo exploding atomically in Jupiter is unlikely.
1. Nuclear explosion of Plutonium238 pellets is unlikely:
a. Pu238 is non-fissle as compared to Pu239. Even if you could get a nuclear reaction going, it would not lead to a nuclear explosion. It is like U238: “Not all fissionable isotopes can sustain a chain reaction. For example, 238U, the most abundant form of uranium, is fissionable but not fissile: it undergoes induced fission when impacted by an energetic neutron with over 1 MeV of kinetic energy. But too few of the neutrons produced by 238U fission are energetic enough to induce further fissions in 238U, so no chain reaction is possible with this isotope. Instead, bombarding 238U with slow neutrons causes it to absorb them (becoming 239U) and decay by beta emission to 239Pu; that process is used to manufacture 239Pu in breeder reactors, but does not contribute to a neutron chain reaction.” [ http://en.wikipedia.org/wiki/Nuclear_fi ... _reactions ]
b. Even if you dropped Pu239 into Jupiter it is unlikely to explode. Even if Jupiter’s pressure were high enough, the material does not reach some critical mass and then suddenly ignite. How nuclear reactions work is that emitted neutrons trigger other reactions, resulting in a sustained chain reaction in which all the energy is released at once. If however if you slowly compressed the material what happens is that you get an increasing rate of nuclear reactions. Most of the fuel would have been spent by the time you reach critical density for a runaway reaction. You get a nuclear fizzle rather than an explosion.
– can someone knowleagable in nuclear physics correct me if I am wrong on these points?
c. Even if one of the pellets exploded, it would not set off the other pellets in the “spherical falling “cloud” [of pellets] a few tens of miles across”. What is critical here is not pressure or heat as in conventional explosives, but the high-energy neutrons. A nuclear explosion will not ‘ignite’ another bomb even if it was placed 10 meters away, much less a mile. Also, tens of miles is grossly understated. Imagine falling 700 miles in 700mile/hr winds for 1 month. The pellets will more likely have spread hundreds of miles.
2. Even if there was an explosion, the explosion would have been too small to explain the cloud. The spot in the photo looks about the size of the scar that the impact of the largest fragment of shoemaker-levy created. That impact was estimated to have released an energy equivalent to 6,000,000 megatons of TNT (750 times the world's nuclear arsenal) [ http://en.wikipedia.org/wiki/Shoemaker_Levy#Impacts ]. Galileo’s plutonium yield is so tiny that it would not have left a scar even if it exploded on the surface.
3. If you look at the picture, it was taken through a small refracting telescope. Processing of such images can lead to misleading features. Take for example a picture I took myself http://www.singastro.org/album_showpage.php?pic_id=310 and Gavin’s http://www.singastro.org/album_showpage.php?pic_id=473 . Do they not show Jupiter’s with mysterious dark clouds? As the space.com article put it: “Another well seasoned Jupiter observer weighed in late Thursday, suggesting that dark spots in the Jovian clouds are not as rare as some astronomers think. Nonetheless, scientists know little about what causes the spots.” My take is that there are more processing artefacts then real dark clouds. A small blurry image is no proof of anything mysterious or special, and explains why scientists do not disrupt schedules booked years in advance to turn telescopes to look at ‘unexplained dark spots’.
The reason why scientists reacted with “non-curiosity” was simply because there probably was nothing curious at all. There are plenty of outlandish theories and conspiracy stories out there that when well written seem very convincing. However, we should not be taken in but instead arm ourselves with the proper scientific knowledge to make the correct judgements on these issues. I hope that I've helped to explain some things and to encourage others to learn more about science.
Thanks for reading!
Regards,
Chris
I’m no expert on nuclear physics but let me give you some reasons why I think the scenario of Galileo exploding atomically in Jupiter is unlikely.
1. Nuclear explosion of Plutonium238 pellets is unlikely:
a. Pu238 is non-fissle as compared to Pu239. Even if you could get a nuclear reaction going, it would not lead to a nuclear explosion. It is like U238: “Not all fissionable isotopes can sustain a chain reaction. For example, 238U, the most abundant form of uranium, is fissionable but not fissile: it undergoes induced fission when impacted by an energetic neutron with over 1 MeV of kinetic energy. But too few of the neutrons produced by 238U fission are energetic enough to induce further fissions in 238U, so no chain reaction is possible with this isotope. Instead, bombarding 238U with slow neutrons causes it to absorb them (becoming 239U) and decay by beta emission to 239Pu; that process is used to manufacture 239Pu in breeder reactors, but does not contribute to a neutron chain reaction.” [ http://en.wikipedia.org/wiki/Nuclear_fi ... _reactions ]
b. Even if you dropped Pu239 into Jupiter it is unlikely to explode. Even if Jupiter’s pressure were high enough, the material does not reach some critical mass and then suddenly ignite. How nuclear reactions work is that emitted neutrons trigger other reactions, resulting in a sustained chain reaction in which all the energy is released at once. If however if you slowly compressed the material what happens is that you get an increasing rate of nuclear reactions. Most of the fuel would have been spent by the time you reach critical density for a runaway reaction. You get a nuclear fizzle rather than an explosion.
– can someone knowleagable in nuclear physics correct me if I am wrong on these points?
c. Even if one of the pellets exploded, it would not set off the other pellets in the “spherical falling “cloud” [of pellets] a few tens of miles across”. What is critical here is not pressure or heat as in conventional explosives, but the high-energy neutrons. A nuclear explosion will not ‘ignite’ another bomb even if it was placed 10 meters away, much less a mile. Also, tens of miles is grossly understated. Imagine falling 700 miles in 700mile/hr winds for 1 month. The pellets will more likely have spread hundreds of miles.
2. Even if there was an explosion, the explosion would have been too small to explain the cloud. The spot in the photo looks about the size of the scar that the impact of the largest fragment of shoemaker-levy created. That impact was estimated to have released an energy equivalent to 6,000,000 megatons of TNT (750 times the world's nuclear arsenal) [ http://en.wikipedia.org/wiki/Shoemaker_Levy#Impacts ]. Galileo’s plutonium yield is so tiny that it would not have left a scar even if it exploded on the surface.
3. If you look at the picture, it was taken through a small refracting telescope. Processing of such images can lead to misleading features. Take for example a picture I took myself http://www.singastro.org/album_showpage.php?pic_id=310 and Gavin’s http://www.singastro.org/album_showpage.php?pic_id=473 . Do they not show Jupiter’s with mysterious dark clouds? As the space.com article put it: “Another well seasoned Jupiter observer weighed in late Thursday, suggesting that dark spots in the Jovian clouds are not as rare as some astronomers think. Nonetheless, scientists know little about what causes the spots.” My take is that there are more processing artefacts then real dark clouds. A small blurry image is no proof of anything mysterious or special, and explains why scientists do not disrupt schedules booked years in advance to turn telescopes to look at ‘unexplained dark spots’.
The reason why scientists reacted with “non-curiosity” was simply because there probably was nothing curious at all. There are plenty of outlandish theories and conspiracy stories out there that when well written seem very convincing. However, we should not be taken in but instead arm ourselves with the proper scientific knowledge to make the correct judgements on these issues. I hope that I've helped to explain some things and to encourage others to learn more about science.
Thanks for reading!
Regards,
Chris
.thank you.