Did NASA Accidentally “Nuke” Jupiter?

enterprisemission.com ^ | 2003 | Richard C. Hoagland

[grundle]

On September 21, 2003 NASA deliberately directed its amazing, still-functioning Galileo spacecraft to make one final, 108,000 mph suicidal plunge into Jupiter’s vast atmosphere.

The intent of this unfortunate decision was to protect Europa, one of those Jovian moons.

Van der Worp claimed that, plunging into Jupiter’s deep and increasingly dense atmosphere, the on-board Galileo electrical power supply – a set of 144 plutonium-238 fuel pellets... would ultimately “implode”; that the plutonium Galileo carried would ultimately collapse in upon itself under the enormous pressures of Jupiter’s overwhelming atmosphere—

As the capsules continue to fall deeper through the primarily hydrogen atmosphere, the surrounding pressure/density continues to rise, to thousands of times Earth’s surface density and pressure. The capsules are now falling at a constant rate, approximately one mile per hour

At this ultra-slow “terminal velocity,” it takes the Galileo plutonium-238 capsules on the order of 700 hours – a month! to fall to a depth inside Jupiter (~700 miles below the visible clouds) where the outside pressure of the surrounding liquid hydrogen literally crushes the plutonium capsules into a supercritical state—

At this point, one of the capsules randomly implodes … and initiates, via the resulting shockwave and intense neutron shower, a runaway nuclear chain reaction in all the other surviving capsules, now spread in a spherical falling “cloud” a few tens of miles across ~700 miles below Jupiter’s visible “surface.” The resulting cascade nuclear detonation of all the surviving capsules totals several tens of kilotons ….

The deliberate destruction of Galileo to “save” Europa, and the sudden appearance of “a mysterious dark splotch” on Jupiter just one month later -- precisely time enough to get the entering plutonium down to a depth where it could catastrophically implode – is truly a remarkable “coincidence.”

[The_Media_never_lie]

As I recall, you get a “bonus” of 1 MeV when you go from odd to even numbers of nucleons in the neutron capture event. The binding energy gets you about 5 MeV, the “bonus” of 1 MeV going from odd to even gets you one more, for a total of 6 MeV, just the amount you need to add to the nucleus to induce the fission reaction. U238 neutron capture goes from even to odd, so you don’t get the bonus. The 5 MeV you get from the binding energy isn’t enough to do it for thermal neutron-induced fission. You need an incoming “fast” neutron (1 MeV or more) to fission the U238 nucleus. So it is a threshold reaction rather than a thermal neutron capture. Do I have the numbers right (it’s been awhile)

Please, don't even think about a trip to Iran any time soon.

[RadioAstronomer]

Here is a good chart showing Isotope Netron Cross Sections including 235 and 238. :-)

http://ie.lbl.gov/ngdata/sig.htm

(Look at sigma (F)

[chimera]

Yeah, I have those graphs. I was wondering about the 1 MeV “bonus” going from odd to even nucleon numbers. My nuclear theory is a bit rusty, but this is the number I seem to recall.

[chimera]

Well, as a matter of fact, one of my students was thinking about “going home” (Shiraz) after he graduated. I have been trying mightily to get him to change his mind. Trouble is, where is he going to go? Jobs here in the nuclear business are pretty much forbidden for people from countries that aren’t signatories to the NPT. I’m hoping we can keep him on as a postdoc until he gets his citizenship (he is not an illegal alien).

[SunkenCiv]

An atomic explosion on the order of the Fat Man wouldn’t (on its own) make any kind of obvious mark on the surface of Jupiter. Each of the SL-9 impacts exceeded the energy of Fat Man. But Hoaxland is always good for some laughs.