dietz%usc-cse%USC-ECL%SRI-NIC@sri-unix.UUCP (01/04/84)
Using the deuterium on Venus got me thinking about other sources in the
solar system. An obvious one is Jupiter. Jupiter's core consists of a
small rocky/metallic center surrounded by lots of helium & metallic
hydrogen, at a temperature of about 54000 degrees K. My first thought
was that maybe the deuterium has settled out of the hydrogen under
gravitational forces, and maybe we could ignite this layer with a bomb.
This would probably destroy the planet, though, and there's no way of
getting a bomb that deep -- it would melt first.
If there was a way we could fuse some of the deuterium in Jupiter,
Jupiter would radiate more heat and the Jovian satellites would warm
up. Some have lots of water, so oceans could be formed. (Clarke had
the aliens doing this in "2010".)
Fusion reactions can be catalyzed by heavy negatively charged
particles, such as muons. Muons are about 200 times heavier than
electrons, so when one replaces an electron in a deuterium molecule the
nuclei are brought much closer together -- so close that they nearly
instantly fuse by quantum mechanical tunnelling. This process isn't
really economical on earth because you can't get enough fusion
reactions to occur before the muon is trapped by a reaction product
nucleus.
In Jupiter's core, however, the hydrogen and deuterium are in a dense
metallic state, which means that the electrons are not tied down in
orbits around individual nuclei. I would guess that a muon injected
into metallic deuterium would catalyse very many reactions -- possibly
millions or billions of fusions -- before it decayed. In Jupiter, the
reaction p + D --> He-3 + gamma would probably predominate, unless the
deuterium has separated, in which case D+D fusions could be induced.
But how to get the muons into Jupiter's core? While muons can
penetrate thousands of feet of rock, they can't reach the center of
Jupiter from the surface. What can? Neutrinos. The probability of a
neutrino reacting with matter increases linearly with neutrino energy.
At 10 trillion electron volts, the mean-free-path of a neutrino in
ordinary matter is about the diameter of the Earth. For this reason, a
group of physicists have recently proposed building a giant floating
accelerator to do a neutrino "CAT scan" of the Earth's innards
("Neutrino Exploration of the Earth", Science 4602 (220) 10 June 1983,
page 1142). The accelerator would produce 10 TeV protons, which would
slam into a fixed target. The debris produced would decay, producing
high energy neutrinos and antineutrinos. The decay tube, called the
"snout", would be a kilometer long and would have to be evacuated. It
would swivelled to scan the neutrino beam through the Earth. A
detector would be moved around on the other side of the planet. The
accelerator would be 30 kilometers in diameter, with a circumference of
over 100 miles. Before you scoff at this, remember that the next high
energy accelerator to be built in the US, the "Ultra High Energy
Accelerator" or "Desertron" (named after the probable location) will
have the same dimensions and produce 10-20 TeV protons. The Desertron
will cost somewhere around $1 billion to build, about twice what the
Fermilab "Tevatron" cost (in constant dollars), even though the energy
is much higher.
A high energy neutrino interacting with matter creates a particle
"shower" of more substantial particles. Even if a tiny fraction of the
10 TeV is converted to negative muons, many will be produced. These
muons are slowed as they pass through matter; they eventually come to
rest. In Jupiter, the muons would then catalyze many fusion reactions.
A fusion reaction liberates around 5 MeV of energy, so each muon could
catalyze the production of about 5 TeV of energy -- possibly orders of
magnitude more.
We can irradiate Jupiter from Earth, since neutrinos are stable
particles. Generating a beam of neutrinos with a spread of a few
seconds of arc would be necessary. Thermal pollution would probably
make Earth-surface based neutrino guns impractical; close solar orbit
seems like a better location. Planetary scientists will probably want
movable spacegoing neutrino guns to scan the insides of the planets,
moons and the sun, even if the physics makes astroforming Jupiter
impractical.dietz%usc-cse%USC-ECL%SRI-NIC@sri-unix.UUCP (01/10/84)
to create a ring around Jupiter by pulverizing an asteroid. The ring particles absorb the high energy electrons and protons (as they do around Saturn). Distortions can be induced in planetary magnetospheres, causing trapped particles to hit the planet. This was done around Earth in the 1960's with nuclear explosions. The terraformed jovian moons could be equiped with artificial magnetic fields. The core of Jupiter could be heated in such a way as to manipulate convection there, altering the Jovian magnetic field to reduce particle trapping.
kcarroll@utzoo.UUCP (Kieran A. Carroll) (01/11/84)
* From what I remember, the large amount of radiation near Jupiter comes not as direct radiation from the planet, but as high-energy particles trapped in Jupiter's version of Earth's van Allen belts. Only the very close satellites (perhaps only the closest one?) are affected by these particles; the outer satellites experience little more than solar and cosmic radiation. If Jove were to be ignited, making it an almost-failed star, the outer satellites might then receive enough heat to make them comfortable. Extra radiation from Jupiter's interior nuclear processes would increase the radiation environment of these satellites, but this might be compensated for by the growth of atmospheres about them, or at least about the icy ones. While I've made this sound authoritative, it isn't; it's merely speculation, based on what I remember of the Voyager data. -Kieran A. Carroll ...decvax!utzoo!kcarroll
Alpern.Ibm-Sj%Rand-Relay@sri-unix.UUCP (01/12/84)
From: David Alpern <Alpern.Ibm-Sj@Rand-Relay>
.... Distortions can be induced in
planetary magnetospheres, causing trapped particles to hit the planet.
This was done around Earth in the 1960's with nuclear explosions....
It was???? I'd be interested in hearing more about this. Was this a side
effect of some of the missile testing, or was this done on purpose? If the
latter, why?
- Daveucbesvax.turner@ucbcad.UUCP (01/14/84)
#R:sri-arpa:-1506300:ucbesvax:8700011:000:393 ucbesvax!turner Jan 7 18:30:00 1984 The idea of igniting a self-sustaining fusion process in the Jovian core (thereby turning our solar system into a binary-star system) is interesting--but would not make the Jovian planets more habitable. There is already too much radiation coming from Jupiter to make surface life on the larger (inner) planets of that system a working proposition. --- Michael Turner (ucbvax!ucbesvax.turner)
turner%ucbesvax%Berkeley@sri-unix.UUCP (01/16/84)
From: turner%ucbesvax@Berkeley (Michael Turner) Thanks for the correction. There remains the problem of equipping the appropriate Jovian moon with s suitable atmosphere. Any ideas on that one? -mike