365daysDate: July 17, 2009

Title: The Lucifer Project


Podcaster: Brian Dunning

Organization: Skeptoid Podcast

Description: It started with a fanciful story idea by Arthur C. Clarke and Stanley Kubrick, and has grown into a detailed conspiracy theory. Some people believe the real reason for NASA’s deep space probes is to turn Saturn or Jupiter into a second sun.

Bio: Brian Dunning is the host and producer of the podcast Skeptoid: Critical Analysis of Pop Phenomena (, applying critical thinking to paranormal and pseudoscientific subjects promoted by the mass media. Skeptoid has a weekly audience of 70,000 listeners. Brian is also the author of two books based on the podcast, Skeptoid and Skeptoid II. A Silicon Valley computer scientist by trade, Brian now uses new media to promote critical thinking. He has appeared on numerous radio shows and television documentaries.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by NRAO.


One of the most dramatic events in Arthur C. Clarke’s 2001: A Space Odyssey series of books happens in the second installment, 2010: Odyssey Two. The strange alien monolith orbiting Jupiter somehow replicates itself billions of times, apparently using matter from Jupiter itself, condensing the gas giant down into a smaller, denser, hotter mass until it suddenly achieves sustained nuclear fusion. Thus, Jupiter fulfills the destiny denied it by nature as what some astronomers have termed a “failed star”. This new star brings life to its constellation of Earth-like moons, becoming a solar system within a solar system, and is named Lucifer by the people of Earth, who henceforth have two suns in the sky.

Most of us consider this the stuff of science fiction; there are too many physical reasons why it couldn’t actually happen. However, a number of conspiracy theorists believe that this is not only possible, but that it is an actual project in the works at NASA. And, moreover, that what they term “The Lucifer Project” has already been attempted.

Details vary, the most significant of which is the confusion over whether Lucifer would involve Jupiter or Saturn. The Space Odyssey movies and books all use Jupiter, except for the original book, which was based on an early version of Clarke and Kubrick’s screenplay that used Saturn (Saturn’s rings later proved too great of a special effects challenge.) Many of the modern conspiracy theories bring the story back around to Saturn as well, but really for all practical purposes we’re talking about “a gas giant,” think of either Saturn or Jupiter, whichever you please. Doesn’t make much difference as far as reality is concerned.

The main element of these deep-space NASA missions that fuels the conspiracy is the RTGs, or radioisotope thermoelectric generators, that power space probes such as Cassini, Galileo, Voyager, and others. Past Mars there’s not enough sunlight to provide the power a spacecraft needs, and so these RTGs are the only option we have. Heat from a radioactive element, usually plutonium-238, goes through a thermocouple, which is a material that produces a direct electrical current when heat is applied to it. RTGs have no moving parts and are extremely simple and reliable.

Believers in the Lucifer Project conjecture that such a payload of radioactive material would act like an atomic bomb in the high-pressure depths of a gas giant, and they suppose that this would somehow ignite the entire planet, turning the whole thing into a small star. This would act as a sun for its moons, turning them into habitable worlds.

In 2003, the Galileo spacecraft’s mission was ended by deliberately crashing it into Jupiter, in order to absolutely avoid any possibility of contaminating Jupiter’s moons with bacteria from Earth. Conspiracy theorists assert that this resulted in an atomic explosion within the depths of Jupiter, and that the protection of Jupiter’s moons from contamination was just a cover story for NASA’s attempted creation of Lucifer.

There are a number of differences between an RTG and an atomic or thermonuclear warhead. The grade of plutonium is one difference. The RTG uses reactor grade plutonium, while a weapon uses weapon-grade plutonium. But the main reason that an RTG could not explode like a weapon is its structure. Each of Cassini’s three RTGs contains 72 marshmallow-sized pellets of plutonium, each weighing about 150 grams, and each separately enclosed in iridium inside a shock-proof graphite impact shell. Four of each of these are enclosed within one of 18 separate General Purpose Heat Shell modules, each with its own separate heat shield and impact shell. Should any kind of crash or problem happen, including breaking up during a re-entry, these impact shells separate from each other and scatter.

Conversely, in order to detonate Pu-238, you need a single critical mass of solid plutonium weighing at least 10 kg. This critical mass has to be imploded with a simultaneous explosion from all sides, applying sudden pressure precisely from all angles at the same exact instant. Obviously this couldn’t happen with an RTG design. Although each RTG does theoretically have enough total plutonium to make up a critical mass, there isn’t any way that it could all be brought together into the right shape. An implosion triggered atomic device needs to have its critical mass in a very specific configuration. Any type of pressure or crash event has already sent all the separate impact shells scattering about space, and each is far too small to ever achieve critical mass and implode. No way, no how, physics simply do not make it possible for a chunk of less than critical mass to initiate a chain reaction, no matter what environment it’s put in.

Proponents of the NASA conspiracy state that the high pressure of the deep atmosphere inside a gas giant will provide the implosion pressure, but they do not offer a solution for the critical mass problem.

But let’s grant that an RTG could somehow result in an atomic explosion. Our largest thermonuclear tests didn’t turn the Earth into a small sun, they were a barely visible pinprick on our gigantic planet. So why would this far, far smaller explosion supposedly have such a drastic effect on a gas giant? Well, like our sun, the gas giants are composed largely of hydrogen and helium. In the intensely confined pressure inside an atomic explosion, fusion happens among these elements and causes the runaway thermonuclear chain reaction. In a nuclear explosion on Earth, this chain reaction quickly runs out, because of a lack of pressure and fuel. But inside the sun, there is tremendous fuel available and tremendous pressure from the sun’s powerful, crushing gravity. This is called gravitational confinement, and it’s the reason the sun’s nuclear reaction is ongoing.

Stars that are less massive than the sun have less gravity. Beyond a certain limit, they have inadequate gravitational confinement. These are called brown dwarfs, and their mass ranges from 1 to about 90 Jupiter masses. Above this limit, they would have adequate gravitational confinement and could sustain fusion. But inside this range, at which Jupiter is at the extreme lowest end, they don’t and can’t. An atomic or even thermonuclear explosion inside Jupiter would fizzle out the same way it does on Earth. Saturn, with less than a third of Jupiter’s mass, is even farther from achieving gravitational confinement.

Enjoy your science fiction stories and enjoy the science coming back through Cassini’s telemetry, but please don’t confuse the two. Saturn and Jupiter are here to stay.

End of podcast:

365 Days of Astronomy
The 365 Days of Astronomy Podcast is produced by the New Media Working Group of the International Year of Astronomy 2009. Audio post-production by Preston Gibson. Bandwidth donated by and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at or email us at Until tomorrow…goodbye.

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