Project GALILEO (Cooper)
Project GALILEO is an alleged JASON Society operation described by William Cooper in his 1991 book Behold a Pale Horse whose mission was to use the NASA Galileo spacecraft's plutonium payload to ignite Jupiter's hydrogen and helium atmosphere, triggering a sustained nuclear reaction and creating a second sun-like body — designated "LUCIFER" in the project plan — ostensibly to stave off a coming ice age by supplementing Earth's solar energy intake, while simultaneously fulfilling what Cooper characterized as Masonic prophetic expectations. Cooper stated "only five pounds of plutonium" would suffice to ignite Jupiter, and placed his awareness of the program at approximately June 1972 during his Naval Intelligence service. Project GALILEO does not appear in Cooper's own Operation Majority project list of alien-related programs (which includes SIGMA, PLATO, AQUARIUS, GARNET, PLUTO, POUNCE, REDLIGHT, and SNOWBIRD), suggesting he classified it as a distinct, non-extraterrestrial operation.
Distinction from other Project GALILEOs
Cooper's Project GALILEO is unrelated to Bob Lazar's Project Galileo — an alleged alien-propulsion reverse-engineering program at S-4, Nevada — though secondary UFO sources have at times falsely conflated the two through confusion with Cooper's separate Project Pounce (crashed-craft recovery) and Lazar's testimony. Lazar described his Project Galileo in 2019 as concerned with "the propulsion system of extraterrestrial and future terrestrial vehicles," with a separate "Project Sidekick" covering weapons applications of the same craft and "Project Looking Glass" covering time distortion effects; no connection exists between this and Cooper's Jupiter-ignition scheme.
A third entirely separate use of the name belongs to The Galileo Project, a Harvard-based mainstream scientific initiative by Avi Loeb to search for extraterrestrial technological artifacts — publicly announced in 2021 and entirely unrelated to either Cooper's or Lazar's program.
Lucifer designation
The designation "LUCIFER" (from Latin lux ferre, "light-bearer") for the proposed new stellar body is interpreted by Cooper as a deliberate Masonic and Luciferian symbolic reference — the creation of a second sun in the solar system fulfilling prophetic expectations held by the secret society leadership he believed controlled the operation. Cooper framed Project GALILEO not as a scientific or climate-engineering programme but as a mystery-religion ritual enacted on a planetary scale, with the plutonium ignition of Jupiter serving as both a practical and symbolic act.
Cooper connected the project to the broader Masonic and occult underpinnings he described in Behold a Pale Horse, where he argued that a network of secret societies — which he called the Brotherhood of the Snake — had embedded itself in the highest levels of government, intelligence, and science, using NASA and classified military programs as instruments of a long-range occult agenda. The deliberate naming of a proposed artificial sun "LUCIFER" was, in Cooper's reading, a declaration of this agenda made in plain sight to initiates within the program.
Scientific context
The ignition of a gas giant through a plutonium detonation is not considered physically feasible by mainstream astrophysics. Jupiter's mass — approximately 1/1000th that of the Sun — falls far short of the threshold (~75–80 Jupiter masses) required for sustained nuclear fusion in a stellar core. The total plutonium aboard the Galileo spacecraft (approximately 49 pounds across its RTGs) is many orders of magnitude below any conceivable ignition threshold. Critics have noted that Cooper's claim appears to rest on a fundamental misunderstanding of stellar physics, though proponents argue the classified science underlying the program may differ substantially from public astrophysics.
Legacy
Cooper's Project GALILEO allegation was circulated widely in UFO and conspiracy literature throughout the 1990s, particularly in connection with NASA's actual deployment of the Galileo probe to Jupiter (launched 1989, arrived 1995). When the Galileo spacecraft was deliberately de-orbited into Jupiter's atmosphere on 21 September 2003 — a manoeuvre conducted to avoid contamination of Europa or Ganymede — some commentators in conspiracy circles interpreted this as the attempted (but failed) execution of Cooper's predicted ignition. The probe was destroyed by atmospheric pressure and heat without any nuclear event.
The LUCIFER designation has since been applied to a real scientific instrument: the Large Binocular Telescope Near-infrared Utility with Camera and Integral Field Unit for Extragalactic Research (LUCIFER), a large binocular telescope infrared instrument installed on Mount Graham, Arizona — which itself became the subject of independent conspiracy allegations regarding Vatican astronomy and the search for incoming objects.