Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm


18.7  Climate Modification and High Technology Weapons

The science of weather modification and climate control is still in its infancy. It is therefore much more difficult to assess the possibilities than in earlier "High technology" necessarily implies a more speculative effort -- not to imply that weapons discussed below are any less dangerous or less real. If any of the techniques described below turn out to be unworkable for one reason or another, it’s probably unimportant. The ETs undoubtedly have far more effective ones at their disposal!

Dr. Pierre St. Amand, doing weather modification research for the U.S. Navy in the mid-1960's, said of his work: "We regard the weather as a weapon. Anything one can use to get his way is a weapon and the weather is as good a one as any."547 In 1974, the Pentagon conceded it had used weather warfare in Vietnam for more than seven years. In point of fact, the CIA allegedly began a rainmaking project over Saigon as early as 1963.471 This disclosure infuriated the Soviets, who promptly introduced a resolution in the United Nations calling for multilateral renouncement of all geophysical and meteorological warfare.462

Man has been tampering with the weather in earnest since Schaefer and Langmuir's historic snowfall-induction experiments in 1946. Unfortunately, there have been many failures and progress has been slow. Silver iodide and dry ice have been used to precipitate rain for decades, and recently another technique -- liquid propane sprayed into supercooled fogs -- has been added to the list.465 Hail suppression research appears promising,464 and snowfall-induction for watershed and recreational purposes has become a commercial enterprise.474 We can disperse fogs, prevent frost, and the NOAA's Project Stormfury has had limited success in reducing the severity of tropical hurricanes. But man’s best efforts to date still appear rather feeble.

Could aliens find ways to generate earthquakes at will? Small tremors have already been artificially created by pumping water into the ground under pressure. This lubricates the fault lines, allowing the crustal plates to slip. Another technique is to set off high explosives at a weak point along a fault, jarring it loose suddenly. If the blast site were judiciously selected by alien geophysicists, the resulting quake could be devastating. Finally, there is the suggestion that earthquakes might be triggered by high intensity infrasound. It is well known that microseisms occur regularly at frequencies around 0.1 Hz,628 and the possibility exists that sympathetic resonances of some kind could be set up. Such oscillations could perhaps be induced using sonic booms. Researchers have discovered that infrasonic energy can be transmitted from the air to the ground; they have detected "air-coupled seismic waves resulting from fighter planes -- flying at high altitudes at Mach numbers greater than 1.2. Such waves have also been detected in the ground below the paths of jet-air liners."628

The average house-rattling earthquake liberates a total energy equivalent to hundreds of gigatons (about 1021 joules). Hurricanes are of similar intensity. But these cannot simply be "triggered" as can quakes, so we‘re faced with a much larger problem in trying to generate one. Tornadoes, the smaller cousin of the tropical hurricane, may be slightly easier to manage. D. S. Halacy, Jr., in The Weather Changers, notes that "there is evidence that a strong air temperature inversion at about 2 kilometers altitude is likely to produce tornadoes."547 Assuming such conditions exist in rudimentary form, can a cyclonic disturbance be generated?

Perhaps. Again, the sonic boom is our instrumentality. An aircraft flying at supersonic speeds, presenting an area of several square meters of fuselage to the onrushing atmosphere, can produce pressures equivalent to "an instantaneous 180-mph hurricane" over a swath a few hundred meters wide beneath it.524 It’s possible that a rapidly circling fleet of supersonic flying machines could induce cyclonic motion in the already unstable air.

Bernard Vonnegut, a General Electric weather modification scientist, notes that a typical tornado funnel is kept going by a power consumption of roughly 200,000 megawatts.547 Could such a tornado be dispersed? That is, have we a defense if the ETs shoot tornadoes at our cities?

A decade or two ago, it was suggested that a "weather bomb" could be exploded in or near a twister, literally blowing it out. This idea has been used in science fiction stories,683 but, as Halacy says: "Recent studies of the power involved in a typical tornado indicate that an H-bomb would be needed."547 Perhaps the cure is worse than the illness! What about generating huge tsunamis, popularly known as "tidal waves"? Tsunamis are generally caused by seaquakes on the ocean floor, and some of the techniques described for earthquake generation might be applicable here. Seismic sea waves have been sighted as high as 30 meters on many occasions, and there are reports of a 50 meter wave following the great Krakatoa volcanic eruption in 1883. The Guinness Book of World Records lists a record wave at 67 meters which supposedly appeared off the coast of Valdez, southwest Alaska in 1964,360 but there are reports in reputable journals of still higher crests.684

Other techniques for generating tidal waves have been suggested, such as the detonation of a one-gigaton thermonuclear device submerged a few kilometers under the ocean surface. This would produce a wave nearly 30 meters high. But the most ingenious idea is the planetoid attack.

Meteoroids pass close to Earth all the time. For instance, on 30 October 1937, Hermes (a small planetoid about one kilometer in diameter) passed within 800,000 kilometers -- about twice the distance to the Moon.563 The Apollo planetoids pass as close as a few million kilometers on a regular basis. These objects range from a few kilometers to as large as thirty kilometers in diameter. It is estimated that the Earth has been struck by one of these larger meteoroids about once every few hundred million years.598 If the aliens were able to latch onto one such chunk of rock and iron, a few well-placed H-bombs could alter its trajectory very slightly -- just enough to nudge it into a collision course with Earth.

If a planetoid one kilometer in radius were to strike our planet, it would gouge out a trench 80 kilometers in length and at least eight kilometers deep -- more than four times as deep as the Grand Canyon.414 But the surface of our planet is mostly water, so a sea landing is more likely. What if the object were to strike an ocean (Table 18.5)? Oceanographers have calculated that such an impact in, say, the central part of the Atlantic Ocean, would initially form a transient rim crater -- a monstrous wall of water -- on the order of three to six kilometers high.596


Table 18.5 Seismic Wave Heights for Planetoid Oceanic Impact*
(mean impact velocity 10 km/sec)
Seismic Wave Heights 
Diameter of Planetoid
Energy Released on Impact**
5 meters
100 meters
23 megatons
10 meters
200 meters
190 megatons
40 meters
500 meters
3 gigatons
100 meters
1 kilometer
23 gigatons
250 meters
2 kilometers
190 gigatons

*Adapted from tables and equations,504 assuming planetoid density r ~ 5 gm/cm3
**One megaton = 5.76 x 1015 joules


What about planetary flooding? Astronomer Stephen H. Dole has estimated that a multiplication of the terrestrial water supply by a factor of four would be required for complete inundation of all the continents.214 Where might aliens find this much water?

Not on Earth, certainly! One old idea is the atmospheric precipitator, a device capable of precipitating out all the water held in the humid. atmosphere. However, simple calculations reveal that if all the liquid in our skies were suddenly condensed, we‘d be standing ankle deep in water. It’s possible that highly localized flooding could occur, but a widespread terrestrial deluge is quite impossible using this technique.

Perhaps ETs could melt the polar icecaps. The two icecaps contain a total of 23 million cubic kilometers of ice.367 With all this water, the absolute sea level will rise only about fifty meters, leaving most of Earth’s surface high and dry. Unfortunately, many of the world’s most populous cities are located near the coast. Dr. Howard A. Wilcox in Hothouse Earth has shown that 33 of the 50 largest metropolitan areas on Earth would probably be inundated. This would displace about 71% of the population of those 50 cities alone -- some 200 million humans.688

Wilcox suggests that icecap melting may occur naturally if mankind continues to increase its worldwide energy consumption exponentially. But we are concerned here with the possibility of aliens purposefully thawing the poles. Halacy relates that the Russians have experimented with in creasing the melting rate of snow.547 This is accomplished by dusting the surface with lampblack, causing the ice to absorb solar heat more rapidly and melt. Halacy estimates that to spread a film of carbon black one-tenth of a millimeter thick over the entire northern polar region would require nearly two billion tons of the stuff. A fleet of 1000 B-52H bombers would require 50,000 missions to complete the dispersal. This technique clearly leaves much to be desired.

Could nuclear devices be used to melt the icecaps? The energy equivalent required for this feat is roughly one billion megatons. If the ETs have this kind of firepower available, why should they bother melting ice with it?

As Robert Frost agonized over the decision of whether to die by fire or ice, let us now consider a weapon that could cause an ice age to occur on Earth. It has been suggested that clouds of particles be circulated in an interior solar orbit, or giant sheets of reflective foil interposed between Sun and Earth, thus causing our planet to cool rapidly. If the Sun’s rays were suddenly cut off, the atmosphere would cool to freezing, the approximate temperature of the ocean, in a matter of days. From then on, the temperatures would drop much more slowly, since the huge volume of the ocean would act as a giant thermal buffer. However, it is believed that the Ice Ages were brought about by temperature changes as small as 10 °C. We could be in big trouble in very short order.

Neither of the above proposals is workable, however. Thermal agitation and the solar wind would rapidly disperse the orbital gas cloud (or the foil), and a few warhead-tipped missiles strategically detonated would probably be enough to wreck the entire scheme.

The best way to artificially cool a planet is to disperse fine dust throughout its atmosphere, way up in the stratosphere above the rain clouds. This elevates the planetary albedo, causing solar radiation to be reflected back into space. The planet will begin to cool.

Using particles with diameters of 0.01-0.1 microns, an effective job could probably be done with about 20 million metric tons of the stuff. If the aliens build a linear induction catapult on the lunar surface, and each shipment from the hypothetical ET Moon colony contains about ten cubic meters of fine dust, it would take about one year to blot out our sunlight if they send off one parcel every minute! There are two great advantages to this weapon -- from the aliens‘ point of view. First, the cooling is probably irreversible and would precipitate an Ice Age on Earth. Second, there is virtually no defense against its use, as it would be impossible to scoop out dust dispersed randomly throughout our atmosphere as fast as the ETs could dump it in.685 About the only alternative to surrender would be a direct frontal assault on the Moon colony.

There are other devious tricks the aliens could attempt with our aerosphere. As noted earlier, exposure to ultraviolet radiation can cause skin cancer, severe burns, and "snow blindness." The Sun puts out lots of UV, but these rays never reach the Earth’s surface. This is because the natural protective ozone layer generated by the atmospheric oxygen screens them out. Ozone is present everywhere in our air, but most of it is concentrated in the stratosphere at an altitude of about 20-30 kilometers. If we could collect all the ozone from a column of air stretching from the ground to the borders of space, we‘d find that each square meter has only about four grams of this precious allotrope of oxygen above it. Were we to completely destroy this protective chemical layer, about 64 watts per square meter of harmful ultraviolet radiation would pelt us from the sky.

Aliens may decide to try to relieve our atmosphere of its ozone. Nitrogen oxides, SST emissions, fluorocarbons and other industrial aerosols are already beginning to do a fine job of this, but the ETs undoubtedly will want to hurry matters along. How might they go about the construction of a deozonification weapon?

Dr. Michael B. McElroy, professor of Atmospheric Sciences at the Center for Earth and Planetary Physics at Harvard University, has intimated that bromine is so effective at destroying ozone that "it could be used militarily."414 Any halogen will do, but apparently the brownish-orange liquid element, acting as a catalyst to decompose the ozone back into oxygen, does it best. Each halogenic atom injected into the stratosphere can theoretically catalyze as many as a thousand reactions before it becomes chemically locked in a relatively inert form.520 A simple calculation demonstrates that approximately four kilograms of bromine, dispersed in the stratosphere over each square kilometer of the Earth’s surface, will result in virtually total deozonification.

To deozonify the entire world would require about two million metric tons of liquid bromine.* The supply officer at Dow Chemical Corporation in Walnut Creek, California tells me that the aliens can purchase liquid bromine from him for 30¢ a gallon -- provided they buy in 2300 gallon tank car lots. This works out to about $52 million -- not counting the cost of delivery to the stratosphere -- for eliminating our planet’s ozone screen. Studies show that anyone exposed to the downpour of ultraviolet radiation for more than a minute would receive severe second degree burns, and would be blinded in seconds should he cast his eyes skyward.417 Terrestrial flora would begin to perish within hours.445

There are several other highly speculative "high technology" weapons. These weapons are wholly infeasible using existing human technology -- but of course this doesn‘t restrict the aliens, who are all the more delighted at our lack of efficacious defenses.

Dr. Horace Dudley suggests that it may be possible to induce a runaway chain reaction in our atmosphere. He says that if a large enough nuclear device were detonated in open air, a worldwide conflagration might result.457 Although many would scoff at this idea, apparently Compton himself once performed a calculation to estimate the likelihood of such an event. The result? A small, but non-zero, probability.

We may someday find ourselves attacked by a giant "doomsday machine." Such a possibility was explored in a Star Trek adventure of the same name. A giant robot "planet-killer" was roaming the galaxy, chopping whole planets into rubble with antiparticle beams and stoking its nuclear fires with light elements extracted from the debris. Our only defenses would be ingenuity and luck.

Black holes, if you believe they exist, could even be used against us. Quantum black holes may exist, holes with relatively small masses and unimaginable densities. Theoretical physicists such as Dr. Stephen W. Hawking of Cal Tech (currently Cambridge University) have calculated that quantum holes with masses greater than about a billion tons will not have evaporated yet. If such a hole was to become trapped by a planet, it would slowly "digest" the body, eventually resulting in a slightly larger quantum hole -- and no planet.686

But if not the planet, then perhaps its sun. Niven and Pournelle have suggested, in the fictional The Mote in God’s Eye, that if asteroids are shot into a star, their sudden vaporization may cause severe instabilities leading to an explosion of the sun itself.668 But the "classic" technique, which is discussed at greater length in the following chapter, is Shklovskii’s ten billion megawatt graser.3 Supposedly, it could induce a powerful Type II supernova in any metal rich star greater than about five solar masses. Hence, using this scheme, Sol could not be detonated. How ever, there are at least 200 supernovable stars within 100 light years of Earth, the distance of minimum biological effect for supernovae.468,469,498 As technologist Adrian Berry remarks of this weapon: "Blowing up the sun... would be a perfect Götterdammerung for a besieged warlord. It would be a spectacle to surpass all others; but the fact that nobody would survive to witness the effects might, paradoxically, make the action even more attractive to warped or highly 'poetic' minds."77

Still worse, the aliens could commit galacticide. Near the Galactic Core, stars are much more densely packed than out here near the rim. In more than one science fiction tale, a supernova occurring in the Core initiates a chain reaction of stellar explosions, spreading outward in a spherical wave at the speed of light. The entire Galaxy is doomed!687,607


* Between 1961 and 1971, the U.S. military dropped nearly 50,000 metric tons of herbicides on the forests of Vietnam. This represents about 2% of the mass of bromine the ETs would have to use to deozonify the Earth.


Last updated on 6 December 2008