A Plan for SETI

Article by Earthman

The concept of planetary arrays, the artificial packing of orbits with multiple large bodies within the habitable zone of a single star to maximize the available living space of a star system, first emerged in my thoughts while I was working on an article for Extraterrestrial Revolutions #1, an astronomy zine of mine, regarding the possible arrangements of moons and moonlets, moons of moons.It struck me that completing a hexagonal array in a single orbit with alternating larger and smaller bodies of an appropriate mass ratio would create three interleaved trojan arrays in the space of two. Further, I realized, if each of the six equidistant positions, each the same distance from its next in orbit as from the central star, contained two co-orbiting major bodies, akin to Earth and Moon or Pluto and Charon, then twelve major habitable worlds could be arrayed in a single orbit. The distance between partner worlds in the same hexagonal vertex is negligible compared to the distance between vertices.

I have been familiar with the concept of a Dyson sphere for a long time, however, the common solid shell model (see TNG’s “Relics”) initially seemed wonderful, but then I realized it would be terribly wasteful. The amount of material it would take to build a structure designed this way to utilize the entire energy output of a single star would require the available mass of an absurd amount of star systems. An alien culture technologically advanced enough to attempt such a feat would need to sacrifice a significant portion of local space to centralize it all this way. This leads me to think that the amount of energy it would take to construct such a thing would be prohibitive, beyond the waste of thousands upon thousands of worlds closer to habitability as is than after being processed for construction, before construction.

But, then there is the Dyson sphere lite version, a net about a star. You still have the problem of creating night and day cycles inside a sphere whose surface always faces the sun. Again, the natural process of spinning globes in circuloid orbits doesn’t seem so bad as to require reinventing the world.

I also read Larry Niven’s Ringworld in the 70s. Here, instead of a scientific paper, it’s a science fiction novel, and instead of a shell, it’s a ribbon, a ring around a star and night and day are created by an inner ring of alternating blacked out sections and open sections, large revolving curtains. Still, these are astronomical engineering jobs and so, even a thin ring about a star would require the sacrifice of many, many neighboring star systems just to maximize one. And, again, we are reinventing the world, not a globe, but a track.

Still, given enough barren material, any shell or ring model of these types would be an interesting project. It might be better to plan such an effort with a small dwarf star, an M-type star, as the fusion engine of choice. The radius would be significantly smaller than with larger stars, thus,  the amount of material necessary for construction minimized, and the life of the star is far greater than even our sun’s. A properly planned and constructed Dyson sphere wouldn’t be abandoned due to the death of its star for a period equal to several dozen times the current age of the universe.

But then, along came thoughts of planetary arrays and it dawned on me that, if an alien society could move the material to consider constructing anything on the order of worlds or their replacements, then it could probably move the worlds whole and planetary arrays offer a simpler solution to maximizing a star system that doesn’t involve sacrificing anything from any other star system! It strikes me that if life is a test then planetary arrays ace the test.

They also become something to look for in space. Now that we can obtain views of exoplanets, we can start examining the data for signs of planetary arrays. An every-other-pass variance in the dip of a star’s light that’s used in one method of detection could indicate the every-other arrangement of large and small worlds or co-orbital pairs that I suspect are most useful in a Fuller array, my name for the hexagonal planetary arrays I’ve described here and first imagined ten years ago. Could the evidence of astronomical engineering already exist in data we have?

And, since planetary array models can now be used to detect planetary arrays in the data we obtain via space telescopes, such arrays can be considered beacons to civilizations in other parts of the galaxy, maybe beyond. [For strategies in deploying such beacons, see Covert Science: The Series within Covert Science, the zine of science friction from Earthman’s Press.] So, let’s look at some of these models (not to scale): [L stands for Lagrange point, as in L4 = Lagrange point 4; F = “Fuller point”.]

Co-orbital Planets
Not really an array and occurring naturally, usually via collision, still, pairing worlds in a single orbit where they were not previously paired is an astronomical engineering job to consider when and where possible.

Trojan Planets

These might occur naturally. After all, Saturn has two sets of trojan moons where the central moon is a major world. When there aren’t a lot of worlds to work with, this is one option.

The Fuller Planetary Array
I imagine this isn’t likely to occur in nature, but that it may be stable long enough to warrant the effort, perhaps with some station keeping, perhaps with none.

The Full Fuller Planetary Array
Combining co-orbitals with interleaved trojans, we arrive at a 12-world array with all worlds sharing a single orbit in the star’s habitable zone. For dwarf stars one-percent the mass of our sun, the distance between occupied points is one tenth that of the Earth-sun distance (astronomical unit). For stars four times the mass of the sun, the distance between all populated points is 2AU.

The Geometry
Bucky Fuller used similar geometry in designing geodesic domes and tensegrity structures. With that in mind, I coined the term “heliodesy” to describe planetary arrays as belonging to a set of
patterns.

The Natural
Even moving all or many middle, major, or ultra worlds into their own orbits within the habitable zone of the host star when there aren’t many or any there to begin with is an astronomical engineering job worth considering. The goal of planetary arrays is to increase or maximize the habitability of a star system thru rearrangement of bodies in orbit and the nurturing of biomes thereupon thereafter. [For more on the classification of worlds, see ETR and Earthman’s Almanac.]

The work yet to do, besides sifting thru the data on exoplanets for signs of planetary arrays, is to create computer models to test the likelihood of the natural emergence of such arrays and also their longevity. If they are found to be stable for the life of the central star, then they are established as excellent models for astronomical engineering in the future of human endeavors. How we execute such an array is the next problem to solve. If they are found to be unstable after a time, it’s worth considering how much time of stability is enough and then also, how much energy expense is required to keep the station of the bodies thus
arrayed. A little station keeping to achieve long-term stability should not be an impediment to a culture able to move the bodies into position in the first place. If any planetary array model is found to be so unlikely to emerge naturally as to be virtually impossible, but otherwise stable or easily enough stabilized, then we know we have a beacon model. Such an array, if ever observed, would be a clear sign of alien astronomical engineering.If any planetary array model is found to be rare, but not impossible thru natural processes, then we have discovered a pattern that if viable isn’t a clear signal of engineering, but can be a
result of it. Observation of such a system would bear continued observation for other signs of alien presence, but would also offer a target for exploration and settlement if no aliens are ever detected.
Of course, given the vastness of time and our slight presence in it, we may be far more likely to find evidence of a former civilization than a current one. How long does a species that moves
worlds remain tied to them? Still, discovering ancient alien ruins on distant worlds would be extremely exciting and informative. I’d settle for proof of the concept of planetary arrays, but why limit hope? So, if
nothing else, planetary array models give us something to look for and something to look into further if we ever discover them. They provide a means of prioritizing destinations once we’re
capable of choosing from more than the handful of nearest neighbors. They also give us blueprints for future engineering efforts of our own. It’s here that I’m reminded why I chose R. Buckminster Fuller to honor with the naming of the hexagonal array model, for he was one of those visionary pioneers who designed for the future, creating models that couldn’t be built in his time, but are now conceivable projects or will be
soon. He also observed geometry in nature and applied it in engineering to good effect. He also used geometry and engineering to better understand nature and expand human understanding of it here
and there. All these observations went into his life’s work, which was largely covered by his two volumes of Synergetics. My own life’s work, inspired by Fuller and a few others and informed by our now global culture, is in turn largely covered in a compilation in progress, which I call Synergetics 3.0. But, as they emerge, my works have other umbrellas, so, if you are interested in reading more about planetary
arrays as well as interplanetary clocks and calendars, the classification of worlds, even models of cosmogenesis, look for Extraterrestrial Revolutions, the zine, and Earthman’s Almanac. If you
gravitate towards science fiction, check out Covert Science, the zine. If you want to read about models of consciousness, organic information handling, social synergy, and more, look for the zine X Posit.

ETRevolutions.com EarthmansAlmanac.com CovertScience.com EarthmansPress.comEarthmans.net