The Aliens Beneath Our Feet

SETI looks outward. The Search for Extraterrestrial Intelligence looks for signals from alien civilizations elsewhere in the universe. The odds are long and the cost is high, but the rewards for success will be great. That search must continue. However, I think we would profit from redirecting a small portion of SETI's money and resources to a much closer and more accessible target: earthly dust. We should be looking down as well as up.

In my short non-fiction book Dust Net, I predicted the advent of nanoscale communication and information-gathering devices the size of dust motes, extremely powerful, and scattered across the earth. These will be developed in the fairly near future for a number of purposes, benign and not so benign. I also speculated that extremely advanced versions of such devices might already be present, deposited on Earth by alien races.

In this essay, I want to expand upon the idea of those alien devices.

Let's assume the existence of a great number of technologically advanced races within a few hundred light years of Earth. That's a very reasonable assumption. Let's further assume that faster-than-light travel isn't possible; that's very probably the case. I think that developing a technologically advanced civilization requires curiosity about the universe and how it works. That implies curiosity about the possibility of intelligent life existing elsewhere, so I think it's reasonable to assume that those advanced races are as curious about life on other worlds as we are.

Those advanced races want to visit other worlds, but distance makes that unfeasible. However, they have the technological ability to send out unmanned interstellar vessels at a reasonable cost — or at least a cost they're willing to pay. What form would those vessels take?

They could be large spacecraft filled with data-gathering sensors, recording devices, artificial intelligence computers, and communications equipment. Since no UFO sightings have been validated, we can assume that if there are such ships, they must not be both large and close, or we would have seen them.

Perhaps the ships have some sort of cloaking technology, or surfaces made of advanced metamaterials, so that we can't see them. However, we watch the skies in numerous and increasing ways, and we watch the earth from above in numerous ways. Before long, we'll be watching the earth constantly from the moon, with increasingly powerful instruments. Before much longer, we'll be looking in all directions from the surface of Mars. No matter how advanced the camouflage of alien ships, the chance of them being detected is already high and will keep getting higher. If they exist, they have successfully avoided detection so far, so they can't be spending more than very brief periods of time anywhere close to the earth. Even at our current stage of detection, they would have to be operating no closer to us than Mars — or at a distance of about 50 million miles (the closest that Mars approaches Earth).

That wouldn't be a problem for them, in some respects. Being able to send complex unmanned probes over interstellar distances requires very highly advanced technology, perhaps advanced enough that it can collect all the data the aliens want even from 50 million miles away. Of course, this would prevent them from collecting physical samples, such as air, water, and bacteria. Even if that were acceptable to them, the data they collected would be fairly coarse. They would not be able to examine our world at a fine and detailed level. The restricted nature of their observations would be frustrating to human scientists and would surely be just as frustrating to alien ones. It would probably be unacceptable, given that they have a much better alternative.

That alternative is what I called Dust Net.

Human beings will create Dust Net in the near future. It will first take the form of simple, microscopic servers scattered around the world to create a communications network accessible to everyone and secure from interference by governments or malicious private interests. With time, these servers will increase in power and will be reduced to nanoscopic size. No bigger than specks of dust, these particles, these motes, will drift with the wind and float on the surface of oceans and lakes, becoming ubiquitous. Their social and political impact will be enormous even before they evolve, as they inevitably will, into instruments of surveillance and data gathering. There will be multiple separate nets, products of governments, corporations, and private groups both good and evil. Mingled among them will be the alien nets.

As I explained in the book, networks of such motes will be able to record immense quantities of data. The advantages for alien observers are obvious. Their motes will be safe from observation or interference. Even without propulsion systems, they will eventually spread everywhere on the surface of Earth. They will gather all the information a curious alien civilization could want.

We are already developing ways for swarms of autonomous drones to cooperate. The much more advanced alien motes are surely capable of cooperating in large enough numbers to, say, dissect an animal corpse for detailed analysis. With sufficient data storage capacity and sufficiently advanced recording devices, they can store a complete digital record of plants and animals, obviating the need for physical samples.

In order for such swarm cooperation to exist, the individual motes have to communicate with each other. Perhaps they use some method of communication that we haven't discovered, meaning that we won't be able to detect them by eavesdropping on their communications. It's also possible that they coordinate their actions only by watching each other, avoiding the need to pass signals. However, if they do communicate, and if they use radio or light signals, that's something we can try to detect. In addition, the swarming behavior itself would make the motes stand out from natural dust.

The advantages of exploration of alien planets by means of such dust motes applies to all advanced alien societies, so if there are such motes on Earth from one alien civilization, there are surely similar networks of motes from other alien societies also present on Earth.

In Dust Net, I speculated that some of the motes created by humans will be designed to destroy other motes. Corporations will do this as a form of industrial espionage. Governments trying to control what information their citizens have access to will try to destroy the motes that provide the access of which the governments disapprove. Eavesdropping motes will expose government secrets, so government motes will try to destroy those. Governments will try to limit observation of their territory by enemy motes, so they'll produce motes capable of identifying and destroying motes from other countries.

All of this exposes the aliens' motes to danger. The aliens must assume that hostile mote networks already exist on the planets they send their motes to investigate. Perhaps the alien motes have the ability to protect themselves, but it would be better if they evaded detection entirely. Therefore, they probably look like inanimate, naturally occurring local dust motes. We could microscopically examine untold numbers of specks of dust and never pick out the alien motes hiding among them.

How do motes from different alien cultures interact? Do they interact at all? I think it's fair to assume that in general, alien civilizations don't need or want to interfere with motes from other alien civilizations. If they can identify each other, they probably leave each other alone. Perhaps some of those civilizations are sufficiently pacific and socially advanced that their motes exchange information with each other. That increases the amount of observational data gathered without extra cost.

On the other hand, there's a good chance that some alien civilizations are located close enough to each other to interact directly, with trade or war. If it's trade, then their mote networks on other worlds, such as ours, are probably designed in advance to cooperate with each other. But if two civilizations are at war, then their mote networks probably are, too. Their motes are here and on other worlds, not for the purpose of gathering interesting data, but in hopes of finding something — science, engineering, weapons — that will give them the edge in the war back home. Their mission therefore includes keeping the other civilization's motes from finding that dangerous information first, so they are designed to identify and destroy each other. As a precautionary tactic, their motes might well be designed to destroy other alien motes, even ones from peaceful civilizations too distant to be a threat. I think that would be our approach if we were those aliens, and it seems reasonable to assume that warring aliens are just as unpleasant as we are when we're at war.

This suggests a way we could detect the alien motes: by looking for the aftermath of battles in the nanoscopic realm.

It's not practical for aggressive alien motes to blast the enemy with destructive rays or cannon shells, so we wouldn't be looking for explosions or tiny bursts of radiation. Such a war is more likely to be conducted at close quarters. Attacking motes act much like predatory insects — injecting the enemy mote with destructive acids or simply tearing it to pieces.

The dead motes should be the object of our search. Those injected with destructive fluids probably still look outwardly just like ordinary dust motes and so are not detectable. Remnants of motes that have been broken apart are a different matter. The attacking motes could take the time to disguise remnants of the enemy to look like just native dust motes, but that's surely impractical just because of numbers. Therefore, if we looked at vast numbers of dust motes, we might be lucky enough to find some of those tiny chunks of disabled technology.

How do the alien motes get to earth? And how do they send their data back home?

One possible answer to both questions is that an alien civilization could produce vast numbers of such motes — say by cannibalizing entire planets to provide the materials — and sending streams of them out in all directions. Interstellar space could be filled with the devices, providing a chain of relay stations to send data back to the home planet. This is obviously excessive.

A far better approach is for the aliens to send out large interstellar ships packed to the brim with fabricators: microscopic factories whose function is to churn out nanoscopic motes. The big ships release fabricators as they pass by stars that have planets. The fabricators drift down to the surfaces of the planets and begin creating motes using materials found onsite. Such fabricators are obvious targets for our own search. They are larger than the motes — microscopic, rather than nanoscopic. And it's hard to disguise them as anything but what they are, because they are emitting streams of newly fabricated motes.

How is the data returned to the aliens' home planet? It seems highly unlikely that an individual mote can send a signal powerful enough to reach another star system. But a huge number of them working in concert can do so. We could detect that.

Perhaps a ship passes by to pick up the signal. That way the signal can be much weaker, possibly below our ability to detect it. However, the passing ship would be detectable. As I argued at the beginning, we can dismiss that idea based on the lack of verified sightings of such ships.

Perhaps small groups of motes, loaded with data and operating as one, can escape Earth's gravity and be picked up by a passing ship at a great enough distance that we can't detect it. We probably wouldn't detect a small clump of motes leaving Earth, either.

Detecting motes through the method they use for returning data to the home planet doesn't seem promising. The other ways I listed above offer a much better chance of detecting the alien motes.

Should we start the search now? It's feasible with existing technology. It will be even more feasible when Dust Net exists. That's probably 20 years away at most, and possibly closer to 10 years. Then we can design motes whose sole job is to examine the dust around them and look for alien motes. Obviously the number of dust specks that could be scanned by using Dust Net, and the number of locations on Earth where the scanning would be done, would far exceed what we can achieve today.

Nonetheless, I don't think we should wait even another 10 or 20 years. The odds against finding alien motes are high with current technology, but the cost would be a fraction of the current outer-directed SETI, and the rewards for actually finding alien motes would be immense.

Unlike SETI, the discoverers won't have to depend on information given to us by aliens, whether intentionally or as a byproduct of their detected broadcasts. With SETI, the information could be significant, or it could be fairly trivial. By contrast, alien motes will be highly advanced alien technology actually in our hands. Given the way the world now works, that alien technology will be the possession, not of the human race, but of the nation that discovered it. The nation that possesses it will leap ahead of the rest of the world in power and dominance even more than the Industrial Revolution vaulted Britain ahead of the pack centuries ago.

This could all be fantasy. The alien motes might not exist. But we can't ignore the possibility that they do. Even now, searching for them would be relatively cheap compared to the cost of SETI and trivial compared to the military budget. The search should begin immediately.