Why Are UAPs Associated With Naval Aviation?

We're more likely to find artifacts from technology-using aliens - self-reproducing (von Neumann) probes - rather than the aliens themselves, or even to recognize and understand their signals against background, if any. Indeed, humans may be just at the technological threshold of building such probes right now, but we're far from any serious discussion of manned interstellar travel, and in fact it may never be biologically feasible. Such objects are likely to be found associated with lower gravity objects, ie the asteroid belt, where they can obtain materials and build more of themselves. The further they are from home, the less likely they are to adhere to some "mission", and the more likely they are to have mutated and been selected merely for fecundity (reproductive ability.) Therefore it's not obvious that they would be particularly interested in finding other examples of intelligence. They could very well be much more interested in finding other von Neumann probes, and humans might therefore not be the most interesting thing in the solar system to them. If this is the situation that obtains, this resolves a contradiction: other technology-using species have indeed appeared before us, but there's little evidence of them here.

If the von Neumann probes are built from metal, and one planet over the last few centuries suddenly has large metal objects moving around its surface (ships) and smaller metal objects moving much faster through the atmosphere - then THOSE might be interesting. You might expect the probes to be especially interested in locations with lots of ship and air traffic, and especially the ones with the fastest air-objects, especially if the fast air-objects come and go from the large metal objects on the surface. It's been observed separately by other writers that, from the standpoint of an off-world but in-solar-system alien observer of Earth's behavior in terms of natural processes, the appearance of metal objects in the atmosphere and then suddenly in orbit is the most interesting phenomenon that has appeared here for many millions of years at least.

The fact that it's US Navy aviators who have reported many of the UAP sightings is obviously relevant. Given that the reported observations are made by multiple modalities (naked eye, radar, thermal) and official US agency reports describe as likely mostly physical objects, it's unlikely these are glitches: that is to say, either they're real, or they're made up, possible as sort of intelligence or misinformation operation that we civilians are caught in. But if it's real, two questions are important to the hypothesis.

First: is there really a higher rate of UAP sightings around US Navy aviation areas (as there seems to be so far, with sightings concentrated around San Diego and Virginia Beach) or is this just bias because there are more instruments and observers there? Such is the frequency of these events according to the reports that a relatively low-budget operation with some weather balloons over a low-traffic area could move the needle on whether naval air stations are "enriched" for these objects. (If it does not make any such observations, it would suggest either it's a misinformation campaign, or they're real but concentrated around naval air stations.) Related: do JFK or LAX have similar sightings? Or Heathrow? Narita?

Second: is it really an American (or mostly American) problem? Is the pattern repeated around the world at other countries' naval air stations? China or Russia might not be interested in sharing this kind of information, but NATO allies might be. That said, if an unfriendly country discloses it is seeing the same thing, and it has no explanation, then it's much more likely that these objects are real, and at least are not human-created phenomena.

Asteroid Bennu is Ejecting Dust; Also, "Alien Tech" on Bennu? (Hint: No)

One solution to the Fermi paradox is that there's evidence around us and we just haven't noticed it yet. An estimate of 20 MA for colonizing the whole Milky Way has been advanced, and if von Neumann probes (VNPs) are possible, then they should be around us. We have a tendency to think of VNPs as industrial-age metal objects like Apollo 11, but organic VNPs could diffuse between low-gravity bodies when interstellar comets or asteroids pass through solar systems. Therefore, when we start finding some interesting high molecular weight organic polymers with non-random monomer sequences in the sample-return specimens from asteroids like Bennu, we should seriously consider that this might be what we're looking at. It is therefore interesting that Bennu is ejecting material (see here and here), which would be required if the VNPs are cellular- or molecular-scale chemical replicators that spread passively.

Here ends the serious part.

Admittedly this is an extraordinary hypothesis, and it requires consistent extraordinary evidence to support it. However, noticing that asteroids have boulders on them isn't extraordinary.

Look! Boulders! And they're circled! Gosh, that MUST be alien tech!
One excitable UFO-hunting schmendrick insisted (after doing a complex analysis in Microsoft Paint, i.e. circling the boulders) that Bennu is "littered with alien tech". Then so is the construction site near my house! So is the desert! There are boulders all OVER the place - my gosh, we're surrounded by alien tech! Run! Apparently skulls have also been spotted. Space pirates? This is a particularly morbid form of pareidolia.

Could Modern Bacteria Seed Early Earth? Could Bacteria in Earth Ejecta Do the Same for Extrasolar Planets?

The C-index is this: how close would we have to be to an identical twin Earth to detect them with our SETI searches, given our current detection technology and our (their) emissions? Many argue that we would identify zero twin Earths this way because to detect them, they'd have to be within 3 LY or so - closer than the closest star.

But this post is asking a different question: if modern archaebacteria were seeded onto Hadean prebiotic Earth (say, an iron-sulfur species like the ones that our best guesses show were the last universal common ancestor of all life on Earth) - would they run rampant and colonize the whole world, or would they collapse, relying on some pre-existing network of metabolites produced by other cells? This is relevant to the question of passive colonization of simple organisms from Earth to nearby stars over arbitrary time scales. Archaebacteria in particular are a concern for NASA in terms of contaminating other planets.

This idea has been floated multiple times, including by astronomer and writer Fred Hoyle. Here is how the process of passive colonization could work. Asteroid impacts are sometimes powerful enough to eject surface material at greater than escape velocity. This is how we have over 100 fragments of Mars on Earth right now. If this happens, some bacteria may survive the initial shock, heat, then freezing and dehydration (some bacteria can survive these conditions; and in any event it doesn't have to be many.) Some of these meteorites will escape Earth orbit. If in vacuum and cold they're stable for arbitrarily long periods, they'll just accumulate in the solar system as septic Earth-meteorites over time. Some percentage of these fragments will interact with a solar system body (e.g. Jupiter) and be accelerated to solar escape velocity (like Oamuamua was in its native system.) Some percentage of those will enter another solar system (this is likely to happen once every 15 billion years, based on calculations inspired by Oamuamua.) Some percentage of these fragments will pass through a solar system with "primitive" planets with a liquid water-CO2 atmosphere like the early Earth. Some percentage of fragments will actually strike those planets, and some percentage of bacteria will make it to the surface intact.

Of course there are many unknowns and I only cited one number. We need to know the bacterial "burden" blasted out of orbit per unit time - none of those in our lifetimes, probably not even Tunguska; the percent chance of survival; the stability over time once frozen (being in solid phase is certainly not absolute protection against radiation). The frequency of planets is roughly known, but not the frequency of terrestrial CO2-water worlds, although reasonable bounds could be placed. As to surviving re-entry, this tends to raise the most eyebrows - but it's worth repeating that roundworms on the Columbia did in fact survive uncontrolled re-entry and were found alive on the ground weeks later. Inside a large iron-silicate rock they may be even better protected.

The most uncertain part of this list of attrition factors is the last one we've now come to, the chance of the bacteria fluorishing on the new planet (lack of metal ions for enzymes, or presence of cyanide, low volcanic activity if we're relying on the iron-sulfur archaebacteria; etc.) But we can start actually filling in the values for passive ("dumb") colonization - the equation to show how fast Fred Hoyle's "lifecloud" and Arrhenius's panspermia would actually occur. Note that this is a different concept from the organic von Neumann probes that could also unintentionally seed life as a side effect, although mechanics would be the same, and we would still be looking on watery low-gravity bodies for evidence of them, like comets and asteroids.

Initially I was tempted to make a stab at setting bounds on 50% chance of colonizing another star, but many of the probabilities would be just guesses. It's clear that this is quite a list of attrition factors, reducing the chance nearly to zero for any one cell or asteroid strike on Earth to seed a future alien ecosystem. But over geologic time there have been quite a few of these strikes, and assuming vacuum-frozen surviving bacteria are stable for a long time (a relative straight-forward thing to test), then the solar system has been slowly filling up with septic asteroids - some of which no doubt have been ejected. So for the near-term, this is unlikely to produce lots of passively seeded worlds, but over arbitrary time, the universe would be accumulating archaebacteria from every place that life evolved. If we think of the Sun as a second-generation main sequence star, then planets of third generation stars are more likely to have been seeded by second-generation ecosystems - and may have more metals available in the ashes of the second generation stars from which they're built.

Other quantitative predictions: a one-third chance of life on Europa.

Interstellar and Intergalactic Panspermia

Active colonization time estimates for the galaxy are invariably much shorter than the lifespan of the galaxy. Passive diffusion would take longer of course but empirically observed Oort cloud mixing intervals even this far from the core for the sun are on the order of 10^5 years. Lingam and Loeb (2018) calculate the delivery of amino acids between star systems but not timescales; still, they estimate an upper bound for the size of interstellar objects for our system (a 10 kilometer-radius asteroid) and Alpha Centauri (an Earth sized planet.) This is a second source pointing to the fact that we may be an interstellar backwater, uniquely un-exposed to evidence of replicators* relative to the stars around us.

Where intergalactic material transfer is concerned, of course given the distances involved we should expect the process to be slower, both in terms of at an absolute rate and moreso in terms of colonizing systems, since the ratio of number of incoming objects:number of systems to receive material will be quite low. That said, a) there are extragalactic stars in the Milky Way right now, and b) we're actually talking about an exponential rather than linear rate if there are replicators* of any sort being introduced. This excludes infrequent but massive events like intergalactic collisions, like those which the Milky Way has undergone repeatedly in the past.

*I deliberately use the term replicators as a catch-all to include "space-viroids" (most likely), von Neumann probes, "cancerous" (mutants selected for fecundity over original function) or otherwise, or deliberate colonizations by agents with some kind of intention (least likely.)

No Radio Signals from Oumuamua

To help rule out Oumuamua as an interstellar probe, it was investigated and found to have no detectable transmissions within 1-10 GHz down to powers of at least 300 milliwatts. Yes, this could be like an uncontacted tribe on Earth in 2018 saying that the drone that surfaced in their bay wasn't sent by people because it didn't give off smoke signals - but you have to start with clear assumptions of SOME kind and test them. That such a ship-like object is passing through the solar system is exciting, but since we found it very soon after we were first capable of finding it suggests that such objects pass through our solar system all the time.

Interstellar Object Oamuamua is Releasing Vapor

A Nature paper by Micheli et al demonstrates that outgassing is one plausible explanation for the subtle changes being measured in Oamuamua's trajectory. It also happens to visually look like a comet, though with much more silicate than organic material on the surface. There's less and less distinction between asteroids and comets - that is, a "primitive" (wet, not-yet-burned-off) body like Ceres is more comet-like than a drier body like Vesta. More here on the (now established) phenomenon of interstellar mixing and what it means, more speculatively, for von Neumann probes and/or the panspermia hypothesis.

Note: I refuse to use the apostrophe for Oamuamua because it misses up alphabetical order, and also, is dumb. Sue me, Hawaiians.

Another Interstellar Asteroid - This One a Permanent Resident of the Solar System

Asteroid BZ interested astronomers right away, because it is retrograde, in a 1:-1 resonance with Jupiter - suggesting that it was captured from outside the solar system just as ours formed, and is therefore older than the rest of the solar system.

But more interesting than that, it took several unlikely events for it to be captured and continue in a stable resonance over time (see last paragraph in the Orbit section.) This very strongly suggests that there are interstellar objects passing through the solar system all the time. For such an object to be captured so quickly, so early in the history of the solar system means that there must be enough of them to get trapped by freak aligments. Another way of looking at it is that fast = likely.

This is consistent with a similar argument made about Oamuamua, an interstellar asteroid that is currently passing rapidly through the solar system. Within a year of the first telescope that could detect such an object being activated, it found such an object. Good luck? Or constant interstellar material passing through? (It didn't take long to find BZ either, once we started looking.) The relevant point is that while the vast distance between stars is often cited as a form of quarantine for macroscale beings like us, it is certainly not such a quarantine, even on brief geological time scales, between pools of organic molecules. More here about periodic close passes between stars and interstellar mixing here and here, and (most speculatively) that if von Neumann probes exist, they are likely to interact with comets and asteroids with organics, rather than planets.

Organics on Ceres Are From Ceres (not from other impacting bodies)

The organic material on Ceres, while intriguing, appears to be native, rather than delivered from other impactors. So says data from the Southwest Research Institute at the 2017 Astronomical Society meeting. The possibility of simple organic replicators on low-gravity bodies in the solar system ("space viruses", to be dramatic) an interesting one, and is one form (or one part) of the pan-spermia hypothesis that's been considered for over a century, going back at least to Arrhenius. (Space viruses might also be the only evidence we would ever see of alien life or even an alien singularity.) What this tells us is that the large majority of material on Ceres, and presumably on most large old asteroids, is native to those bodies since the dawn of the solar system.

What the findings mean for the "space virus" hypothesis is that we can be more confident that Ceres is not crawling with foreign space viruses - although if there is a replicator that can use the typical organics on large asteroids as building materials, that's not what you would usually see. That is to say, when an organism gets infected by a virus, the organism isn't infiltrated with foreign matter, but rather with a tiny bit of foreign matter that then rearranges the atoms in the organism into copies of itself.

Ice on Ceres; Aqueous Chemistry...?

We're increasingly certain that there is ice on Ceres. We've known for a while that Ceres was expected to be more primitive (wetter) than Vesta. I cannot wait for February 2015 when Dawn gets to Ceres.

Good news for possible interesting interstellar chemistry. When are we going to do a sample return mission?!?

Modern Technology and von Neumann Probes: And Again, the Fermi Paradox

Good discussion here of how modern technologies (3D printing) could be applied to building our own self-replicating space probes, which in turn inevitably leads to a Fermi paradox discussion. Replicating probes are the way to go because they cover more territory faster. Authors cited in the article place lower and upper bounds on time to colonize the galaxy with self-replicators from 3.75 to 300 million years. Either way, it's difficult to square an apparently empty galaxy with these numbers, or indeed with the feasibility of such an endeavor. In fact, Frank Tipler (who made the upper bound estimate here) went so far as to argue that this has to mean there are no other intelligent aliens.

This version of the Fermi paradox can be solved by any of these:

- Most likely: they're around, and we haven't looked enough, or don't recognize them, or they avoid us because they're more interested in their own replication than in contacting other intelligent species, for some strange reason. We should expect that any self-replicating probes we find will have undergone natural selection to be primarily good at making copies of themselves, and secondarily at performing whatever mission their initial long-ago designers created them for.

- We're over-optimistic, and self-replicating probes are not feasible.

- These time estimates are not conservative enough.

- We really are the only intelligent species, or at least life is extremely rare.

Proposal: One Way to Find von Neumann Probes

Find their relay stations. Still very much bound by our assumptions about how communications work (and that such probes would care to communicate with each other) but still translates to an actionable plan that can be approached reasonably with current technology.

List of Organic Compounds Found in Sutter's Mill Meteorite

A paper by Pizzarello et al using NMR and mass spec of material extracted from the meteorites has shown many new compounds. I'm always frustrated when papers look at chemistry of extraterrestrial samples and doesn't use basic organic techniques (like NMR) so I was very happy to read this one. Of note, the extraction method used by this team is a new one and more closely resembles conditions on early Earth. The excitement about this paper is that it brings us closer to supporting a panspermia model for the origin of life on Earth. It also supports the idea that meteors (and comets) might actually be harboring some kind of active chemistry - and if we're going to look for von Neumann probes or indeed any replicator chemistry, we should start with the low gravity bodies right here in our solar system. Some of the compounds they found are below:

Pizzarello S, Daviodski S, Hollanda G, Williams L. Processing of meteoritic organic materials as a possible analog of early molecular evolution in planetary environments. Published online before print September 9, 2013, doi: 10.1073/pnas.1309113110.

Asteroids and Comets Exist On A Spectrum

At least some asteroids have an internal reservoir of ice (along with organics); that's the thought for objects like 24 Themis, which retains a high albedo despite being inside the frost line. We also have evidence that centaurs (the outer-system asteroids) are really just relatively close-in comets. Recently a team showed that there are dead comets residing in the asteroid belt among possible dormant ones.

Increasingly it's clear that comets and asteroids are really the same type of objects - mineral objects coated and/or filled with water and sundry organics - with their visual behavior and surface characteristics determined mostly by their position in the solar system. If they've been out at the edge of the system for most of their life and make a sudden close pass to the Sun, they'll lose a lot of water, quite spectacularly. Others (like Vesta) have been stably far enough inside the frost line for long enough that they're dry. For those of us who think the organics we'll find on and inside these objects will be the most interesting thing about them, the limited information we have so far is very frustrating. Consequently I'm more than eager for Dawn to arrive at the much more primitive, wetter Ceres in February 2015.

It's worth emphasizing that we can't be too humble about our level of knowledge about our own solar system. Fuzzy images of Ceres were only compiled by 2007, showing some interesting surface features (craters and a bright spot). That is to say, if aliens had landed on Ceres and made a giant sign with letters 100 miles high insulting us - on the biggest asteroid in our solar system mind you - we would only have finally have noticed it six years ago. I'm not worried that the bright spot will turn out to be a dirty picture drawn on the surface, but it's worth keeping our state of knowledge in mind before we start saying we have no evidence of [fill in the blank] in our solar system.

Close Passes Between Stars, and Cross-Contamination?

Stars move relative to each other, and sometimes they get close. At the moment our closest neighbor is Alpha Centauri, and it's going to get closer. Currently it's 4.3 light year, but 28,000 years from now it'll be just a hair over 3 LY. From the figure below you can see that 40,000 years from now Ross 248 is going to get a little closer than that:


The potential impact of close passes is significant to astronomers, who have already been looking at these events, past and future. Close passing stars are ominously called nemesis stars, since they could cause comet showers, extinction events, and even planetary ejection from a stellar system. It's also interesting from the standpoint of exchange of material between star systems. We know for certain this happens, because the material returned by the Stardust mission from the Wild-2 comet has a different nitrogen isotope ratio then the rest of the solar system - the comet originated from a different star. It's likely this occurred because another star captured a comet with a hyperbolic orbit after it escaped its parent star's gravity, but could this occur by "direct" capture?

You can see from the figure above that there are no close shaves in our future, assuming our surveys have detected all nearby objects* and our proper and radial motion calculations are correct. But there is one coming nearby: in 31,000 years, the Sun's neighbor Epsilon Eridani will be less than 1 LY to Luyten 726-8AB, close enough to disturb a hypothetical Oort cloud around the system, even if not the dust disk around the star; the nemesis will be closer than 1 LY for 4,6000 years. (One of the interesting things about these encounters is that they happen on a scale of thousands of years, pretty fast in comparison to most astronomical events.)

So what are the closest encounters likely to have happened to our neighbors? This paper by Deltorn and Kalas first looked for encounters with Vega, Fomalhaut, and Epsilon Eridani over the past million years, because they have asymmetric debris disks. They found that these stars respectively had 4, 6, and 3 encounters of (at closest) 1.6 LY (no word on how that frequency of encounters compares to other stars with less strange debris disks or no disk at all).

In the course of looking at Hipparcos data for 21,497 nearby stars, they did find an extremely close encounter 350,000 years ago between Alpha Fornacis (HD 20010) and HD 17848, at 0.265 LY. For reference, that's 16521 AU. The comet with the farthest aphelion known is a NEAP-discovered object C/2002_L9, with an aphelion of 14245 AU. There are surely more, so the encounter between the two stars above is surely close enough to capture and therefore exchange material.

The reason this is interesting is that if life exists elsewhere in the universe, and it can move between stellar systems, we're most likely to detect artifacts on low gravity bodies**, especially if they're self-replicating. Comets and small icy moons in our own solar system are a good place to start. Whether what we find are von Neumann probes or space algae is unimportant, and in any event likely indecipherable at first discovery. The same arguments certainly apply to any objects moving under their own power. If these objects are going to move to another system, they're more likely to do it when the two systems are close. This makes a recent finding by Forgan, Papadogiannakis, and Kitching all the more interesting: that using gravity-assist is faster than powered flight alone by two orders of magnitude for galactic exploration, and even adding power to gravity-assist doesn't appreciably speed it along. Their conclusion is that the velocities achieved in their model are still slower than they would need to be in order to say "no aliens have come to the solar system, and if they were around, they would have by now, so there aren't any." (There's more below about the first part of that statement.) This is all to say, if gravity-assist is really the way to go, then it's possible for there to be interstellar "backwaters", where you can't get there from here.

A. Powered	B. Gravity-assist

Powered and gravity-assist models of interstellar travel.
In the gravity-assist model there can be "backwaters"
that are very difficult to get to
If aliens are traveling through the galaxy by powered flight, there's less sensitivity to the distribution of stars, and no sensitivity to starting point: you can turn in any direction you want and travel straight there, and one direction is as good as another. But in a gravity-assist model, there are constrained paths from one star to another. That is, over a few thousand years, you might be able to get to one 20 LY away but you can't get to the one 3 LY away because of your starting point, and the lack of stellar companions or other bodies you might need for your slingshot.

So if it's not just distance, but also the detailed distribution of interstellar geography that matters to the spread of replicator material between star systems (either probes or "living things"), periods of anomalously close contact between stars make a difference. Previous I argued that, to increase our chances of detecting life in other stellar systems, we should look at systems with super-Earths (more gravity therefore thicker atmosphere to preserve simultaneous gas and liquid phases, and more surface area for replicator chemistry to use as reaction vessels); we should also look toward the galactic core - the stars there are older (have had more time for life to evolve) and they're distributed more densely. In addition we should focus on stars that have had close encounters like this, as spreading zones. If it's possible for life to move between systems, it's most likely to move between close systems. Pejoratively, think of it like this: promiscuous stars are the ones most likely to catch something!

So is there anything interesting about the two close-encounter stars? HD 20010 is an F-class star, fairly near at 46 LY from Earth. The system has an IR excess, which means dust. The star is 2.9 billion years old, and is just leaving the main sequence. For comparison, at the corresponding point in the solar system's history, eukaryotes were only just starting to pull ahead of bacteria, but the ancestors of flagellates and ciliates hadn't yet split, and the atmosphere was still only 3% oxygen. Trilobites were still far-future science fiction at that point. The other star HD17848 is now 165 LY from Earth; it's an A-class which also has an infrared excess and therefore dust disk.

Regarding the original three stars in this paper, it turns out Fomalhaut does have a very strange dust ring and a solar system with Earth-like planets.

At this point, strangely dusty planetary systems that have recently been perturbed by near-misses from nemesis stars are best explained by what we already know in astronomy: that there were multiple impact events and the dust is either settling or some non-miraculous process is replenishing the disk. That said, it's still worth paying special attention to "promiscuous" stellar systems for anomalous findings.


*It's risky to assume we've discovered all "nearby" objects. The second and third closest known stars to the solar system were respectively discovered less than a century ago, and this year.

**Detecting extrasolar life by detecting their signals carries far more assumptions than looking for artifacts; for e.g., that they're intelligent, that they use similar technology, that they don't mind being overheard or for some reason want to be overheard by other intelligences, and that, most dubiously, we notice and realize what we're listening to when we detect one. Material artifacts are more likely to be recognizable against background and give the added benefit of proof that transit by replicators between stars is possible.

Meteors Probably Supplied Activated Phosphorus to Early Earth

ATP.

Paper here. This has interesting implications for the von Neumann probe panspermia hypothesis - that is, that there are chemical von Neumann probes (or merely dumb replicators) hitching interstellar rides on small bodies with hyperbolic orbits, and we're a side effect. Consider also that comets delivered most of our water.

Since such a mechanism to build depots for future biochemistry doesn't seem a terribly unlikely occurrence in solar system formation in general, this raises the likelihood of life, but also makes the Fermi paradox (and Great Filter arguments) more exigent.

Evidence of Panspermia in Sri Lankan Meteorite?

That's the claim made by some scientists from Sri Lanka and Wales on material from a witnessed fall, based on elemental content and electron microscopy of structures inside the rock. The problem with these claims is always a) ruling out contamination (the fragments landed in rice paddies) and b) making a claim of life based on electron micrographs.

My question: why do these claims never rely on gas chromatograph or NMR data (for instance)? No, we wouldn't necessarily know what we're looking for, but you'd very likely see some large complex molecules, a few of them much more common than others, and then we wouldn't have another 1996 Martian meteorite false-start. Until then any discussion of space algae is premature. And I even think there will actually be evidence of life (panspermia or von Neumann probes) on asteroids and comets - I just don't think this is evidence thereof.

Aliens and Their Strange Obsession With Intelligence

A staple of science fiction is aliens that are obsessed with locating intelligence, and this is what drives their interactions with humans. What they do when they find intelligence varies. Sometimes they tiptoe around it, desperate for some strange reason to avoid revealing themselves. Sometimes they deliberately enhance it or invite it to achieve some level of enlightenment or at least join some great political organization, as the Firstborn in Clarke's 2001 or the Five Galaxies in David Brin's Uplift Series. But seemingly just as often, they eradicate it, as in the Revelation Space series by Alistair Reynolds or Beford's Galactic Center series.

Why should this be?  Some might be tempted to say, "Well they're intelligent.  And we're intelligent.  We should hang out!"  But this doesn't work well.  First let's get the obvious literary reason for this trope out of the way: these are works of fiction, and aliens in these books are made up because they are interesting for their own sake, and/or because through them we can ask questions about human nature and our perception of reality. Aliens that have no contact with humans aren't literarily useful, and at least on this planet, our intelligence is unique - so intelligence-seeking aliens who come to the solar system will pay attention to us. Among narrative motivations for why aliens seek human intelligence, it also flatters our conception of ourselves, either as grown-up and ready to take our place among the interstellar gods, or as self-flagellation about how we're uniquely nasty and brutish and combined with our intelligence we are a threat to the other peaceful aliens out there.

In reality, either scenario is incredibly unlikely to be true. The history of science is a history of one revelation after another of how we're not special, no matter how badly we would like to be. We're not at the center of the universe, we're not unique among animals, even though for a few biological characteristics we might be near one end of the distribution. (As is likely to be the case for every organism, which are complex entities that have lots of dimensions along which to vary. Sure, we're smart! And sea squirts have the highest vanadium concentrations. So what?)

I'll grant that intelligence may be more important than vanadium, and for the sake of argument, let's assume it's also not invariably an ecosystem-destroying dead end. It's not unreasonable to further assume that aliens we meet in places other than their world of origin got there based on being intelligent. Since we are just prior to our own expansion from Earth (if it ever happens), we are likely to be the stupidest things we encounter. And not just a little stupider. Millions of years stupider. How can I say this? Let's make an an assumption which is too charitable, which is that we only encounter aliens within 1% of our own level of development in terms of how long life has existed on Earth, and that development time correlates with intelligence. 1% ago there weren't even hominids yet. 1% from now, if some descendant of humans is still here, it's likely to be unrecognizably intelligent and powerful. So even with a 1% rule we should assume we'll meet aliens somewhere between as smart as us and 37 million yeasr smarter than us. On average they'll be 17.5 million years smarter than us. Visually:

(For more on this, go here and skip ahead to the second half for the review on McDevitt; also after I posted this, I read something by Michael Shermer which converges on the same argument.) Yes, this also begs the question of whether we know the speed and sequence of alien technological development. Surprise! We don't - so if we're to think about this at all, we should assume we're average.)

All this is to say that there is almost zero chance of meeting aliens just a thousand years smarter. If they're out there, and intelligence is required for space travel, then until we've been around a long time, we should assume they're almost all smarter than us. And getting back to the original question, what would this mean about their taking a special interest in our intelligence? It means there is likely to be none. It seems likely that the information they get from studying or molding the representational tissues in the skull of one species will be about as useful as any number of other biological innovations they could find here. I imagine the pride-wounded humans of the future who make first contact, jealously watching aliens that clearly find sea squirts more worthy of their attention, engaging in various pointless gestures of anger to give the aliens a piece of our mind that of course the aliens don't notice (shaking fists at them, using nuclear weapons, flinging feces - you get the idea.) Assuming we even recognized that they were there in the first place

But there is a benefit to being beneath notice, and that's being beneath notice, notwithstanding unintentional damage caused to us or our ecosystem or planet by their likely-to-be-unpleasant visit. We are highly unlikely to be a real threat, despite the moralizing built into science fiction on this question. (Forget The Day the Earth Stood Still. Arthur C. Clarke's frankly better-left-obscure 3001 contains a particularly cloying moral lesson as he reverses the benevolence of the Firstborn, which decided that we adolescent humans are far too nasty to be allowed to survive. Real aliens are unlikely to behave as such convenient mirrors of our own moral sense.)

Of course, if we kindergartners do somehow turn out to be a threat to the 17.5 millionth graders, we'll never know. There won't be a war, or anything we recognize as an extermination, any more than smallpox understands we deliberately eradicated it.

If any of the assumptions above are falsified, we cannot assume we are the stupidest. For example, if intelligence is not required for interstellar travel - that is, if replicators can evolve and travel between stars without intelligence, we should consider it likely that most extraterrestrial replicators will be space algae. Intelligence requires complex structures, meaning more matter than would otherwise be needed, and is vulnerable to disruption. if alien viruses can get between stars on their own, then there will be a lot more of them traveling back and forth than supergenius alien elephants. (I'm sympathetic to this argument.) If you think intelligence is a dead end, we won't meet intelligent aliens, because they die before they escape their solar system, just like we're about to do.   [Added later:  at least simple organisms can survive getting back down to the bottom of a gravity well without too much protection.  Caenorhabditis elegans worms on the Columbia actually survived the uncontrolled re-entry in 2003.]

It's worth looking at our own planet for concrete examples of how organisms of vastly differing intelligence levels interact. Even as the intellectual giants of our own ecosystem, the amount of contact we have with living things is not determined by those other living things' intelligence, but by other considerations driven by economics. Sure, we might not be as interested in cattle as we are in chimpanzees, but it's hard to say that chimp's lives have been altered by contact with the planet's dominant intelligence to the degree that cattle's have. Applying a similar argument, if our intelligence is useful to them, they'll pay attention. Refer to the development timeline above for why it probably won't be so useful. But that vanadium trick, now that's something!



The Xeelee are super-intelligent aliens from Stephen Baxter's work.  They make things out of galaxies. The things we meet, if we recognize them against background, will be more like this than like us.  And they'll  care about us helpless mortals?  Image rom Steve Burg's blog.

It might also be interesting to take the typical science fiction tropes of alien interest in humans as a given, and ask broadly why this might be. There are two questions that frequently arise in discussions of the simulation argument or Fermi paradox. One is why aliens would bother to trap us, either in a simulation or behind some other barrier that keeps us from spreading outside the solar system. (An ingenious rendering of the latter is the Bubble in Quarantine by Greg Egan.) In general motivations for doing this reduce to we're a threat (see above) or we're in a wilderness preserve or zoo. The second one makes for some neat fiction but it's hard to see why we should give it any credibility as a possible reason for why we don't see aliens or their artifacts or transmissions.

A second question is why uplift-seeking aliens would be concerned with making more intelligence, or accelerating trends. This reflects a larger problem of morality that all of us face in our individual, often misguided searches for "meaning". Morality is a tool that's embedded in the cognition of one particular social animal, so the animal can cooperate with conspecifics to spread its genes. Once that's assured, and it's living in a post-scarcity world, what then? How to live? Is suffering and happiness even meaningful freed from those constraints, and making the world better no longer inherently valuable (because nothing is?) It's possible that there is no way for us savannah apes to answer that question, once morality is taken out of its pre-scarcity context. Maybe then it's game-time, and that's what the Firstborn were up to, where the game is how many other species can you get to join you in Mindspace. But if you just want to fill your now-infinite time with difficult-to-attain goals, it seems that there are infinitely many of them, and elevating intelligence would not have any special luster. And if you think "interfering" in the development of aliens is somehow immoral, what could be worse than running around the universe pushing psycho-evolutionary amphetamines to every near-intelligent organism you find?


The bottom line:

1) If we meet intelligent aliens, they are overwhelmingly likely to be vastly more intelligent than us, and therefore not care at all that we exist, if indeed they notice us.

2) Therefore, if they do pay special attention to Earth or humans for some reason, it is unlikely to be due specifically to our intelligence, despite this being a central draw for alien attention on humans in much of science fiction.

3) If they do pay attention, to our intelligence or otherwise, it is likely that their attention will be very unpleasant, even if this is unintentional.

4) If for some reason we represent a threat, aliens will destroy us. We are unlikely to recognize what is happening let alone be able to fight back.

Sugar Molecules Found Around Young Star

IRAS 16293-2422 is a young binary system, and now carbohydrate molecules - specifically, glycoaldehyde - have been found in the dust around it. What's interesting is a 2005 paper showing higher-than-expected abundance of sulfur-containing molecules; sulfur is important in biology since it is relatively easily oxidized or reduced and can form bridges with itself.

The less speculative reason this is interesting is because it has implications for the evolution of life and the deposition of organic molecules in an early solar system that would make Earth-like life possible. More speculatively, if such things as von Neumann probes exist, these dust clouds around young stars (if common) would be substrate-rich places to reproduce if they're using organics, since they wouldn't have to go down a gravity well or even drill into an asteroid as has been previously discussed.

UV Irradiation of N-Heterocycles Found in Asteroids Forms RNA Subunit

Specifically, uracil, when irradiation occurs in water ice. This is consistent with the nucleobases found on the Murchison meteorite; among the interesting molecules found on comets we can count at least the (simplest) amino acid glycine returned to Earth from Wild-2. More here.

This strengthens the argument for the origin of life by delivery of replicator molecules to the prebiotic Earth by comets and/or meteors (is this even controversial at this point?) but raises the bar on the kind of chemistry we'll need to see on those bodies to believe that we're seeing evidence of replicators from elsewehre, von Neumann probes or otherwise.

Michel Nuevo, Stefanie N. Milam, and Scott A. Sandford. Astrobiology. April 2012, 12(4): 295-314. doi:10.1089/ast.2011.0726.

Cassini Measures Enceladus Chemistry

This past weekend, Cassini sampled the particles in the plumes visible near the south pole of Enceladus. No chemistry results have been released yet, but if we're looking for interstellar replicators (von Neumann probes or otherwise) that build themselves out of common native materials on low gravity bodies, this is exactly the kind of research that's going to start finding interesting results. This is probably my most absurd belief - that there are artifacts of alien technology already here in this solar system, and we're going to find them on wet, low-gravity bodies like comets or Enceladus - but that's why I'm excited to get data that tests this prediction. If all that spray is just cold saltwater, that decreases the chance that we're going to find organic chemistry-based replicators anywhere else outside the Earth's atmosphere - but we already know there are simple organics in the plume, along with higher mass hydrocarbons. I don't know if Cassini's instrument can distinguish between higher mass hydrocarbons or (for example) amino acids, like those found on meteors and comets.

On a side note, this event has gotten amazingly little press outside the science blogosphere: a space craft flew over a moon of Saturn, straight through a water plume from an ice volcano, to sample the chemistry of that water - and indirectly, the probable oceans under the crust. That's pretty incredible.



Above: the Tiger Stripes on Enceladus, where the spray is thought ot originate. Below: the San Francisco Bay Area, from the same altitude (about 115 miles), just because it's cool to compare.