44 2025.09.24 2025.12.11 2025.12.12 article M. Ljubičić (Amenoum)108. brigade ZNG 43, 35252 Sibinj, Croatia (completerelativity.org)mljubicic99{EAT}gmail.com Extraterrestrials may be involved in some peculiar interstellar and bound comets. general extraterrestrials, interstellar, comets, 3I/ATLAS, 'Oumuamua, Tunguska, Chelyabinsk /authors/Amenoum.html#credits 1 Abstract Is life extraordinary? If not questioned, this assumption is not scientific. Indeed, it appears it has become a circular argument in religious defence of established principles. Genuine science must question the established in order to progress. Period. Here, I question what needs to be questioned - in this context, about peculiar comets. Hypotheses are presented for the involvement of extraterrestrial intelligence in some comets, and even some that have exploded in Earth's atmosphere. Introduction Humans have just started observing interstellar objects and 2 out of 3 confirmed such objects turned out to be very unusual, while the remaining one looked like a typical Solar System comet. The SPHEREx observations of 3I/ATLAS suggest not only that it is unusual, but that it is a large object as well. With the latest data and the assumed albedo (reflectivity) of 5% it should be about 46 km wide. Based on this data, even with an albedo of 100% (mirror), it should still be large, about 10 km in size. Besides the unusual size, this object has an unusually high CO₂/H₂O ratio. But there is one object in the Solar System that has a similar CO₂/H₂O ratio (even a bit higher). That is the C/2016 R2 comet. Interestingly, this comet, with a diameter of ~38 km, may be also similar in size to 3I/ATLAS. Its orbital eccentricity is very high, the aphelion is at a distance of over 1000 AU, and orbital inclination is 58°. Its chemistry is exotic compared to other comets, not just due to enrichment in carbon gases, but also due to unusually high nitrogen concentration. Being an chemical outlier, could C/2016 R2 be a captured interstellar object? Certainly, possibility for such origin has been already suggested by McKay et al. in 2019. But the mainstream is considering that possibility unlikely, as, even though it is unusual, its composition, size and orbit, can be explained through local formation. Therefore, since it can be local it is assumed to be local, and as the assumption is established it tends to be taken as fact, so no other possibilities are further explored - as usually is the case with mainstream. However, its rarity (there are only few similar comets discovered so far in the Solar System) and similarity to 3I/ATLAS does suggest they may have formed in similar conditions (even if not in the same location in space). Now, humans can't send a probe to study 3I/ATLAS (it's too late). With current human technology even sending a probe to study C/2016 R2 is not feasible - given its high aphelion and the fact that it is now on its outbound voyage. But one could send a probe that would wait (at a Lagrange point in space) for similar visitors, intercept them, and then possibly even confirm or refute the proposed formation origins for such bodies. Even if the intercepted comet is bound to Solar System, given the similarity, humans might even learn something about interstellar visitors such as 3I/ATLAS. The ESA actually has a "Comet Interceptor" mission planned for 2029. Sadly, human missions to such bodies are still not designed to look for life or technological signatures. The ESA interceptor probes won't even land on the intercepted comet. Even so, things could get interesting. Discussion, hypotheses Given the large sizes and unusual chemistry of these bodies I'd say there's also a good chance they host some microbiology that may even be activated during close Sun approaches. In any case, it should be clear by now that 3I/ATLAS is a comet, albeit an atypical one. However, its unusual trajectory and size also suggest that it may not be just a comet. Advanced civilizations that want to explore the universe without being detected are likely to use the outer layers of large bodies like 3I/ATLAS and C/2016 R2 as probe camouflage. The probes might be designed to slow down and turn off the engines when they enter a planetary system in order not to look suspicious. Note that the high speed of 3I/ATLAS is unusual even for an interstellar object - it may have slowed down just enough not to be suspicious and then it may slowly accelerate away once out of sight or once the onboard intelligence figures it should be out of reach of the local intelligence (note that 'Oumuamua - which could actually be entirely artificial, has accelerated away from the Sun). Thus, if C/2016 R2 is a captured interstellar body, it too might be something more than just a large piece of rock/dust/ice. So perhaps humans should keep their eyes on it - maybe it won't remain captured. In any case, if it starts speeding up far out there, something's fishy. If there are probes, there could be spaceships as well. A 40 km wide rock could even host a spaceship, not just a probe. But if there are spaceships, they are probably not camouflaged, they are more likely to be simply parked in the outer regions of the system, deciding whether to enter or not based on what the probes record. If the probes are intentionally camouflaged they are also probably completely autonomous and not designed to communicate any information with the mothership while in transit. They could be even lacking propulsion and may be just picked up at some point (space-faring civilizations are probably unlikely to be in a hurry). The probes are also likely to be implanted into rocks in situ. This not only eliminates the need to drag big rocks with spaceships but it makes the probe carrying rocks less suspicious if they are left in bound orbits. Instead of changing trajectories of the rocks, they could be even choosing rocks with suitable trajectories to make things even easier. However, for such visitors a change of trajectory of rocky/icy bodies if need be probably isn't a problem (even humans have done it on smaller scale, albeit not in a particularly sophisticated way). The similarity of 3I/ATLAS to an comet (C/2016 R2) from the outer Solar System combined with its peculiar trajectory goes in favour of this hypothesis. And what about the unusual orbits of other bodies in the outer Solar System? Perhaps the Planet 9 is an spaceship, or both, a spaceship parked on (or inside) a planet. In any case, it makes perfect sense for advanced intelligence to hide - at least the sensitive and vulnerable stuff, from less advanced and potentially hostile intelligence. And humans are a hostile species. However, while they may be camouflaging these probes, the UAP's suggest that some of them are visiting us with less convincing camouflage (although some of us still buy it). Understandably, these too are unwilling to directly communicate with us. Is, however, 3I/ATLAS as big as suggested by SPHEREx? Observations done by Hubble suggest a smaller nucleus, 5.6 km in diameter at most. Since Hubble's resolution is bigger, it seems the smaller estimate for the nucleus size should be more accurate. However, since the two observe bodies in different wavelengths, this is not necessarily the case. Hubble observes bodies in the visible/UV part of the spectrum, while SPHEREx (like JWST) observes in the infrared (thermal) part. So the true size depends on whether the infrared emissions are coming from the released dust/gas or the nucleus. A. Loeb argues that the infrared emissions are more likely reflections from the comet's surface, while the mainstream has basically accepted the estimate from Hubble as fact, ignoring the size estimates based on SPHEREx data. This seems to be a very biased interpretation. Observations in the visible spectrum are strongly dependent on the albedo (surface reflectivity) so if the object seems to have a significantly larger size in infrared it is certainly possible for it to have a lower albedo and, thus, a larger size than what can be inferred from the visible spectrum. However, Loeb's claim is certainly questionable and a lower size is more likely when the dust/gas release is compared to that of the Solar System comets. On the other hand, this is obviously not a typical comet, so it could be larger than assumed even if that seems unlikely. It should be noted that the mainstream is also ignoring the highly unusual trajectory of 3I/ATLAS, as well as the extremely unusual (per the established assumptions on cometary formation) high Ni/Fe ratio (although not unique to this comet). This does not imply that A. Loeb is correct or unbiased, but he seems to be at least less biased. From an unbiased view, the observed trajectory and nickel enrichment coupled with iron deficiency are more easily explained with artificial alteration. It is not only the ratio that is problematic here. The nickel detected is in the form of nickel tetracarbonyl, Ni(CO)₄. This nickel carbonyl is produced by industrial processes but does not occur naturally on Earth and is not expected to be found occurring naturally, although it has been (together with iron pentacarbonyl, Fe(CO)₅) proposed as possible constituent of cometary or interstellar material. But it has never been detected there previously. Carbonyls have been, however, recently detected in a meteorite Lewis Cliff 85311, but in the form of iron cyanocarbonyl complexes, such as Fe(CN)₅(CO), nickel carbonyls were not detected. Therefore, while it is possible that nickel tetracarbonyl exists in comets naturally, from a holistic viewpoint, natural origin should not be a favoured explanation. As for the size of 3I/ATLAS, from the same view, it is a superposition of 46 km and 0.32 km (minimum based on Hubble), so about 23±23 km. 2025.09.27

The latest analysis shows that the mass of 3I/ATLAS must be ≳3.3 × 10¹⁶ g, so its diameter is likely ≳5 km. It could be smaller but not much as that would imply atypical cometary density. The average density of comets is 0.6 g/cm³, which for the obtained mass minimum, gives a minimum diameter of 4.7 km for 3I/ATLAS. Once could argue that the modelling in this study is not very detailed, however, that doesn't imply the results are incorrect, they probably are at least roughly correct. I suggest to anyone who disagrees with the result to do a comprehensive study, however, it seems that mainstream is not interested in that. Some argue that both, the unusual trajectory and size of 3I/ATLAS, are a consequence of detection bias, claiming that surveys usually concentrate on the ecliptic plane and are optimized to search for brighter, larger (kilometer-scale) objects. Sure, it is possible we have missed a lot of smaller/darker objects before the detection of 3I/ATLAS, but one must also consider the time-frame. Detecting a ≳5 km object in 10 years since the start of discoveries of interstellar objects is still unexpected. And does the detection bias argument really stand, considering that the first two objects were far from being aligned with the ecliptic and were both much smaller (<0.5 km). The first object discovered ('Oumuamua) was not only very small (it was probably a disc ~100 m in diameter) but very dark - with no tail or coma. One could argue now that the reason we discovered 'Oumuamua is because it passed close to Earth, but one must now ask - how come we have detected this small dark object but haven't detected any other brighter interstellar objects closer to Earth or aligned with the ecliptic in these 10 years - if we are more likely to detect brighter objects and objects aligned with the ecliptic? The detection bias argument doesn't seem to hold. After all, one could pose the question differently - how come the only interstellar object that passed close to Earth was so dark and so unusual? How come the only object we detected that is aligned with the ecliptic is passing close to Mars, Venus and Jupiter (or, Jupiter moons)? We certainly aren't likely to detect objects with such trajectories more than other ones.
2025.11.10

Turns out my estimate of size centred on 23 km was prophetic. The latest data suggests a diameter of exactly 23 km for 3I/ATLAS, for a CO₂ dominated sublimation. This is a huge blow to the hypotheses of completely natural origin/trajectory. With that said, however, even if 3I/ATLAS is much bigger than what Hubble suggests, the similarity of formation conditions with C/2016 R2 should be questionable. Overall, the 3I/ATLAS may be more similar to 103P/Hartley (a short-range comet) than it is to the long-range C/2016 R2. In any case, involvement of extraterrestrial intelligence should not be dismissed just because the object's characteristics and behaviour can be completely natural. A holistic approach is required to quantify the probability of one or the other possibility. Mainstream generally lacks holism, so it regularly abuses the Occam's razor, which has by now become utterly comical. In order to discover extraterrestrial life one must first allow it to be possible and then investigate that possibility, rather than incorrectly assume (or conclude) the abiotic explanation (no matter how remote) rules it out. Taken together Out of 3 confirmed interstellar visitors, only 1 (2I/Borisov) looked and behaved like a "normal" comet. Maybe it is normal for interstellar objects to look and behave like 1I/'Oumuamua or 3I/ATLAS, but such trajectories shouldn't be normal. Less than 10 years have passed between 'Oumuamua and 3I/ATLAS. 'Oumuamua passed close to Earth and far from Mars and Venus, while 3I/ATLAS is going to pass close to Mars and Venus and far from Earth. Thus, their trajectories are complementary, which is highly desirable if one aims to explore the entire habitable zone of the Solar System and wants to do so using probes implanted into comets. The 3I/ATLAS should also pass close to Jupiter. Considering that gas giants can also have habitable zones about them, this may not be a coincidence either. This suggests that 1I/'Oumuamua and 3I/ATLAS may not be interstellar objects, rather objects whose [previously bound] orbit has been altered by some intelligence. True interstellar objects may be as normal as 2I/Borisov then. Note that the close approaches are at very similar distances - 'Oumuamua passed within 24 million miles of the Sun and its close approach to Earth was at 15 million miles (24 million km). 3I/ATLAS' close approach to Mars will be at 18 million miles (28 million km). 3I/ATLAS will also pass by Venus, but at about 5 times larger distance. From this, assuming these are all cometary probes, one can infer that the targeted distance for close approaches is 20-30 million km (probably close enough for the probes to gather quality data and far enough not to be detected as artificial). Most likely, each probe targets a single body ('Oumuamua => Earth, 3I/ATLAS => Mars). If that's the case, humans may have missed a probe targeting Venus, or perhaps such probe will follow in the near future. Thus, taken together, the trajectories are even more suspicious. The objects may be mostly natural, but their trajectories scream intelligence. Humans have just started looking for interstellar objects and [at least] 2 out of 3 are cometary probes already? Is that coincidence, or life is far from being extraordinary? One explanation for this is that this is ongoing surveillance. Someone out there may be constantly launching probes to monitor the developments in the inner Solar System. How far does it go? While the surveillance may go far into history, the usage of cometary probes for the purpose may be a recent phenomenon, a response to human technological progress. Indeed, a recent study has found unexplained transients near Earth observed prior to 1957 - the year when first human satellite was launched (Sputnik 1). These transients could represent artificial satellites that were used to observe Earth before human technology advanced and humans developed the capability to launch satellites/probes themselves, at which point, or some time prior to that point, the observers switched to cometary probes to avoid detection. If that is the case, someone seems very interested in the developments on Earth and the inner Solar System, and at the same time very careful not to reveal itself. Note, however, that if the switch indeed occurred and the cometary probes were "launched" at natural cometary velocities from the outer Solar System the switch must have been planned in advance. This implies the human development (evolution) is highly predictable (something I have hypothesized elsewhere, and provided evidence for). The observers themselves may have evolved from human-like species. Alternative explanations, however, exist. Perhaps there was no switch, two methods of observation may have been used concurrently all the time, until the usage of local satellites was abandoned. On the other hand, more recent analyses suggest there are tens - if not hundreds - of thousands of highly reflective objects of non-human origin orbiting the Earth, even today. Such high number suggests these may not be probes, rather remnants of probes - perhaps intentionally destroyed before the switch to cometary probes? Another possibility is that this was an cometary probe exploded in Earth's vicinity (in which case, depending how cometary the probe was, apart from highly reflective objects, there should be remnant rocks in similar orbits as well). Could this be correlated with the Tunguska explosion? Potential in the Tunguska-Chelyabinsk correlation Even the more advanced civilizations probably cannot predict the behaviour of comets far into the future. Collisions are always possible. Suppose now that the orbit/trajectory of a cometary probe is altered and it finds itself on a collision course with a planet such as Earth. If the comet has a larger rocky core, some of it could survive the passage through the atmosphere and impact the ground. Obviously, this is not desirable for someone who wants to avoid detection. To account for such cases, in order to minimize the chances of detection, the implanted probe would have to be designed to explode if collision with a planet becomes imminent. However, the collision could be planned as well. Take NASA probes studying outer planets and their moons, such as Juno and Cassini. At the end of service, the Cassini probe was intentionally sent to dive towards the Saturn's surface and disintegrate in the process. Why? This is done not only to dispose the spacecraft (prevent contamination of moons) but valuable data can be gathered during the plunge through the atmosphere. Thus, cometary probes as well could be intentionally sent on a collision course with Earth in order to do close-up observations (and/or prevent contamination and/or dispose evidence of observation). The consensus is that the Tunguska event was caused by a body with a rocky core (50-60 m wide), which exploded in the troposphere. Interestingly, the epicentre of the airburst occurred just offset from the crater centre of a lower Triassic Kulikovksy paleo-volcanic complex that is part of the Siberian igneous province associated with the Permian-Triassic extinction event. Now, it is not uncommon for meteoroids to explode in the atmosphere, and if one considers Tunguska alone, there is no reason to speculate involvement of extraterrestrial intelligence. However, it appears that the Tunguska meteoroid came from the same direction as the Chelyabinsk meteoroid, both exploded over Russia, and Chelyabinsk is the largest impactor since Tunguska. What are the odds for such correlation between the two largest meteoroids to impact Earth's atmosphere in recent times? Note that Tunguska explosion is the largest known such event at least in the last ~3600 years, but possibly more than that as the study providing the evidence for the airburst event near Tall el-Hammam ~3600 years ago was retracted (which does not imply there was no airburst, it just implies the evidence is inconclusive and alternative explanations are possible). Without counting Tall el-Hammam, the most recent similar event (but even stronger) is the Abu Hureyra event in Syria that occurred ~12800 years ago, which is considered to be responsible for the Younger Dryas boundary. But the correlation doesn't even end there. The Tunguska event occurred right about the time when atmospheric CO₂ levels reached 300 ppm, while the Chelyabinsk event occurred right about the time when 400 ppm was reached. Is this a coincidence? I guess humans could find that out for sure when the atmospheric CO₂ reaches 500 ppm (about the year 2040/2041). In my other work, I have argued for the correlation of impacts with CO₂ levels that does not involve extraterrestrial intelligence, but the alternative interpretation is possible (and both are not mutually exclusive). Even though Chelyabinsk impact was notable, it was still significantly smaller than Tunguska, hypothesized Tall el-Hammam was somewhat larger than Tunguska, and the older Abu Hureyra was much larger than Tunguska. It is possible then that the meteoroid impacts are decreasing in strength as the human impact is increasing (or, as the human population is rising?). Based on discoveries in my other works, I wouldn't be surprised by such coupling, but this is uncertain, and older impacts may not be highly correlated with the recent ones. If someone is sending us cometary probes with every 100 ppm of CO₂ increase, is it to tell us something, or is it all for purely scientific/monitoring causes? Interestingly, drawing a line around the globe that passes through the Tunguska site and the Chelyabinsk site passes very close to the Tall el-Hammam and the Abu Hureyra sites, as well. The destruction layer debris at Tall el-Hammam even has a consistent SW-to-NE orientation - thus, along the line, towards Chelyabinsk and Tunguska. Also interesting is that the line passes mostly through largely uninhabited areas (such as Siberia), oceans and deserts (such as Sahara). It passes right between the southern tip of South America and Antarctica, without touching these continents. Seems like strongly populated areas may be avoided, but will the next explosion be along this line as well? And will it be an atmospheric impact (airburst) or a ground impact this time? All of this is, of course, speculation. It could be just a bunch of coincidences. Time will tell. But if the CO₂ correlation is valid, humans might not going to have to wait for long. If the non-populated areas are targeted, it is possible that impacts occur more often - possibly with every 50 ppm increase, humans may have just missed the impact at 350 ppm. Certainly possible if it occurred over the ocean. The unusually large tsunami (for the associated earthquake) that occurred in Nicaragua on the September 1st, 1992 may be correlated with an impact. The Earth should reach 450 ppm about the year 2030, so an impact in year 2029, for example, would significantly increase confidence in the hypothesis, if not, an impact in or about the year 2040/2041 should - or whenever 500 ppm is reached. Interestingly, year 2041 can be extrapolated from the correlation of population size with past impacts, not only from the CO₂, as shown in Table \tbl1.

year	associated impact	population size (millions)	population difference (millions)	magnitude of difference	CO2 (ppm)
~12800 BP	Abu Hureyra	~4	-	-	~210
~3600 BP	Tall el-Hammam*	~54	50	-	~275
1908	Tunguska	~1700	1646	1646 / 50 = 33	300
2015	Chelyabinsk	7300	5600	5600 / 1646 = 3.4	400
~2041	?	9260	1960	1960 / 5600 = 0.35	~500

Table \tbl1: Correlation of impacts, population size and CO₂ levels (* hypothetical) Note that year 2015 was used here instead of 2013 (year of Chelyabinsk impact). While the CO₂ first reached 400 ppm in year 2013, 400 ppm of CO₂ was the average value in 2015, so the year 2015 was used here instead. However, using year 2013 also yields interesting results, as shown in Table \tbl2. The last value for population size was obtained from population difference which was derived from the magnitude of difference - which itself was extrapolated from the progression of past values. This was then matched with the corresponding year (2041) from current UN population projections. Note that, without the hypothetical Tall el-Hammam impact, the correlation with CO₂ (100 ppm quantization) is consistent across all cases (considering the uncertainties, the global atmospheric CO₂ average may have been even equal to 200 ppm at the time of the impact at the beginning of Younger Dryas). Correlation with population size, however, requires the Tall el-Hammam. Table \tbl2 shows the same, but using year 2013 instead of year 2015.

year	associated impact	population size (millions)	population difference (millions)	magnitude of difference	CO2 (ppm)
~12800 BP	Abu Hureyra	~4	-	-	~210
~3600 BP	Tall el-Hammam*	~54	50	-	~275
1908	Tunguska	~1700	1646	1646 / 50 = 33	300
2013	Chelyabinsk	7140	5440	5440 / 1646 = 3.3	400
~2036	?	8935	1795	1795 / 5440 = 0.33	~480

Table \tbl2: Correlation of impacts, population size and CO₂ levels (* hypothetical) What is interesting in this table is the very simple progression of the magnitude of difference (simple division by 10), but the agreement with CO₂ is lower, at least according to projections. It should be noted, however, that the estimates for the population size in 12800 BP and 3600 BP are highly uncertain, which makes the extrapolated correlation of impacts with population size highly uncertain as well. Correlation with CO₂ seems more robust, but again, more data is needed, as the current dataset is simply too small for one to have high confidence in this hypothesis. Conclusion The Occam's razor is easily turned upside down once one realizes that abiogenesis (creation of life from, what are conventionally considered, non-living components) is not an extraordinary phenomenon, rather expected or natural development wherever the conditions allow it. There's actually plenty of evidence that at least microbial life is everywhere, it's just conventionally not interpreted as evidence for life because alternative explanations are possible (and if microbial life is everywhere where it can be, complex life should be everywhere it can be sustained as well). If life is [accepted to be] easy, for a good part of observed chemistry on large celestial bodies the Occam's razor would select microbes, while for the peculiar bodies and trajectories (like 'Oumuamua and 3I/ATLAS), the Occam's razor would select involvement of advanced intelligence. But humans still rather seek complex abiotic explanations because life is still conveniently assumed to be hard so they can remain special. Well, I'm pretty sure we're not, and one of these days humanity will have to get over it and mature, or get extinct probably.