Spotted by astronomers last month, interstellar object 3I/ATLAS [NASA] is the third object from beyond that we've detected passing through the solar system. Given that its trajectory does not intersect with Earth's orbit, it "poses no threat to Earth and will remain far away," NASA states. It has been suggested elsewhere, however, that this isn't true if you assume that 3I/ATLAS is in fact a hostile alien spacecraft intent on our death, destruction or assimilation. Bearing in mind Betteridge's Law of Headlines, Avi Loeb's paper Is the Interstellar Object 3I/ATLAS Alien Technology? [Harvard.edu] gets hacking in the dark forest.
At this early stage of its passage through our Solar System, 3I/ATLAS, the recently discovered interstellar interloper, has displayed various anomalous characteristics, determined from photometric and astrometric observations. As largely a pedagogical exercise, in this paper we present additional analysis into the astrodynamics of 3I/ATLAS, and hypothesize that this object could be technological, and possibly hostile as would be expected from the 'Dark Forest' resolution to the 'Fermi Paradox'. We show that 3I/ATLAS approaches surprisingly close to Venus, Mars and Jupiter, with a probability of ≲ 0.005%. Furthermore the low retrograde tilt of 3I/ATLAS's orbital plane to the ecliptic offers various benefits to an Extra-terrestrial Intelligence (ETI), since it allows the object access to our planet with relative impunity. The eclipse by the Sun from Earth of 3I/ATLAS at perihelion, would allow it to conduct a clandestine reverse Solar Oberth Manoeuvre, an optimal high-thrust strategy for interstellar spacecraft to brake and stay bound to the Sun. An optimal intercept of Earth would entail an arrival in late November/early December of 2025, and also, a non-gravitational acceleration of ∼ 5.9 × 10−5 au day−2, normalized at 1 au from the Sun, would indicate an intent to intercept the planet Jupiter, not far off its path, and a strategy to rendezvous with it after perihelion.
It is not Loeb's first rodeo.
Here he outlines two possibilities, one more convincing than the other. First, it's a natural object, an asteroid, and given that it's the third to be spotted in recent years would imply that such objects are abundant. Second, it's a technological artifact send by (or itself) an intelligence. This would explain its unusual orbital dynamics but requires the extaordinary premise of extraterrestrial life and would advance the problem of its hypothetical malevolence. Others possibilities are left to the reader's imagination.
The optimal launch date to send a probe to it was, unfortunately, last July. The best chance to get a close look is apparently Juno, retired in Jupiter orbit, which might have enough gas in the tank to manoever or at least direct imaging devices in the right direction.
My bet: it's a Dyson Tree.
