Tomorrow’s “Full Moon” Phase of 3I/ATLAS
In a new paper that was just accepted for publication yesterday (and published here), I reported with Mauro Barbieri that tomorrow, January 22, 2026, the interstellar object 3I/ATLAS will arrive at its rare “full Moon” phase — when observers from Earth will see it from the direction of the Sun to within an extremely small misalignment angle of just 0.69 degrees (0.012 radians). This rare alignment will result in a brightness surge whose magnitude and growth rate could constrain the composition and structure of the particles shed by 3I/ATLAS.
Over the past week, I shared this paper with observers who have access to suitable telescopes with the hope that they will take advantage of this rare alignment of 3I/ATLAS with the Sun-Earth direction.
At solar opposition, the anti-tail jet will be pointing at Earth. The alignment can shed new light — literally speaking — on the nature of the anti-tail and resolve some anomalies (as listed here), such as its unprecedented polarization properties (as reported here and here).
When taking into account the large velocity of 3I/ATLAS relative to the Sun supplemented by the pushback from the solar wind and radiation, the material carried by the anti-tail, including the poisonous cyanide, has no chance of reaching the Earth and affecting our life. The only exception involves technological mini-probes which can maneuver enough to bridge the gap between 3I/ATLAS and the Earth.
The latest anomaly of 3I/ATLAS that might flag a technological signature is the symmetric system of 3 mini-jets that supplement the anti-tail in 24 Hubble images taken over the past couple of months (as discussed here).
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Today, before my morning jog at sunrise I received an uplifting message from my visionary colleague, Dr. Frank Laukien, in reference to my previous essay, titled: “Interstellar Hitchhiking on Objects Like 3I/ATLAS”, posted here:
“Hi Avi,
The large interstellar object (ISO) hitchhiking idea is brilliant, if a technological civilization advances to where it can control propulsion technology for a gentle rendezvous and landing mission with a fast ISO. That’s not such a big stretch even for human technology, as we are not talking about approaching the speed of light — far from it.
Let’s think through this fascinating scenario some more:
The hitchhiking technological civilization would have to almost certainly master fusion technology, with a closed tritium breeding fuel cycle, something also within reach of our technology within decades. Then fuel is nearly inexhaustible.
Being inside a natural ISO has major advantages of camouflage, as you point out, but also of radiation shielding for either some form of biological life, or for electronics that need to last for eons without radiation damage.
While landing on a large, fast ISO is hard, it may be much easier than building such heavy technological megastructures in the orbit of some home exoplanet with otherwise enormous launch costs against the gravity of that exoplanet.
Or maybe an extraterrestrial (ET) civilization catches and modifies a star-bound slower asteroid or comet, or planetesimal, and then keeps accelerating it with hydrogen fuel and fusion energy for hundreds or thousands (or more) of years until it is fast enough to be an ISO?
A large ISO could accommodate biological populations of 10k-100k or perhaps larger populations, even when extrapolating from the size of humans, and much larger if the intelligent aliens are much smaller than humans, e.g., like massive ant colonies. That solves the incestuous genetic degradation and extinction problem of small populations observed on Earth in animals or humans.
However, much smaller biological species may not have the physical or mental capacity and brain size and metabolic energy to evolve into a technological civilization. But who knows?
If it is just non-biological AI on such a technological ISO, size could shrink further, aging would slow way down, and reproduction could be by technological production, but power consumption may go up. Radiative cooling of hot AI chips, or GPU/TPUs in space should be very feasible, given the cold exterior.
Finally, what could be the motivation behind all of this?
Extrapolating from humanity, it may be obvious: the greatest civilizational motivations came from religions, which are not necessarily rational, but mythical, irrational belief systems that keep evolving and are very durable, and long-lived.
Religions or mystical belief systems can lead to enormous technological feats, for irrational religious purposes, like building pyramids or the mysterious stone sculptures of the Easter Islands (and large temples, churches, mosques, and monuments).
So, maybe a potentially technological 3I/ATLAS type ISO is actively pursuing a rational exploration, missionary or conquest task. Or maybe it is just a space monument of an extant or extinct technological civilization that wanted its share of near-immortality or fame or it had a missionary purpose by seeding our galaxy with technological ISOs that can last for billions of years. They could still have active technology on them, e.g., fusion-powered hydrogen propulsion or thrusters, or it could be inactive space archeological objects by now.
But if these are ISO monuments of some distant ET civilizations, why build a few of them so big, rather than seeding with billions or trillions of small ISOs? Perhaps ‘because they could’! The Egyptians built very few, very large pyramids rather than thousands of little ones,
and one large Stonehenge was more impressive than hundreds of little scaled constructs.
Once we do not dogmatically rule out technological explanations, it just opens up our minds to possible scenarios that are fascinating, and some of them seem quite plausible.
3I/ATLAS, even if it turns out to be natural, has already been such an eye-opener, at least for those who dared to look through new conceptual lenses — like you!
Best wishes,
Frank”
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
