Anti-Sun Jets in ESA’s JANUS Image of 3I/ATLAS from November 6, 2025
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By UAPResearcher
The radar data from the UAP encounter in November 2025 seems to have sparked quite a bit of conversation lately. I’ve been looking through some of the analysis reports, and there are a few details that stand out regarding object tracking and orbital behavior. It appears that some of these UAPs exhibited flight patterns that defy our current understanding of aerodynamics, raising questions about their origin.
One aspect that caught my attention was the speed at which these objects were detected. The reports indicate that the radar systems in use were able to lock onto the UAPs almost instantly. This capability suggests advancements in our surveillance technology that could significantly impact how we monitor objects in our atmosphere, but it also raises concerns about what else might be flying around undetected.
Additionally, the data suggests that there were multiple UAPs in proximity to each other during the event. This clustering behavior isn’t something we've typically seen in previous encounters. It’s intriguing to think about the implications of objects operating in tandem. Could this point to a coordinated effort or a set of vehicles operating under a unified control?
I also noticed that there was a lack of follow-up from relevant government agencies, which is a bit puzzling given the data's potential importance for space domain awareness. With the increasing number of near-Earth objects, it feels crucial that we have a comprehensive understanding of these UAPs to inform both civilian and governmental monitoring efforts.
What do you all think about the potential for these UAPs to be tied to any known or unknown space programs? It seems like the more we analyze these encounters, the more they challenge our existing frameworks for understanding what is out there. Do you believe the November 2025 data could lead to significant changes in how we approach space surveillance?
As we continue to analyze this incident, I’m curious about what other members have found in their research. Have any of you come across additional documentation or analysis that sheds further light on the radar data and its implications for our understanding of UAPs and orbital tracking? It seems like there’s still a lot to unravel here.
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By Avi Loeb Medium
The symmetric system of three jets emanating from the nucleus of the interstellar object 3I/ATLAS (separately from the primary anti-tail jet) after the circularly symmetric glow was removed by the Larson-Sekanina rotational gradient filter, based on a Hubble Space Telescope image taken on November 30, 2025. (Image credit: T. Scarmato and A. Loeb 2026)A new paper (accessible here) that I co-authored today with Toni Scarmato analyzed images of the interstellar object 3I/ATLAS, taken by the Hubble Space Telescope over the past five months. After removing the circularly-symmetric glow around the nucleus of 3I/ATLAS using the Larson-Sekanina rotational gradient filter, we identified three jets emanating from the nucleus that are equally separated from each other in sky projection by about 120 degrees in addition to a primary anti-tail jet pointed at the Sun.
Whether these jets are technological thrusters or pockets of ice that happened to be oriented symmetrically on the surface of a natural iceberg, the outflows of gas and dust in these three jets exerted thrusts through the rocket effect, which resulted in the observed non-gravitational acceleration of 3I/ATLAS (as summarized in a paper that I co-authored with Valentin Thoss and Andi Burkert, accessible here). Our new paper links, for the first time, the directions and momentum flows in these three jets to the non-gravitational acceleration of 3I/ATLAS.
In our previous paper (accessible here), we demonstrated that the jet system wobbles with a period of 7.2 hours, likely as a result the rotation of the nucleus. We concluded that the jet structure wobbles around the rotation axis with a characteristic angular excursion of about 20 degrees, and the rotation axis is aligned with the sunward direction to within about 20 degrees.
Building on this inferred jet system and periodic wobble analysis of 3I/ATLAS, our new paper measures the observed jet position angles and links them to the non-gravitational acceleration components in three dimensions. We use the sky projection and images of the three persistent jets to estimate the order-of-magnitude thrust that each of them provides to the nucleus. Altogether, our analysis provides consistency between the properties of the three jets and the inferred non-gravitational acceleration of 3I/ATLAS, strengthening the evidence that the rocket effect explains the deviations of its trajectory from the path expected from gravity alone.
We adopted the observed jet position angles (PAs) in the sky (with North=0◦, East=90◦) on November 30, 2025 as follows:
• Jet1: PA = 65◦, • Jet2: PA = 290◦, • Jet3: PA = 175◦.
Our analysis identifies Jet2 as the dominant contributor to the transverse non-gravitational acceleration. The table below shows the breakdown of the contributions from the three jets to the non-gravitational acceleration of 3I/ATLAS, a [with components (A1,A2,A3)], in meters per second squared:
The complete set of Hubble Space Telescope (HST) images is available here.
The symmetric configuration of three jets plus the anti-tail jet raises the question of whether they might constitute a technological system designed for stabilizing the trajectory of 3I/ATLAS. A recent paper by Bo Andree (accessible here) suggested that the
minimal approach for steering an interstellar comet along a controlled trajectory indeed matches this 3+1 jet configuration. By relaxing the full six-degree-of-freedom control to forward-cone steering — sufficient for practical navigation — the paper showed that four thrusters are required: one primary jet and three secondary jets separated symmetrically by 120 degrees from each other. The secondary 3-jets synthesize continuous in-plane steering, while the primary (anti-tail) jet provides low-bandwidth attitude shaping: as the body rotates, the primary-jet torque direction sweeps predictably over a cycle, enabling out-of-plane steering via phase-scheduled firing.
This highlights the fundamental question: is the observed 3+1 jet system around 3I/ATLAS a technological signature?
ABOUT THE AUTHOR
(Image Credit: Chris Michel, National Academy of Sciences, 2023)Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, former director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics (2005–2026), 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.
Professional website:
https://lweb.cfa.harvard.edu/~loeb/
Social media:
https://avi-loeb.medium.com/
https://www.youtube.com/@ProfessorAviLoeb
https://open.spotify.com/show/1zhndXkvSY2b8FdjspFpCd
https://x.com/ProfAviLoeb
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By Avi Loeb Medium
A symmetric structure of three equally-separated jets is apparent near the nucleus of 3I/ATLAS, after applying the Larson-Sekanina rotational gradient filter to two exposures by the Hubble Space Telescope on 2025–12–27 UT. Two of the jets, separated by about 120 degrees, are prominent in both images, but their structure broadens into a wider fan on the right panel. Such morphological changes modulate the amplitude of the brightness variability. (Image Credit: T. Scarmato and A. Loeb 2026)In a new paper (accessible here) that I co-authored with the Italian observer Toni Scarmato, we use images from the Hubble Space Telescope to study the motion of the symmetric system of three jets around the nucleus of the interstellar object 3I/ATLAS.
The Hubble images were processed through a Larson–Sekanina rotational-gradient filter -which removed the circularly symmetric glow around the nucleus. The remaining brightness map shows three close-in jets in addition to a sunward anti-tail on a much larger scale, as discussed in our previous paper here.
These post-perihelion Hubble Images were taken between November 30 and December 27, 2025. The most prominent jet among the three is directed opposite to the Sun and appears to wobble over a period of 7.20 (± 0.05) hours. The total brightness shows contemporaneous variability with a period of 7.136 (±0.001) hours and an amplitude of about 30%. We interpret the characteristic post-perihelion period of about 7.1 hours as an attitude precession or nutation associated with a misalignment of the rotation axis with the symmetry axes of the nucleus. The wobble around the rotation axis displays a characteristic angular excursion of order 20 degrees, while the rotation axis is aligned with the sunward direction to within 20 degrees.
The right panel shows the schematic geometry of the 3-jet system near the nucleus of 3I/ATLAS (excluding the prominent anti-tail outflow towards the Sun), based on the filtered Hubble brightness map on the left. The projected spin axis in the sunward direction appears at a position angle of PA= 110 degrees, and the anti-sunward direction is at PA= 290 degrees. The PAs and oscillation half- amplitudes of the 3 jets are as follows: Jet 1: 55 (± 12.8) degrees; Jet 2 (sunward): 290 (± 20) degrees; Jet 3: 170 (± 12.6) degrees. The anti-sunward jet at PA=290 degrees wobbles with period of 7.2 hours. (Image Credit: T. Scarmato and A. Loeb 2026)Based on the inferred diameter of 2.6 kilometers for the nucleus of 3I/ATLAS (as reported here), only about a percent of the brightness of 3I/ATLAS originates from the reflection of sunlight by its nucleus. When rotation is misaligned with the symmetry axes of the nucleus, it can produce quasi-periodic wobbles and a non-sinusoidal variability. The new analysis links the inferred 7.1-hour period to an attitude precession or nutation of the multi-jet system. The brightness variability tracks transitions between collimated and fan-like morphologies of the jets.
The phase-folded light curve of 3I/ATLAS shows a period of about 7.14 hours. (Image Credit: T. Scarmato and A. Loeb 2026)Whereas the position angle of the most prominent jet shows variability with a period of 7.20 (± 0.05) hours, shorter periods are also apparent. Jets 2 shows a period of 2.9 hours and Jet 3 shows a period of 4.3 hours. The sum of 2.9 plus 4.3 is 7.2 hours.
The phase-folded variability of the position angle of Jet 2 shows a period of about 2.9 hours. (Image Credit: T. Scarmato and A. Loeb 2026)The phase-folded variability of the position angle of Jet 3 shows a period of 4.3 hours. (Image Credit: T. Scarmato and A. Loeb 2026)Summary of the inferred periods in the wobble of the jet system around 3I/ATLAS. (Image Credit: T. Scarmato and A. Loeb 2026)We interpret the ~7.1-hour periodicity as the result of the rotation of 3I/ATLAS being misaligned with the principal symmetry axes of its nucleus. The jet structure undergoes a quasi-periodic wobble as the nucleus exhibits precession and nutation about the rotation axis. This interpretation explains the orientation oscillations of the jets with morphology-dependent amplitudes and phases, the non-sinusoidal variability, and the sensitivity of the lightcurve to evolving collimation (fan opening) of the jets.
Multiple jets in different directions tend to balance each other and stabilize the rotation of 3I/ATLAS. Jet 2 — which is oriented approximately opposite to the Sun and close to the projected rotation axis — anchors the large-scale geometry, whereas Jets 1 and 3 trace the precession cone through their position angle oscillations. The wobble and changing collimation of the jets modulates both the projected jet directions and the total brightness.
The fundamental question that remains unresolved is whether the symmetric triple-jet system is a signature of technological thrusters or the sublimation of natural pockets of ice on the surface of a natural rocky iceberg.
ABOUT THE AUTHOR
(Image Credit: Chris Michel, National Academy of Sciences, 2023)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.
Professional website:
https://lweb.cfa.harvard.edu/~loeb/
Social media:
https://avi-loeb.medium.com/
https://www.youtube.com/@ProfessorAviLoeb
https://open.spotify.com/show/1zhndXkvSY2b8FdjspFpCd
https://x.com/ProfAviLoeb
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Are the Three Mini-Jets, Coming Out of 3I/ATLAS at 120 Degree Separation, a Technological Signature?By Avi Loeb Medium
Brightness maps of the projected jet structure within a distance of 25,000 kilometers from 3I/ATLAS, observed on November 30, December 4, 12, 27 and January 7, 14, 2026 by the Hubble Space Telescope. The image was processed through a Larson-Sekanina Rotational Gradient filter, which removes the circularly symmetric glow around the nucleus. On all these dates, 3I/ATLAS displayed a rotating system of three mini-jets which are equally separated by an angle of 120 degrees from each other. The bottom panel shows the 3 mini-jets along with the 10-times longer anti-tail jet in the sunward direction, as observed on January 14, 2026. (Image credit: Toni Scarmato, based on data released by NASA/ESA/STScI here)Shortly after its perihelion passage on October 29, 2025, the interstellar object 3I/ATLAS was imaged by amateur astronomers to have multiple jets coming out of it (as I discussed here).
The jet structure is best revealed in projected images by applying the Larson-Sekanina Rotational Gradient filter that removes the circularly symmetric glowing halo around the nucleus of 3I/ATLAS.
Applying this filter to 6 images of 3I/ATLAS taken by the Hubble Space Telescope on January 14, 2026 (available here), revealed a symmetric system of 3 mini-jets out to 25,000 kilometers. The 3 mini-jets are separated by 120 degrees from each other in sky projection, and are supplemented by a 4th anti-tail jet extending 10 times farther in the sunward direction.
The 3 symmetric jets appear persistently in the Larson-Sekanina filtering of 24 other images taken by the Hubble Space Telescopes on November 30, December 4, 12, 27, 2025 and January 7, 14, 2026 (as listed here).
Analysis of these images was presented in a new paper that I co-authored with Toni Scarmato , which was posted today here. It demonstrates that the jet structure around 3I/ATLAS wobbles periodically by +/-20 degrees over a period of 7.1 hours. The wobble is likely the result of rotation, with each jet behaving like a misaligned beam from a rotating lighthouse. The rotation axis is oriented surprisingly close (within 10–20 degrees) to the sunward direction, as already inferred back in August 2025 (and reported here).
In another paper that I co-authored with Mauro Barbieri last week (available here), we had shown that on January 22, 2026, the observing direction of 3I/ATLAS from Earth will align to within 0.69 degrees with the anti-sunward direction. During that rare alignment, the rotating configuration of 3 mini-jets might trace a circle in the sky.
My brilliant colleague, Dr. Frank Laukien, noted: “The symmetric 120-degrees angular spacing between the 3 mini-jets is astounding! It is hard to imagine such a symmetry in a natural macroscopic object. A key question is: are three symmetric mini-jets the minimum viable configuration of propulsion devices to re-orient an object in three-dimensional space? Human-made satellite thrusters usually come in pairs on opposing directions. Could the mini-jet geometric arrangement be an indication of active technology? For orthogonal thruster systems, one would need 6 thrusters, with two opposing thrusters along each of the three orthogonal spatial directions. If 3I/ATLAS rotates around its major axis every 7.1 hours or so, then thrusters in the direction of the major axis would not be very useful, and perhaps just (3+1)=4 thrusters in the plane orthogonal to the major rotation axis are sufficient for some sort of technical manipulation like attitude adjustments?”
Indeed, we observe a system of 3 symmetric mini-jets plus 1 major jet. Additional data might help to address Frank’s question. The symmetric jet structure is just one out of 18 anomalies of 3I/ATLAS, as listed here. Identifying one of them as a clear technological signature would boost the rank of 3I/ATLAS high on the Loeb Classification Scale, formulated here, here and here.
Scientific work requires patience, since new knowledge comes one day at a time. Life brings joy when each day teaches us something new. My morning jog at sunrise today was decorated by symmetric fresh snowflakes. There is nothing more invigorating than the beauty of symmetry in nature, both on Earth and in the sky.
A snow-decorated tree along a jogging path at sunrise. (Image credit: Avi Loeb, January 19, 2026)ABOUT THE AUTHOR
(Image Credit: Chris Michel, National Academy of Sciences, 2023)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.
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By Avi Loeb Medium
Images of 3I/ATLAS through 170 second exposures by the WFC3 UVIS (F350LP) camera of the Hubble Space Telescope, processed through the Larson-Sekanina rotation gradient filter, show a double jet structure. The left panel displays the data on December 12, 2025, and the right panel on December 27, 2025. The relative brightness of the two jets changes between these jets, either due to jet rotational wobble or source variability. The brightness is dominated by the anti-tail jet, directed at the Sun towards the lower left side. (Image credit: Toni Scarmato, based on data released by NASA/ESA/STScI here)New images of the interstellar object 3I/ATLAS, taken through 170 second exposures with the WFC3 UVIS (F350LP) camera of the Hubble Space Telescope at a central wavelength of 0.5851 micron on December 12 and 27, 2025, were released here. They reveal a double-jet structure. The more prominent jet is an anti-tail directed towards the Sun.
False-color image of 3I/ATLAS, taken on December 12, 2025 through a 170 second exposure by the WFC3 UVIS (F350LP) camera of the Hubble Space Telescope (top panel), and processed with the Larson-Sekanina gradient filter (bottom panel). The more prominent jet towards the lower left corner is an anti-tail directed at the Sun. (Image credit: NASA/ESA/STScI; Color filter processing: Toni Scarmato)A sunward jet which is 10 times longer than it is wide was already captured in the Hubble image taken on July 21, 2025 (as reported here and analyzed here). Its 7-degree wobble around the rotation axis of 3I/ATLAS (as reported here) implied that it originated near the Sun-facing pole long before perihelion. The gravitational deflection of 3I/ATLAS by the Sun during perihelion on October 29, 2025, was only by 16 degrees, as I calculated here. If the rotation axis did not change orientation between July and December 2025, the original Sun-facing pole is now on the nightside of 3I/ATLAS — opposite to the direction of the Sun. It points in the same direction as the weaker jet in the new Hubble images from December 12 and 27, 2025, and is accompanied by a stronger sunward jet from the opposite side of 3I/ATLAS on its way out of the solar system.
Raw image of 3I/ATLAS on December 27, 2025, taken with a 170 second exposure by the WFC3 UVIS (F350LP) instrument of the Hubble Space Telescope at a central wavelength of 0.5851 micron. (Image credit: NASA/ESA/STScI)Why are two jets displayed in the new images of 3I/ATLAS?
There are two possible interpretations:
1. One possibility is that the two jets are launched from opposite sides of the nucleus. This would make the post-perihelion activity of 3I/ATLAS different than it was before perihelion.
For a natural comet, heat conduction could transport the excess solar energy near perihelion from the dayside to the nightside and activate a weak jet on the nightside in addition to a stronger jet on the dayside.
For a technological object, the sunward jet might be utilized for protection against the solar wind, coronal mass ejections or sunlight — given that the anti-tail is marginally opaque (as discussed here). In addition, the secondary jet could mitigate risk from obstacles lying ahead along its path.
2. The second interpretation is that both jets originate from the Sun-facing side but they have a different composition.
As I described here, the anti-tail jet can extend out to several hundred million kilometers for dust particles with a radius of order 10-micron. However, the sunward outflow would extend only out to a few million kilometers in the sunward direction for sub-micron particles on which the solar radiative deceleration is 10–100 times stronger. A quick turnaround would also apply to gas particles which are swept away by the solar wind or to dust particles with a slow initial speed. All of these particles could therefore turn around quickly and constitute the second jet heading away from the Sun.
The true origin of the jets can be inferred from measurements of the velocity profile of the two jets, based on future spectroscopic data from the Webb telescope. In the second interpretation, the weaker jet would also show a launch base on the sun-facing side of the nucleus and accelerate to an increasing recession speed with distance in the direction away from the Sun. In a technological context, both jets are expected to show a high-speed exceeding 1 kilometer per second at their launch points near the nucleus.
Why do the jets look so different on December 12 and 27, 2025?
Remarkably, the relative brightness and projected shape of the two jets changed significantly between December 12 and 27. This could be a signature of rotational wobble of the two jets, if they are misaligned with the rotation axis of 3I/ATLAS. But the difference could also indicate large variability of the jet sources. A simple way to identify the cause is to compare snapshots taken at different times over the 30-minute observing windows on both dates and identify systematic changes in them. The two Hubble images on December 12 and 27 favor the rotational wobble interpretation — as the anti-tail jet brightens when the opposite jet weakens, as expected from bobble of a double-jet structure around the rotation axis.
As I argued here, the wobble or variability of the jets may explain the “heartbeat” changes observed with a period of 16 hours in the brightness of 3I/ATLAS in July 2025. As a result of mass loss, the rotation period of 3I/ATLAS may have changed by now (as discussed here in the context of the first interstellar object, 1I/`Oumuamua). My team will attempt to measure this possible evolution as we analyze the latest Hubble data on 3I/ATLAS.
Science is exciting, as it offers us an opportunity to learn from new data. The only challenge is that we must stay humble in order to collect new data and learn something new, while self-declared experts provide us with old narratives based on past knowledge.
ABOUT THE AUTHOR
(Image Credit: Chris Michel, National Academy of Sciences, 2023)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.
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