Paper: Is the Interstellar Object 3I/ATLAS Alien Technology?

[thorbiorn]

My only comment is , what a joke NASA is.

NASA is probably like the CDC in some respects. Maybe they have been asked to keep people a bit more in the dark, or continue to do so. They can't afford to get too far ahead of themselves compared to the drone investigations, blurry UPA pictures, Charlie Kirk murder, the Epstein files, Ukraine project, Gaza support, and who knows comet cluster and Sun twin.

I found a Russian channel, Astro Channel, auto dubbed into English, with an amateur who went out to take his own pictures in some mountains 1700 m above sea level.

When comparing Nov 11 with Nov 18 he proposes that the comet has broken up. Whether that is true or it is just an optical effect due to a jet from one part, I don't know, but you can see the image here, and zoom in if you like.

 

[Gaby]

When comparing Nov 11 with Nov 18 he proposes that the comet has broken up. Whether that is true or it is just an optical effect due to a jet from one part, I don't know, but you can see the image here, and zoom in if you like.

Very unlikely. It looks like a star behind it. I think the Cs are right, the comet nucleus is greater than what they say, more like 8 km and possibly growing. Otherwise, it would have disintegrated as a result of the various X flares it discharged from the sun and which hit the comet directly.

And there are spectroscopic results from that time period. They were done in the Physical Research Laboratory in Mt Abu Observatory. Here are the results:

ATel #17502: Comet 3I/ATLAS: Post-perihelion spectroscopic results from PRL Mt Abu Observatory

www.astronomerstelegram.org

Comet 3I/ATLAS: Post-perihelion spectroscopic results from PRL Mt Abu Observatory

Shashikiran Ganesh (PRL), Goldy Ahuja (PRL), Arvind B.(PRL,), Anil Bhardwaj(PRL)

on 19 Nov 2025; 16:03 UT

Observations of the comet 3I/ATLAS, also known as C/2025 N1 (ATLAS), were obtained using the instruments on PRL's 1.2m telescope at the Mount Abu Observatory during November 12 to 17 in the late hours of the night, just before dawn. Initially, when the comet was visible for only a short time, observations were carried out using an imager in the R filter (see false colour image in the online link below).

On the later nights, we carried out spectroscopic observations on the PRL 1.2m telescope. The observations were conducted using the LISA instrument, which provides spectral coverage from 3800 to 6800 Å. At the time of observation, the comet was at a heliocentric distance of around 1.51-1.53 AU and a geocentric distance of 2.08 - 2.05 AU. The slit was placed on the photocenter of the coma of the rare interstellar object, and exposures of 15 minutes were obtained with the telescope following the fast-moving object in non-sidereal tracking mode. The spectrum was extracted using a rectangular aperture of 32.60 × 1.76 arcseconds, corresponding to approximately 48707 km × 2617 km on the coma. The spectrum was flux-calibrated and solar continuum corrected to remove the dust contribution. The spectra show typical emission lines and bands from CN, C2 and C3, as are also usually seen in Solar system comets. The spectra are available in the link below.

To our knowledge, these are the first post-perihelion spectra of Comet 3I/ATLAS. The spectra show it to be a comet similar to those belonging to the Solar System. Our value for the log(C2 / CN) production rate ratio is approximately -0.73 (observation of November 16, 2025), which indicates the comet to be similar to the depleted class of comets of the solar system in terms of carbon composition. Observations with longer exposure times will help confirm the production rates and ratios.

We are conducting further observations with PRL's Mount Abu telescopes and encourage continued monitoring of 3I in the days to come.

Work at the Physical Research Laboratory is supported by the Department of Space, Govt. of India.

C/2025 N1 or 3I/ATLAS ATel

Figures to accompany the ATel on Comet 3I/ATLAS - observations from 1.2m telescope at PRL Mt Abu Observatory False colour representation of an R band image of Comet 3I/ATLAS using PRL Imager on 1.2m Mt Abu Telescope - November 12, 2025 LISA spectrum of 3I/ATLAS on November ...

docs.google.com

 

[Gaby]

I think the Cs are right, the comet nucleus is greater than what they say, more like 8 km and possibly growing.

Ok, might be the reason none of the big telescopes wants to take a high definition picture of it.

From xras

Photograph: Julien de Winter, November 25, 2025 (https://app.astrobin.com/i/jtmq82 ).

Notice how the tail is less spectacular, but the body is pretty intense, with a sunward spike. That can be expected from a very fast moving comet with a highly eccentric orbit.

xras

3I/ATLAS lowers brightness despite getting closer to Earth

The brightness of the 3I/ATLAS object has decreased quite noticeably over the past few days, by more than a third, when observed from Earth, despite the fact that the celestial body continues to rapidly approach the planet. The magnitude (the main characteristic of the brightness of celestial bodies), which was 10.1 at the beginning of the week, has increased, based on recent observations, to 10.6, which means that the brightness of the body is now about 63% of what it was 6 days ago. Since the distance between the object and the Earth has decreased by 10 million kilometers during this time, the main reason for the decrease in brightness is probably the continued distance of the body from the Sun. Since an object classified as a comet should shine with the reflected light of the Sun, as the distance from the latter increases, the brightness of the body should also decrease. At least, this explanation looks quite natural.

However, it is possible that the decrease in brightness is also influenced by internal causes, for example, changes in the characteristics of the central body that are hidden from observation and affect its albedo. Despite the decrease in brightness, 3I/ATLAS continues to occupy a fairly high, 4th place in brightness, among almost 100 comets currently in the Earth's sky and available for observation. At the same time, comet C/2025 A6 (Lemmon), which has already been partially forgotten and dropped out of the news, continues to be in the first place, the luminosity of which has decreased by almost 10 times over the past month, but still remains at a high level. As for 3I/ATLAS, its current brightness values keep it accessible not only to scientific, but also to semi-professional instruments.

The incoming images (one of which is attached to the message) show, in particular, a very unusual "ragged" structure and dynamics of the tail of the object at the moment. One of the main intrigues at the moment is whether NASA will decide to turn its two most powerful instruments, the Hubble and James Webb telescopes, to 3I/ATLAS. Both devices have already captured the object, but several months ago and at a noticeably greater distance from the Sun than it is passing now. Technically, such an opportunity should be provided in the next 2-3 weeks: the distance of the object from the Sun will be large enough so that its images can be taken without the risk of damage to the most expensive space instruments in the history of mankind. So far, however, NASA has not given any clear comments on this matter.

 

[thorbiorn]

Comet 3I/ATLAS: Post-perihelion spectroscopic results from PRL Mt Abu Observatory

The Mount Abu InfraRed Observatory (MIRO) is located near the town Mount Abu in the state of Rajasthan, India. The observatory is at an altitude of 1680 metres and is adjacent to Guru Shikhar, highest peak of the Aravalli Range. The 1.2 m infrared telescope at It is the first major facility in India specifically designed for ground-based, infrared observations of celestial objects. Further the low amount of precipitable water vapour (1–2 mm during winter) at Guru Shikhar makes it a good site for the infrared telescope observations. The site has been found to be good (about 150 cloud free nights per year) for astronomical observations.

India can do what NASA can't or won't.

Ok, might be the reason none of the big telescopes wants to take a high definition picture of it.

The telescopes might be busy, I imagine they are booked long in advance by researchers busy writing the papers they have to write to keep their jobs, or some trying to do their ph.D. Maybe some are looking into black holes or trying to find out what came before the big bang?

Going through the lists, there have been several larger ones comets among those that have been calculated:
From List of periodic comets
Before 2000 there is one with 9.1 km
2000s, there is one about 10 km
2010s there is one about 21 km
2020s there is one with 0.31-0.50 km
For many of the comets there are no estimates.
From List of long-period comets
19th century, one of 29.65 km, one of 24.75 km
20th century, one of 13.7 km
21st century, one of 27.55 km, one of 12.8 km
From List of near-parabolic comets
Many are listed, but not many with size estimates, in the 1970, there is one with 5-10 km
1990s Hale-Bob 30 km, C/1999 F2 Dalcanton 18.18 km
2000 12.36 km
2002 Several large comets, 11 km, 58.9 km 30.7 km, 40.7 km, 12.3 km - or was it just that someone cared to calculate?
2004 C/2004 X2 LINEAR 10.5
2005 C/2005 G1 LINEAR 18.9 km
2006 C/2006 M1 LINEAR 16.3 km
C/2006 W3 Christensen 13 km
C/2014 UN271 Bernardinelli–Bernstein was 68.5 km
C/2014 N3 NEOWISE 15 km

Since 2014 there has been few calculation and none exceeds, C/2020 T2 Palomar with its 5.525 km. The reference is:

G. I. Kokhirova; A. M. Buriev; N. T. Sharipova; S. N. Safarov (11–15 March 2024). Long-Period Comet C/2020 T2 (Palomar) and Its Characteristics Based on Observations at the Hissar Astronomical Observatory (PDF). 55th Lunar and Planetary Science Conference. Vol. 3040. The Woodlands, Texas, USA. Bibcode: 2024LPICo3040.1803K.

Even if 3l/ATLAS should show up as something more substantial, there has been many bigger ones before and there was no issue. The above paper however came out only about three years after its passage of the Sun, so perhaps some calculations of more recent comets will be done.

 

[Persej]

An astrophysics blog from my country did a couple of interviews with Avi Loeb, and I got interested. From what I can see, he is trying to encourage scientists to "think outside the box" and to get people to think about the possibility of coming in contact with alien technology. He is not making any definitive claims, just trying to examine the interstellar object phenomenon with an open mind. I understand he is being shunned by the mainstream scientific community, and I see vast numbers of comments from people mocking his views on every article posted about his hypothesis, which is why it is important for scientists like him to express themselves more publicly. Shouldn't any step in a "less limited" type of thinking be applauded?

There are a few comments like this about him on this forum. Is it because he doesn't include the possibility of interdimensional travel and talks about a "messianic" age through humanity learning about extraterrestrial intelligence, and therefore possibly has an "agenda"?

Nothing good will come out of Avi Loeb's sensationalist proclamations. He is just fueling yellow journalism. Here are some comments about him that explain what's wrong with his approach:

Yes, but this is the same problem we have with crackpots. 1) He is not an expert in this field, so he doesn't know what he is talking about. He is primarily a decorated cosmologist, not a space scientist or even any kind of observer. 2) He often insists that his (outside the field, pie in the sky, non-expert) opinions should carry the same weight or more than those of scientists who are experts. 3) When people who are experts in this field point out the issues with his theories, he gets angry and claims he is being silenced. This is not the case. He is not being silenced, this is just how science is done.

Space science and cosmology are extremely different disciplines. It's hard to even explain how different. Being an expert in one doesn't give you a right to barge into the other discipline, tell them a bunch of nonsense, and then insist they are "silencing" you by giving you reasonable and scientific reasons why your theories cannot work.

To be clear: it would be OK for him to be doing this if he was seeking out and working with people who actually know, in detail, what they are talking about when it comes to space science, asteroids, NEOs etc. He isn't doing that though, he is coming up with "out there" theories for attention, which do not have good enough science to back them up, and then crying foul when people tell him that his theories are based on nonsense.

I am a theorist in the same field/an adjacent to the one Loeb used to be in. It is quite common for theorists, in their later years of activity, to start coming up with theories based on relatively wild speculation, for which we have no evidence base, but which we could maybe confirm or deny in 10-15 years. Some of them do this and get lucky, and then they get to have an astronomical object's existence theoretically accredited to them forever. What is much more unusual is to see them do this for fields outside their own, because they think they are somehow so smart, they can go in and "fix" it, despite having no idea what they are doing. This is more-or-less the same as garden-variety quackpottery.

(...)

Loeb doesn't know what he's talking about when it comes to space science, so he can't think of the natural explanations for these phenomena, so he jumps to aliens.

(...)

And then he does media interviews and writes popular books that DON'T couch things as thought experiments. He's aiming to have the benefit of making outlandish claims for public attention with enough plausible deniability to avoid professional risk. And then he gets mad when it doesn't work.

https://www.reddit.com/r/Astronomy/comments/1n6j7s5/avi_loeb_and_3iatlas

Do NASA’s 3I/ATLAS photos show evidence of spacecraft targeting meteors in its path?: Harvard scientist

Harvard scientist Avi Loeb speculated that NASA’s recently released photos of 3I/ATLAS could potentially point to its artificial origins — and even wondered if the so-called comet was purposely targeting and sweeping meteorites out of its path. He posited his theory in a viral new blog post on Medium.

“The extended glow is ahead of the object, not trailing it as expected for a cometary tail,” the astrophysicist told The Post. “In the case of a technological object, it could be a beam of particles or light illuminating the path forward to avoid the hazards of micrometeorites.”

Loeb was referring to a photo of said comet that was snapped by Mars Reconnaissance Orbiter’s HiRISE camera and unveiled with others at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, on Wednesday.

Despite the acclaim over the so-called high-resolution pics, the researcher had labeled them “fuzzy” and said he would analyze the data “quantitatively to extract the most important information out of it.”

He wrote that the aforementioned image was odd, as it showed an extension of the object’s “glowing plume” that preceded ATLAS rather than trailing, as is typical of comets.

He said that the phenomenon would be easy to explain if the streak of gas and dust pointed towards the Sun, which he said would be the result of sunlight shining on pockets of ice within the comet.

Were it oriented away, this would be caused by “radiation pressure or the solar wind.”

However, it’s much more difficult to account for a “plume extended perpendicular to the direction of the Sun and ahead of the object,” he said.

That’s when Loeb dropped the bombshell: “Could this be a technological signature of illuminating or clearing the path from any hazardous micrometeorites that may cause damage to a technological object?”

How would ATLAS accomplish this? “It is possible to charge obstacles with a light beam and then deflect them with a magnetic field, for example,” Loeb told The Post. “There might be more advanced technologies to accomplish this task.”

That wasn’t the scientist’s only theory about our visitor from the cosmos.

In another blog post from Thursday, he scrutinized photos by photographers Michael Jäger, Gerald Rhemann and Enrico Prosperi that showed strange sideways lines, which Loeb believed could potentially be artificial as well.

“The image shows two narrow jets directed opposite to each other and oriented vertically from the 3I/ATLAS-Sun axis,” he explained. “Together with the tail and anti-tail along this axis, the sideways lines constitute an X-shaped pattern. They extend out to a distance of about a million kilometers (620,000 miles) from 3I/ATLAS.”

He explained that the simplest explanation was the “lines are the streak of an Earth-based communication satellite which coincidentally intersected 3I/ATLAS.”

However, if not a satellite streak, he believes the lines highlight “the trail of gas or dust associated with the linear path of small mini-objects that departed from 3I/ATLAS.”

Those mini-objects could be shards of ice that typically break off from the comet’s surface — “or small probes that were released from a technological mothership,” Loeb posited.

“The fundamental question to address in the coming weeks is whether these smaller objects are real and not simply an artifact of a satellite streak, and if real — are they natural or technological in origin?” he declared.

In the prior blog on the HiRISE photo, Loeb said that he hopes everything will become clear in the next few weeks when “large ground-based telescopes as well as the Hubble and Webb telescopes will be able to characterize the jets of 3I/ATLAS.”

NASA’s official position, which the agency reiterated during the recent photo unveiling in Maryland, remains that 3I/ATLAS is a comet.

“This object is a comet. It looks and behaves like a comet, and all evidence points to it being a comet,” declared NASA Associate Administrator Amit Kshatriya. “But this one came from outside the solar system, which makes it fascinating, exciting and scientifically very important.”

Do NASA’s 3I/ATLAS photos show evidence of spacecraft targeting meteors in its path?: Harvard scientist

Does 3I/ATLAS have interstellar headlights?

nypost.com

3I/ATLAS' bizarre trajectory suggests it could be sending 'satellites' to spy on Jupiter: Harvard scientist

Harvard scientist Avi Loeb claims that 3I/ATLAS’ bizarre trajectory suggests that it’s sending “satellites” to Jupiter to gather intel for an “extraterrestrial civilization.”

Loeb told The Post that the comet 3I/ATLAS could use its time near Jupiter — which it will reach on March 16, 2026 — to “seed” additional probes onto the gas giant.

In a new blog post on Medium, the astrophysicist speculated Jupiter is of interest to the comet because Jupiter is “bigger” than Earth and other neighboring planets in our solar system, and therefore acts like an intergalactic beacon.

Loeb said that for the comet to do recon on Jupiter, it would have to move into a region where Jupiter’s gravity dominates over the sun’s. That area contains stable spots where objects can hold position with very little fuel, making them prime real estate for advanced satellites.

As the researcher pointed out, 3I/ATLAS appears to be following this exact path.

Loeb found it an “extraordinary coincidence” that during the interstellar entity’s closest approach to Jupiter in March, it will be at a minimum distance of 53.445 million kilometers (over 33.209 million miles) from Jupiter, based on calculations by NASA’s Jet Propulsion Laboratory.

“It comes exactly at the right distance from Jupiter for Jupiter’s gravity to dominate,” Loeb told News Nation. “So, if it wants to release some probes near Jupiter, that’s where it needs to be.”

He also calculated that 3I/ATLAS may have even executed an in-flight maneuver during its monthlong passage near perihelion — the object’s closest approach to the sun — to ensure it was within proper range.

“The non-gravitational acceleration introduced a small course correction of exactly the magnitude needed,” he declared.

Loeb added that if 3I/ATLAS were indeed alien technology, “it might have fine-tuned its trajectory with the help of [artificial] thrusters” — alluding to the comet’s so-called “jet structure.”

Unfortunately, it’s arrived at perihelion behind the sun, making it invisible to Earthly observatories and thereby preventing us from seeing whether the comet executed such a maneuver, or if it released probes at that time.

Loeb said he hoped that “objects orbiting Jupiter after the passage of 3I/ATLAS could be identified by the Juno spacecraft or by other human-made orbiters around Jupiter.”

This would have major implications for finding out the cosmic interloper’s intentions, per Loeb. “If we find technological satellites of Jupiter that we did not send, it would imply that Jupiter is of interest to an extraterrestrial civilization,” Loeb wrote.

The scientist wrote that “not finding similar gadgets near Earth” could also deliver a major blow to our “ego” as it would indicate we are not only not the center of our solar system, but aren’t even the center of our “cosmic neighborhood.”

As for why 3I/ATLAS would prefer the volatile gas giant to the inhabited Earth, Loeb wrote that this was potentially “because the human species arrived late to the party — only a few million years ago.”

On the contrary, Jupiter — the biggest planet in the solar system — “was visible to the senders of 3I/ATLAS when the mission was launched billions of years ago,” the scientist speculated.

However, the likelihood of 3I/ATLAS embarking on a Jupiter recon mission is relatively low — at least compared to other possibilities, per Loeb.

In fact, the researcher ranked it the least likely in a list of six major 3I/ATLAS anomalies with “no explanation” that he posted on his blog on Sunday.

One more likely probability, per the essay, is that the comet’s anti-tail — where its tail points toward the sun rather than away, as is typical of comets — means it’s emitting a beam of light used to sweep tiny meteors out of the spacecraft’s path.

Most concerning was the comet’s orientation toward the planets in our solar system — which Loeb suggests could’ve been by design.

NASA’s official position, which the agency reiterated during its anticipated photo release in Maryland last week, remains that 3I/ATLAS is a comet.

3I/ATLAS’ bizarre trajectory suggests it could be sending ‘satellites’ to spy on Jupiter: Harvard scientist

“If we find technological satellites of Jupiter that we did not send, it would imply that Jupiter is of interest to an extraterrestrial civilization.”

nypost.com