Three observations emerge from the latest forensic analysis that demand immediate scientific attention:
- The object displays extraordinary brightness for its distance and size, suggesting either unusual surface properties or unexpectedly efficient energy conversion.
- Multiple jet structures emanate in various directions, including toward the Sun, while the expected dust tail remains conspicuously dim or absent.
- The structural coherence and directional precision of these features challenge standard models of cometary behavior.
New telescope data reveals bright nucleus with multiple directional jets but mysteriously absent traditional tail
USA HERALD – A new image captured on November 17, 2025, at 17:04 UTC by French astronomer François Kugel has provided the most detailed post-perihelion view yet of interstellar object 3I/ATLAS — and what it reveals is forcing astronomers to confront a series of characteristics that refuse to conform to our understanding of how natural comets behave.
Using a 0.4-meter aperture telescope, Kugel combined 22 exposures of 30 seconds each to create a composite image that captures the comet at magnitude 11.8, traveling at 1.84 arc minutes per hour across the constellation. The observation took place with the object positioned at right ascension 12h 44m 52.86s and declination +03° 18′ 14.2″, with the Sun’s direction pointing toward the lower left corner of the frame.
What emerges from this image is a portrait of an object that seems to be writing its own rules.
The Brightness Paradox
The first anomaly that strikes any observer examining this image is the intense, almost stellar brightness of 3I/ATLAS’s nucleus. The November 17 image displays the same multi-directional jet features observed the previous day, suggesting stable structural patterns rather than chaotic outgassing.
At its current distance from both the Sun (approximately 1.43 astronomical units) and Earth (2.16 AU), this level of brightness requires explanation. The nucleus appears as a concentrated point of light surrounded by a diffuse coma, but the intensity suggests either an unusually reflective surface, exceptionally efficient sublimation of volatiles, or surface properties that don’t match our models of ancient icy bodies.
Think of it this way: imagine a campfire that somehow appears just as bright whether you’re standing ten feet away or fifty feet away. The physics doesn’t add up unless something about the fire itself has changed, or unless it’s not really a fire at all.
Jets Without a Conventional Tail
The most striking feature in the November 17 image is what’s simultaneously present and absent. Multiple narrow jets are visible, directed both toward and away from the Sun, with clear structure despite the object’s decreasing brightness.
These jets display remarkable characteristics. Rather than the broad, diffuse plumes typically associated with cometary outgassing, they appear as discrete, collimated streams — almost engineered in their precision. Images from November 8 showed a complex jet structure of at least seven jets, some of which are anti-tails, and this pattern has persisted through subsequent observations.
What’s conspicuously missing is the traditional cometary tail — that sweeping arc of dust and gas blown away from the nucleus by solar radiation pressure. While the tail of the comet was observed by Michael Jäger on November 8, 2025, in many images around this period, including the November 17 observation, the tail appears remarkably faint or difficult to detect compared to the brightness of the nucleus and the prominence of the jet structures.
For comparison, an image of the solar system’s comet Lemmon, taken on November 3, 2025, shows a clear cometary tail pointing away from the Sun. The contrast is stark.
The Anti-Tail Phenomenon
One of the most perplexing features visible in the November 17 image is the presence of what appears to be an anti-tail — a jet-like structure pointing toward the Sun rather than away from it. During July and August 2025, 3I/ATLAS displayed a sunward jet that points forward along its direction of motion rather than away from the Sun as normal comets do.
Anti-tails are not unknown in cometary science. They can occur when Earth crosses through a comet’s orbital plane and dust sheets create an optical illusion of a sunward-pointing tail. However, multiple analyses have confirmed that 3I/ATLAS displayed a sunward jet that is not an optical illusion from geometric perspective, unlike familiar comets.
The sunward jets observed in 3I/ATLAS have proven persistent across multiple observations and viewing geometries, suggesting this is a real physical phenomenon rather than a trick of perspective.
The image shows two anti-tail jets out to 10 arcminutes towards the Sun accompanied by a longer collimated jet extending away from the Sun out to 30 arcminutes, corresponding to spatial scales of nearly one million kilometers for the sunward jets and almost three million kilometers for the tail jet.
The Mass Loss Puzzle
Here’s where the physics becomes particularly challenging. Given that the jets towards the Sun were stopped by the solar wind at a distance of a million kilometers, calculations show their mass density is a few million proton masses per cubic centimeter at a distance of a million kilometers from 3I/ATLAS.
This leads to an extraordinary conclusion: The mass loss rate is estimated at 50 billion tons per month, comparable to the minimum mass associated with 3I/ATLAS of 33 billion tons.
Let that sink in. The object appears to be ejecting mass at a rate that would equal its entire estimated minimum mass over the course of the perihelion passage. For a natural comet, this would suggest near-total disintegration. Yet images taken of 3I/ATLAS on November 11, 2025 show a single body, with no evidence for breakup following the perihelion passage.
To maintain this level of mass ejection, 3I/ATLAS must have received at least 3×10¹⁸ Joules, requiring an absorbing area larger than 1,600 square kilometers — the area of a sphere with a diameter of 23 kilometers, 4 times larger than the maximum diameter of 5.6 kilometers inferred from Hubble Space Telescope imaging data.
In simpler terms: the comet appears to be releasing more energy than it should be able to capture from sunlight alone, given its estimated size.
Structural Coherence Under Extreme Conditions
The similarity between composites from November 16 and 17 indicates stable jet morphology over a period of at least 24 hours. For a small, active interstellar object experiencing the intense thermal stresses of a solar encounter, this level of structural consistency is notable.
Most comets display rapid changes in their jet structures as different regions of the nucleus heat up and cool down with rotation. The fact that 3I/ATLAS maintains consistent jet patterns suggests either unusually slow rotation, an extremely stable internal structure, or selective activation of specific surface regions.
Harvard University’s Professor Avi Loeb noted that given the large number of jets appearing in many directions, the reported non-gravitational acceleration requires much more than 10-20% of its initial mass to have been ejected near perihelion.
What Natural Explanations Remain?
The scientific community has proposed several natural mechanisms that could explain some of these observations. Viewing geometry plays a crucial role — when Earth passes through a comet’s orbital plane, dust sheets can create apparent anti-tails. Gas emissions can dominate appearance around perihelion, potentially making dust tails less visible.
The chemical composition of 3I/ATLAS also suggests it may be fundamentally different from solar system comets. The comet has been releasing more carbon dioxide than water, and more nickel than iron, compared with comets from our solar system — a signature that could explain unusual sublimation patterns.
Some researchers argue that the comet’s apparent lack of tail isn’t anything to get excited about, noting that if you examine the November images closely, you can see it’s a bit brighter on the left side of the comet, suggesting we’re seeing the tail basically head-on, right behind the comet.
Yet each natural explanation addresses individual anomalies while struggling to account for the complete picture. The combination of unusual brightness, persistent multi-directional jets, weak or absent dust tail despite significant mass loss, and structural coherence under thermal stress creates a pattern that challenges our standard cometary models.
The Level 5 Question
According to the Loeb Scale classification system, 3I/ATLAS currently sits at Level 4 — “Anomaly Meeting Potential Technosignature Criteria.” The November 17 image reinforces many of the characteristics that placed it at this level: unusual jet structure, anomalous brightness patterns, and behavior that deviates from standard cometary physics.
To reach Level 5 — “Suspected Passive Technology” — the object would need to display unusual speed, surface composition inconsistent with cosmic-ray bombardment for its implied age or velocity, or most critically, absence of cometary activity despite substantial non-gravitational acceleration.
The irony is that 3I/ATLAS shows too much visible activity to easily qualify for Level 5 under the “absence of cometary activity” criterion. Yet the nature of that activity — its geometric precision, its energetic excess, its structural stability — doesn’t quite match natural cometary outgassing either.
We’re left in a classification gray zone where the object displays characteristics that don’t cleanly fit either natural or technological categories as we’ve defined them.
The 27-Day Window
With 3I/ATLAS scheduled to make its closest approach to Earth on December 19, 2025 — in just 27 days— astronomers have a rapidly closing window to gather additional data. Every new image, every spectrum, every measurement adds pieces to a puzzle that becomes more complex with each observation.
The November 17 image by François Kugel represents a snapshot of an object that continues to challenge our understanding. Its bright nucleus, multiple directional jets, and mysteriously subdued traditional tail create a portrait that doesn’t quite match anything we’ve seen before.
Whether 3I/ATLAS proves to be an ancient comet with exotic chemical composition and unusual internal structure, or something that forces us to expand our categories of what can travel between the stars, the evidence captured in images like this November 17 observation will be studied for years to come.
