(11-07-2025, 06:32 PM)gortex Wrote: The Chinese space agency not only beat NASA to the punch following 3I/Atlas's visit to Mars they also made a gif.


"Space , the final frontier ......"
https://www.space.com/astronomy/comets/chinas-tianwen-1-mars-probe-captures-images-of-interstellar-comet-3i-atlas

Quote:This morning, at 4.10 Universal Time (UT) on November 8, 2025, the interstellar object 3I/ATLAS showed a complex jet structure. M. Jäger, G. Rhemann and E. Prosperi observed 3I/ATLAS at 29 degrees separation from the Sun in the sky, as reported here.

The stacked images, constituting 24 exposures in the green filter— each lasting 35 seconds , 2 exposures in a red filter and 2 exposures in a blue filter, show a large glowing halo extending out to half a million kilometers (5 arcminutes). The images show at least 7 distinct jets, some of which are anti-tails in the sunward direction.

At the time of observations, 3I/ATLAS was 7–10 degrees above the horizon. Eventually, twilight interfered with the observations, which took place under a bright moonlight.
Is the network of jets associated with pockets of ice on the surface of a natural cometary nucleus or are they coming from a set of jet thrusters used for navigation of a spacecraft? We do not know.
For now, let us enjoy the view. After all, a picture is worth a thousand words.

https://avi-loeb.medium.com/a-complex-jet-structure-emanates-from-3i-atlas-after-perihelion-1cc7f8ec7b81

Quote:I calculated here that their mass density is a few million proton masses per cubic centimeter at a distance of a million kilometers from 3I/ATLAS. The product of this mass density and the outflow speed, implies a mass flux of 5 billion tons per month per area of a million-kilometer on a side. I calculated here that the total mass associated with 3I/ATLAS is at least 33 billion tons based on its early dynamics. Adopting an outer surface area for the jetted material of order a million-kilometer squared, I find that 3I/ATLAS may have lost ~16% of its mass. This is consistent with the mass fraction required by its non-gravitational acceleration at perihelion, as I calculated here.

Quote:“Houston, we have a problem” with the natural comet hypothesis! The required surface area of 3I/ATLAS to provide the inferred mass loss from the latest post-perihelion image, is at least 16 times larger than the upper limit derived here from its Hubble image on July 21, 2025.

Was the dramatic mass loss and brightening of 3I/ATLAS at perihelion evidence that it disintegrated? Breakup into fragments would have increased the surface area of its material. Since the surface-to-mass ratio scales inversely with the characteristic radius of fragments, an increase in surface area by a minimum factor of 16 requires that 3I/ATLAS broke into at least 16 equal pieces, and likely many more. This would mean that 3I/ATLAS exploded at perihelion and we are witnessing the resulting fireworks. In other words, the latest image implies that 3I/ATLAS was decimated by heating from the Sun if it is a natural comet.

Quote:The tidal force of the Sun is expected to separate the fragments in the coming weeks, creating an appearance similar to that of the comet Shoemaker-Levi 9 in 1994 near Jupiter. I discussed this possible outcome a month ago here.

However, if upcoming observations would reveal that 3I/ATLAS was not decimated by the Sun and maintained its integrity as a single body, then we will have to consider that it is something other than a natural comet. On December 19, 2025, 3I/ATLAS will get closest to Earth, allowing ground-based telescopes as well as the Hubble and Webb space telescope to diagnose its integrity.

Quote:Technological thrusters require a much smaller mass loss in order to produce the observed jets around 3I/ATLAS. Chemical rockets are propelled by an exhaust speed of 3–5 kilometers per second, which is ten times larger than the maximum ejection speed of volatiles sublimated by sunlight from natural cometary surfaces. Ion thrusters reach an even higher ejection speed of 10–50 kilometers per second. Alien-tech thrusters might employ yet higher exhaust speeds, reducing the required mass loss by several orders of magnitude and making the required fuel a small of the spacecraft mass. Upcoming spectroscopic observations will determine the velocity, mass flux and composition of the jets of 3I/ATLAS. 
Stay curious!

https://avi-loeb.medium.com/did-3i-atlas-just-break-up-near-the-sun-c27f7479f3e0

(11-11-2025, 05:16 PM)gortex Wrote: Looks like a deal has been agreed to end the government shutdown so hopefully NASA will release the long awaited MRO data and images as soon as the ink is dry.

"The main threat to new knowledge is the arrogance of expertise."
Avi Loeb.

Quote:The series of collimated jets in post-perihelion images of 3I/ATLAS extend out to a million kilometers towards the Sun and 3 million kilometers away from the Sun. They could be generated by sunlight heating pockets of ice on the surface of a natural object for about a month or by thrusters on the surface of a spacecraft. In the first case, the jet speed should be at most a few hundred meters per second whereas in the second case, it should be at least a few kilometers per second. Spectroscopic measurements of molecular or atomic lines can easily distinguish between these scenarios by measuring the Doppler velocity of these jets in the coming weeks. Science is fun because it allows us to choose the correct interpretation based on the humility to learn from evidence rather than from the arrogance of expertise.

My assessment is that NASA did not release as of yet the HiRISE images of 3I/ATLAS when it arrives within 29 million kilometers from Mars on October 3, 2025, because of bureaucratic reasons during the U.S. Government shutdown over the past 42 days. It is interesting to note that the HiRISE website here releases many new images of Mars on a daily basis but singles out 3I/ATLAS by stating: “Any images of the interstellar comet 3I/ATLAS are considered NASA-wide news. Because the federal government is in shutdown, communications of NASA news have been suspended.” An interesting question is why was 3I/ATLAS singled out. It should have been straightforward to share data through a suitable repository with the scientific community. Science should not be held hostage by bureaucracy.

https://avi-loeb.medium.com/q-a-about-3i-atlas-and-beyond-5810fe3cefa8

(11-12-2025, 05:05 PM)gortex Wrote: Observation on the jets coming from 3I/Atlas post perihelium and silence over the long awaited MRO images.

Quote:The series of collimated jets in post-perihelion images of 3I/ATLAS extend out to a million kilometers towards the Sun and 3 million kilometers away from the Sun. They could be generated by sunlight heating pockets of ice on the surface of a natural object for about a month or by thrusters on the surface of a spacecraft. In the first case, the jet speed should be at most a few hundred meters per second whereas in the second case, it should be at least a few kilometers per second. Spectroscopic measurements of molecular or atomic lines can easily distinguish between these scenarios by measuring the Doppler velocity of these jets in the coming weeks. Science is fun because it allows us to choose the correct interpretation based on the humility to learn from evidence rather than from the arrogance of expertise.

My assessment is that NASA did not release as of yet the HiRISE images of 3I/ATLAS when it arrives within 29 million kilometers from Mars on October 3, 2025, because of bureaucratic reasons during the U.S. Government shutdown over the past 42 days. It is interesting to note that the HiRISE website here releases many new images of Mars on a daily basis but singles out 3I/ATLAS by stating: “Any images of the interstellar comet 3I/ATLAS are considered NASA-wide news. Because the federal government is in shutdown, communications of NASA news have been suspended.” An interesting question is why was 3I/ATLAS singled out. It should have been straightforward to share data through a suitable repository with the scientific community. Science should not be held hostage by bureaucracy.

https://avi-loeb.medium.com/q-a-about-3i-atlas-and-beyond-5810fe3cefa8

Image of Atlas as seen yesterday courtesy of the Virtual Telescope Project.

I wonder if Atlas has broken up perhaps it separated its constituent parts ready for the next stage , the lack of communication from NASA  is because of the government shutdown they can't hold a press conference and they need a press conference for ..... Disclosure !!!!!


Probably not but these are strange times.

Quote:Images taken of 3I/ATLAS on November 11, 2025 show a single body, with no evidence for breakup following the perihelion passage two weeks earlier. The images, reported here, were taken by David Jewitt and Jane Luu on the Nordic Optical Telescope with a primary mirror of 2.56-meter diameter, located at La Palma in the Canary Islands

Quote:Given the large-scale jets reported recently, the fact that 3I/ATLAS remains a single body is surprising for a natural comet. In particular, the large-scale image of 3I/ATLAS reported here on November 9, 2029 shows jets reaching out to ~1 million kilometers towards the Sun and ~3 million kilometers in the opposite direction, as discussed here. For a natural comet, the outflow velocity of the jets is expected to be 0.4 kilometers per second, of order the sound speed of gas at the distance of 3I/ATLAS from the Sun. At that speed, the jets must have persisted over a timescale of 1–3 months.

Given that the jets towards the Sun were stopped by the solar wind at a distance of a million kilometers, I calculated here that their mass density is a few million proton masses per cubic centimeter at a distance of a million kilometers from 3I/ATLAS. The product of this mass density and the outflow speed, implies a mass flux of 5 billion tons per month per area of a million-kilometer on a side.

https://miro.medium.com/v2/resize:fit:4800/format:webp/1*wY3tXWhAF2ffXDHuQgmWWQ.png

Quote:Thanks to the good weather, we managed to image comet C/2025 K1 ATLAS again, finding a dramatic situation in the inner coma, after the recent outburst and fragmentation, with several pieces/clouds visible. We also provide an animation showing the evolution in two days.
https://www.virtualtelescope.eu/2025/11/13/comet-c-2025-k1-atlas-fragmentation-13-nov-2025-image-and-animation/

(11-14-2025, 10:20 PM)gortex Wrote: A new image of Atlas seems to suggest the object is now 3 objects.

Quote:Thanks to the good weather, we managed to image comet C/2025 K1 ATLAS again, finding a dramatic situation in the inner coma, after the recent outburst and fragmentation, with several pieces/clouds visible. We also provide an animation showing the evolution in two days.
https://www.virtualtelescope.eu/2025/11/13/comet-c-2025-k1-atlas-fragmentation-13-nov-2025-image-and-animation/

Separation complete , I wonder which one is coming to Earth.

Quote:1. Its retrograde trajectory is aligned to within 5 degrees with the ecliptic plane of the planets around the Sun, with a likelihood of 0.2% (see here).

2. During July and August as well as in early November of 2025, it displayed a sunward jet (anti-tail) that is not an optical illusion from geometric perspective, unlike familiar comets (see here).

3. Its nucleus is about a million times more massive than 1I/`Oumuamua and a thousand times more massive than 2I/Borisov, while moving faster than both, altogether with a likelihood of less than 0.1% (see here and here).

4. Its arrival time was fine-tuned to bring it within tens of millions of kilometers from Mars, Venus and Jupiter and be unobservable from Earth at perihelion, with a likelihood of 0.005% (see here).

5. Its gas plume contains much more nickel than iron (as found in industrially-produced nickel alloys) and a nickel to cyanide ratio that is orders of magnitude larger than that of all known comets, including 2I/Borisov, with a likelihood below 1% (see here).

6. Its gas plume contains only 4% water by mass, a primary constituent of familiar comets (see here).

7. It shows extreme negative polarization, unprecedented for all known comets, including 2I/Borisov, with a likelihood below 1% (see here).

8. It arrived from a direction coincident with the radio “Wow! Signal” to within 9 degrees, with a likelihood of 0.6% (see here).

9. Near perihelion, it brightened faster than any known comet and was bluer than the Sun (see here).

10. It exhibits sunward and anti-solar jets which require an unreasonably large surface area in order to absorb enough sunlight needed to sublimate enough ice to feed the mass flux of these jets (as calculated here).

11. Near perihelion it exhibits non-gravitational acceleration which requires massive evaporation of at least 13% of its mass (as calculated here), whereas preliminary images indicate that the object maintained its integrity and did not break up (as discussed here).

12. Its tightly-collimated jets maintain orientation across a million kilometers in multiple directions relative to the Sun despite its measured rotation.

So far, I have not updated my rank for 3I/ATLAS on the Loeb Scale (defined here and quantified here), since we expect a flood of new data in the coming weeks. If the measured speed, composition and mass flux of the jets are consistent with sublimation of volatiles from pockets of ice on the surface of a natural comet, I will reduce my Loeb Scale rank. On the other hand, if the speed and mass flux will be inconsistent with warming by sunlight of a natural comet, then I will raise the Loeb Scale rank to a higher value than 4. The rank will reach a value of 10 if there is evidence for new objects near Earth or Mars that are related to 3I/ATLAS

https://avi-loeb.medium.com/the-12th-anomaly-of-3i-atlas-orientation-of-the-jets-is-not-smeared-by-rotation-30035318a5fd

Quote:Corresponding Address:
Omer Eldadi
B.Ivcher School of Psychology
Reichman University
The University 8, Herzliya, Israel
Email: Omereldadi@gmail.com