Quote:The “Wow! Signal” originated from the sky coordinates of Right Ascension (RA)=19h25m=291 degrees and Declination (Dec)=-27 degrees.

On August 12, 1977, the interstellar object 3I/ATLAS was at a distance of about 600 times the Earth-Sun separation (AU) — corresponding to a light-travel time of about 3 days. It had the sky coordinates of RA=19h40m=295 degrees and Dec=-19 degrees. These parameters can be inferred accurately given the lack of non-gravitational acceleration for 3I/ATLAS, as inferred in my latest paper (accessible here).

Hence, the “Wow! Signal” was separated by approximately 4 degrees in RA and 8 degrees in Dec from the direction of 3I/ATLAS. The chance of two random directions in the sky being aligned to that level is about 0.6 percent. If the “Wow! Signal” originated from 3I/ATLAS, how powerful was the transmitter?
The detected intensity of the “Wow! Signal” was in the range of 54–212 Jansky with a bandwidth of about 10 kilohertz. At the distance of 600 AU, this corresponds to a source power of 0.5–2 gigawatts, the output of a typical nuclear reactor on Earth.

The “Wow! Signal” was observed at a frequency of 1420.4556±0.005 megahertz, blue-shifted by about 10 kilometers per second towards Earth relative to the central frequency of the hydrogen line. This blueshift is of the same order of magnitude but smaller than expected from the approach velocity of 3I/ATLAS towards the Sun, 60 kilometers per second.

https://avi-loeb.medium.com/was-the-wow-signal-emitted-from-3i-atlas-d18d4f0d1f1e

Quote:We are fortunate to benefit from the passage of an unusually massive and bright interstellar object (at least a thousand times more massive than the previous two: 1I/`Oumuamua and 2I/Borisov) in the inner solar system through an orbit that is aligned with the ecliptic plane of the planets around the Sun (with a random likelihood of order 0.2%) and that is timed for a close passage near Mars, Venus and Jupiter (with a likelihood of 0.005%). Whether these extremely rare coincidences are a matter of random chance or extraterrestrial intelligent planning remains to be seen by the Mars orbiters. Based on the data their images and spectrographs provide, humanity will know whether it should be grateful to mother nature or to the intelligence of a cosmic sibling.
https://avi-loeb.medium.com/a-preliminary-view-3i-atlas-from-mars-3bd3d2c03c95

(10-06-2025, 05:37 PM)gortex Wrote: NASA have released an image of 3I/Atlas as seen by Perseverance rover on Mars , the elongation is the result of stacking multiple Navcam images make the picture.


https://mars.nasa.gov/mars2020/multimedia/raw-images/image-of-the-week/

Still don't look like a Comet , just sayin.

Quote:CaSSIS could not distinguish the nucleus from the coma, because 3I/ATLAS was too far away. Imaging this kilometre-wide nucleus would have been as impossible as seeing a mobile phone on the Moon from Earth. 
But the coma, measuring a few thousand kilometres across, is clearly visible. The coma is created as 3I/ATLAS approaches the Sun. The Sun’s heat and radiation is bringing the comet to life, causing it to release gas and dust, which collects as this halo surrounding the nucleus. 

The full size of the coma could not be measured by CaSSIS because the brightness of the dust decreases quickly with distance from the nucleus. This means that the coma fades into the noise in the image. 
Typically, material from the coma is swept into a long tail, which can grow up to millions of kilometres long as the comet moves closer to the Sun. The tail is much dimmer than the coma. We can’t see the tail in the CaSSIS images, but it may become more visible in future observations as the comet continues to heat up and release more ice. 
https://www.esa.int/Science_Exploration/Space_Science/ESA_s_ExoMars_and_Mars_Express_observe_comet_3I_ATLAS

Quote:An image of the interstellar object 3I/ATLAS from the Two-meter Twin Telescope in the Canary Islands, Spain. The image, composed of 159 exposures of 50 seconds each, was taken on August 2, 2025.

It shows a faint jet pointed towards the Sun (marked by a purple line), extending out to a projected distance of about 6,000 kilometers from the nucleus (indicated by the crossing point of the thin red lines). The direction away from the Sun (where a generic cometary tail should have pointed), is shown in yellow. (Credit: M. Serra-Ricart et al., October 15, 2025)

Quote:As soon as the Hubble image was publicized, comet experts cheered that 3I/ATLAS behaves as a comet. But their enthusiasm neglected the fact that the image revealed an anti-tail pointing towards the Sun. Realizing this is as shocking as photographing an animal in your backyard which your family members identify as a common street cat, while the image shows a tail coming out of the animal’s forehead. The only attempt to explain this unique quality of 3I/ATLAS was made in the paper I wrote with Eric Keto (accessible here).
https://avi-loeb.medium.com/a-sunward-jet-from-3i-atlas-imaged-by-the-two-meter-twin-telescope-d37ba1808ed2

Quote:On the same day, the brilliant congresswoman Anna Paulina Luna submitted an official letter to Duffy (available here), requesting disclosure of the highest resolution images of 3I/ATLAS, taken by NASA’s HiRISE camera onboard the Mars Reconnaissance Orbiter a month ago on October 2–3, 2025.
https://avi-loeb.medium.com/kim-kardashian-is-welcome-to-join-my-research-team-on-3i-atlas-975ea3356581

(11-04-2025, 01:13 AM)Ninurta Wrote: Something I've been thinking about.

Our annual meteorite showers are caused by the Earth passing through the dbris fields that comets leave in their wake as they pursue their orbits.

If, as they say, this object is an interstellar comet, and if, as they say, it is passing in the plane of the ecliptic, then at some point the earth will pass through it's debris field, giving birth to yet another meteor shower.

Some of those meteors will inevitably become meteorites by landing on the earth's surface.

At some point, one or more of those meteorites will be recovered...

... and we will have our first documented samples of material created outside of our solar system.

I've yet to hear anyone else mention that intriguing possibility.

.

Quote:Recent observations of the interstellar object 3I/ATLAS show that it has developed a faint blueish hue, hinting at a potential colour change. This is the third time experts have seen the comet's colouring shift since it was discovered.
https://www.livescience.com/space/comets/interstellar-visitor-3i-atlas-may-have-just-changed-color-for-the-third-time

Quote:Comets are large objects made of dust and ice that orbit the Sun. Best known for their long, streaming tails
https://spaceplace.nasa.gov/comets/en/

Quote:Based on momentum conservation (as discussed here), I derived here that the mass fraction lost during the perihelion passage of 3I/ATLAS is larger than 13%. For a typical comet, this should have resulted in a massive coma with dust and gas that would have been pushed by the solar radiation pressure and the solar wind to the shape of a typical cometary tail pointing away from the Sun. No such tail is visible in the new images from November 5, 2025.
https://avi-loeb.medium.com/no-clear-cometary-tail-in-post-perihelion-images-of-3i-atlas-e3904b352a7a