The MeerKAT radio telescope in South Africa has started to receive radio signals from the mysterious 3I/Atlas interstellar object racing through our solar system, adding to the interest in it and fueling more speculation on  whether this is an ordinary comet or an alien spacecraft. In recent days, a series of images snapped by various space observing equipment has made many wonder about what this object is.

The MeerKAT radio telescope is  array of 64 interlinked dishes, sitting about 55 miles  from the small Northern Cape town of Carnarvon in the Karoo; it is integrated into the Square Kilometre Array and is managed by the SKA Observatory group.Designed entirely by South Africans, MeerKAT is currently recognized as the most advanced radio telescope on Earth, and is among several pathfinder facilities proving the science and technology that is used by scientists around the world.

The radio signal from 3I/ATLAS (detected by MeerKAT telescope is absorption lines from hydroxyl (OH) molecules at 1665-1667 MHz. This was radio frequency absorption meaning the object is actively interacting with solar radiation at a molecular level.

But scientists are quick to point out this is likely not an alien broadcasting a signal; instead, it is the chemical process involved when a comet outgasses water.

One scientist, an outspoken astrophysicist at Harvard University, Avi Loeb confirmed this radio signal likely reflects the usual outgassing of water of an ordinary comet3I. However, in recent days and weeks, Loeb has been extremely vocal in hypothesizing that other phenomena involved with this object may be more indicative of an alien spacecraft than a ordinary comet moving through our solar system.

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.

A stunning new photo just snapped of 3I/Atlas last weekend shows something shocking: a huge plume of some kind of material on one side, along with emissions  off the opposite side.   Avi Loeb  believes these images of the  mysterious interstellar object named 3I/ATLAS could be additional evidence of  a type of jet engine or propulsion system on board an alien spacecraft.   And as new imagery has become available, Loeb continues to express concern that this object, which should near Earth in mid-December, may not be a comet but rather an alien spacecraft instead.

The object was discovered on July 1, 2025 by the NASA-funded ATLAS survey telescope at Río Hurtado, Chile. ATLAS stands for the Asteroid Terrestrial-impact Last Alert System which is designed to alert officials of potential asteroids heading to Earth. This newly discovered object was entering the inner Solar System at a speed of 140,000 mph relative to the Sun and was located 325 million miles from Earth. It was initially moving in the sky along the border of the constellations Serpens Cauda and Sagittarius, near the galactic plane. These initial observations initially suggested that the object could be on a highly eccentric path that might come close to Earth’s orbit, which led the International Astronomical Union Minor Planet Center to list the object on the Near-Earth Object Confirmation Page until the orbit could be confirmed. Because it is the third confirmed interstellar object passing through the Solar System, it was given the prefix “3 I” after 2I, known as Borisov, and 1I known as ‘Oumaumua.

In his blog on Medium, with new imagery in hand, Loeb writes, “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 an angular separation of 30 arcminutes, roughly the diameter of the Sun or the Moon. At the current distance of 3I/ATLAS from Earth, 326 million kilometers, these angular extents correspond to spatial sizes of 0.95 million kilometers for the sunward anti-tail jets and 2.85 million kilometers for the tail jet away from the Sun. This enormous spatial scale is three orders of magnitude larger than the scale of the glowing halo around 3I/ATLAS in the Hubble Space Telescope image from July 21, 2025.”

Loeb sets the stage for why it makes sense to consider this is something other than a usual, natural comet: “For a natural comet, the outflow velocity of the jets is expected to be merely 0.4 kilometers per second, of order the sound speed of gas at the distance of 3I/ATLAS from the Sun. In order for the jets to extend over the observed scales, they should have been ejected for timescales of 3 months for the tail and 1 month for the anti-tail.”

Loeb adds his thoughts on alien propulsion, describing the math used to determine whether this is a typical comet or something else. He writes, “If, however, we consider the possibility that the jets emanating from 3I/ATLAS are associated with technological thrusters, then the required mass loss can be 1–2 orders of magnitude smaller with human-made technologies. 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 cometary surfaces. Ion thrusters reach an even higher ejection speed of 10–50 kilometers per second. Furthermore, alien technology might employ thruster with yet higher speeds, reducing the required mass loss by more than 2 orders of magnitude and making the required fuel less than a percent of the mass of the spacecraft.”

Loeb concludes his latest blog post with a question: “Given these considerations, is 3I/ATLAS of natural or technological origin? Upcoming spectroscopic observations will allow us to determine the velocity, mass flux and composition of its jets and hence answer this foundational question. The foundation of pioneering scientific research is the humility to learn rather than the arrogance of expertise.”

In recent days as imagery has become available, Loeb has gone through great lengths to share his thoughts on the mysterious interstellar object. Since it was discovered earlier this year, he’s questioned whether it is a comet or something else since.

Additional analysis shows that the object follows an unbound, hyperbolic trajectory past the Sun. If it’s a comet, it should not come closer than about twice the distance of the Sun to Earth, so it wouldn’t pose a collision threat. If its path doesn’t change significantly, it probably won’t be bright enough to become visible in binoculars or to the naked eye. But during the solar conjunction on October 21, the comet could be observed by the GOES-19 weather satellite.

However, the object is not behaving like a typical comet. The object had an unexplained increase in speed after passing close to the Sun. And unlike normal comets, 3I/ATLAS shows no visible gas or dust emissions that could explain its acceleration. New imagery also shows the lack of a tail which a comet would have as it travels around the Sun. To add to the confusion, some imagery has also suggested the object is changing colors while other imagery shows it changing shape.

The object also appears to be exhausting a significant amount of CO₂ or Carbon Dioxide. Carbon dioxide   is a colorless, odorless gas that is a typically a natural component of the air and part of the global carbon cycle. It plays an important role in photosynthesis, in which plants convert  the gas into oxygen. A significant amount of carbon dioxide is created by  human activities such as the burning of fossil fuels, such as through a jet aircraft or automobile.

But within the core 3I/ATLAS, the mixing ratio of carbon dioxide to water is extremely high, making it one of the most abundant volumes of carbon dioxide to be seen from a comet. The reason for the high abundance of this greenhouse gas in  3I/ATLAS’s core is uncertain. Some scientists believe  this could either mean that it’s a  comet has a carbon dioxide-rich  nucleus or there is some mechanism limiting the sublimation of water from its nucleus. But some also believe this could be the exhaust of an extraterrestrial spacecraft.

Harvard Professor Avi Loeb is one scientists that believes 3I/Atlas is a spaceship. And he believes it’s been releasing mini-spaceships. On his blog, the scientist writes he believes nine key points in his hypothesis show that this is an alien mother ship which could be releasing “mini-drones” as it passes behind the Sun. He doesn’t completely rule out that 3I/Atlas is a comet, but he’s fairly convinced this is alien spacecraft.

The first of nine points is that the trajectory of this object falls within just 5 degrees of the Earth’s path around the sun. Loeb says there’s a 0.2% chance of such an orbit from happening naturally from an interstellar space object. His second point was the object also passed Mars and Jupiter and the timing of the journey to get a close-up view of the planets is statistically remote too.

The third point Loeb raises is the tail or “anti-tail” of this object if it is a comet. Some astronomers have observed 3I/Atlas “growing” a second tail, which points in the direction of the sun. Loeb wrote, “This anomalous anti-tail, not a result of geometric perspective, had never been reported before for solar system comets,”

The fourth point deals with this size. Loeb believes if it is a comet, it is larger than 3 miles representing a mass of more than 33 billion tons. Loeb said this would make this object an unrealistic 3-5x larger object than the previous two interstellar objects found in our solar system.

The fifth point deals with the nickel-to-iron ratio found in this object’s gas plume. Like the unusually rich carbon dioxide gas, which is Loeb’s sixth point,  there is an “extreme abundance” of nickel and iron in its gas plume. This is not expected in comets and Loeb believes this indicates the presence of “industrially-produced nickel alloys” built by aliens.

For the 7th point, Loeb says the object is extremely negatively polarized.  “The combination of low inversion angle and extreme negative polarization is unprecedented among comets and asteroids, marking 3I/ATLAS the first object known with such polarimetric behavior and representing a previously unobserved population,” Loeb wrote in his blog post.

For the 8th point, Loeb believes this object may have emitted a “Wow! Signal” in 1977.  That was a highly unusual narrowband radio signal that was observed by scientists  at Ohio State University’s Big Ear radio telescope.  Many believed that such an unusual signal came from an extraterrestrial entity and Loeb believes this object originated from the area where this signal came from too.

For the 9th point, Loeb believes the unusual color of the object proves it isn’t a comet. For three times since being observed earlier this year, the object has changed color, most recently from red to blue.  The object was also observed to be green at one point.  Scientists do not know with a high degree of confidence why these colors changed.

Days ago, Congresswoman Anna Paulina Luna wrote to Acting NASA Director Sean Duffy to release images of the mystery object. She writes, “This information is of great importance to advancing our understanding of interstellar visitors and their interactions with our solar system.”  NASA has been under scrutiny following allegations that it withheld high-resolution images of the interstellar object , prompting speculation about what the agency knows and why it has stayed silent.

Avi Loeb accused NASA of “burying the evidence” related to 3I/ATLAS, claiming  that NASA’s HiRISE camera aboard the Mars Reconnaissance Orbiter captured a detailed image of the comet on October 2, but the image hasn’t been released to the public. NASA has not yet publicly offered any comment or  addressed any  specific allegations about unreleased imagery of 3I/ATLAS.

 

There is more pressure for the science community to share images and insights around the mysterious 3I/Atlas object, including from Congress: https://t.co/pP5GDLYUGD

— the Weatherboy (@theWeatherboy) November 6, 2025

It could be possible that the ongoing government shutdown is hampering NASA’s ability to reply to these concerns.

While NASA has been quiet, China spoke up about the object this week, releasing photographs snapped in space in the process. The China National Space Administration (CNSA) released an image snapped by Tiawen-1, showing the comet’s bright nucleus surrounded by a vast coma stretching between 3,100 and 6,200 miles across. The photos were taken with the orbiter’s High-Resolution Imaging Camera (HiRIC), which has been orbiting Mars since February 2021.

“This is the first attempt to photograph such a distant and relatively faint target (10,000 to 100,000 times darker than a target on the surface of Mars),” the CNSA said in a statement. “Through the collaborative research of the Tianwen-1 team, combined with the orbital characteristics, brightness characteristics, geometric dimensions, and scientific payload technical capabilities of the orbiter, the feasibility assessment of the observation mission.”

 

SpaceX founder Elon Musk discussed the mysterious object on a recent Joe Rogan podcast. Elon Musk said 3I/ATLAS could be “aliens,” since something beyond gravity is impacting its trajectory.

With new images released today, Loeb believes they show the presence of 7 unique jets on the 3I/Atlas, with some pointed towards the sun as “anti-tails.”

Loeb writes in his blog today, “Given that a large number of jets appear in many directions, the reported non-gravitational acceleration of 3I/ATLAS  requires much more than 10–20% of its initial mass to have been ejected near perihelion. Only a fraction of that mass carries an excess momentum in a preferred direction. This means that the cloud of debris around 3I/ATLAS must represent a substantial fraction of its initial mass for a natural comet. However, technological thrusters could give the object a boost with much less mass jetted out at a higher speed.”

Loeb asks, “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?”. In his blog, Loeb simply answers, “We do not know.”

3I/Atlas is due to get closest to Earth on December 19, 2025.

“My hope is that data collected in the coming weeks, especially around December 19 — when 3I/ATLAS gets closest to Earth, will reveal the true nature of this interstellar object,” wrote Loeb on his blog.