3I/ATLAS: Interstellar Visitor or Alien Probe?

Are We Detecting Alien Life with 3I/ATLAS?

Since mankind realized the immensity of space, the question of the existence of other life forms, possibly intelligent ones, has inflamed our imagination. So far, the search for signs of intelligence beyond Earth has been unsuccessful, from the non-existence of Martian canals to the inconclusive results of the SETI program.

This is not to say that we have zero signs of possible life, with, for example, suspicious dimming of some stars, with already 60 stars that could match the profile of so-called Dyson sphere megastructures.

Similarly, some chemical signatures detected from afar could indicate the presence of microscopic life on Mars and Venus.

Astronomers are now questioning the natural origin of another stellar object, the item called 3I/ATLAS, originating from outside our solar system and bound to pass through the inner solar system by the end of October 2025.

This item displays some rather strange characteristics that are not easily explained, as they differ from every other comet and asteroid observed before. So while this is a rather extraordinary claim, some serious scientists are now at least considering the possibility of an artificial origin.

Detecting Interstellar Objects

Most of the asteroids, comets, and planets of the Universe are bound to the gravity of one or several stars. But sometimes, some are bound to be ejected from their stable orbit and flung into the almost unimaginable space between the stars.

So while they are rare, space objects coming from other solar systems, potentially even older than our Sun, should, from time to time, cross our path.

So far, already 3 interstellar objects have been detected: 1I/Oumuamua in 2017, 2I/Borisov in 2019, and 3I/ATLAS in 2025.

The exact nature of Oumuamua is still hotly debated, with some considering it a comet, some an asteroid, and some even considering an artificial origin. A particularly puzzling observation was that Oumuamua also unexpectedly accelerated due to some force other than gravity.

But as it quickly left the solar system without the possibility of studying it further, it might be impossible to ever know.

Borisov has been confirmed to be a comet, proving that natural objects can indeed come from interstellar space.

3I/ATLAS nature is still unclear, but as it comes closer to us, better observation could clarify its composition and explain some of the observations done so far.

The reason why we are suddenly finding more of these interstellar objects passing by Earth is due to a recent increase in our capacity to detect them. Among these new instruments can be mentioned the Asteroid Terrestrial-impact Last Alert System (ATLAS), an asteroid impact early warning system developed by the University of Hawaii and funded by NASA

3I/ATLAS was found by chance when the Vera C. Rubin Observatory was performing its commissioning tests.

Source: NASA

As we seem to be finding a lot more interstellar objects as soon as we started to look, it seems they are a lot more common than previously thought.

What Makes 3I/ATLAS Strange?

Three scientists at the Initiative for Interstellar Studies (UK) and Harvard University (USA) are discussing in a scientific paper the surprising features of 3I/ATLAS, titled “Is the interstellar object 3I/ATLAS alien technology? ” and published in the International Journal of Aerodynamic Control & Aviation Mechanics¹.

Trajectory

Using OITS (“Optimum Interplanetary Trajectory Software”), they analyze the trajectory and movements of 3I/ATLAS.

They first notice that its trajectory is remarkable in that it is almost perfectly aligned to the ecliptic of the solar system (the “disk” on which almost all planets’ orbit is fitting into) and will pass very close to the solar system planets like Mars, Venus, and Jupiter, a rather unlikely trajectory, measured at less than 0.005% if happening randomly.

Source: International Journal of Aerodynamic Control & Aviation Mechanics

While certainly not conclusive, this trajectory would make perfect sense for an intentional passage close to studying these planets, and being very “lucky” is due to randomness.

However, contrary to Oumuamua, 3I/ATLAS does not seem to display a change of speed unrelated to gravity.

Composition

Only a rather blurry and poor image of 3I/ATLAS has been captured so far, making it unclear what it is made of.

If it is an asteroid (made of metal and rocks), it has to be a big one to justify its luminosity, at least 20km in diameter.

If it is a comet (made mostly of water and dust), it would be surrounded by a halo of water vapor and gas as it gets closer to the Sun and warms up.

Multiple instruments now confirm active outgassing. JWST spectroscopy detected a CO₂-dominated coma with H₂O, CO, OCS, water ice and dust, while ESO’s VLT picked up CN emission and strong Ni I lines (with no Fe I). Hubble imaging also reveals a visible coma. Together, these observations show 3I/ATLAS behaving as an active comet, albeit with unusual chemistry.

If it is a natural asteroid, such a large size is considered very unlikely. So this would leave scientists to conclude it is either a very rare event captured by chance as soon as we started looking, or that our understanding of interstellar objects is very wrong.

Odd Chemistry

The Very Large Telescope (VLT) in Chile detected nickel in 3I/Atlas but not iron.

Meanwhile, the James Webb Space Telescope (JWST) measured a surprisingly high amount of carbon dioxide compared to water vapor.

“We just cracked open the door to a whole new world of chemistry that we never had access to before,”

Thomas Puzia – Astronomer at the Pontifical Catholic University of Chile

One hypothesis for 3I/ATLAS’s unique composition is that it has been soaring through interstellar space for an extraordinarily long time, perhaps seven billion years or more

“If this object has passed through the [galactic] disk a few times, it probably passed through interstellar clouds, probably passed through star-forming regions where there’s new giant stars being born, supernovae going off.

It’s probably passed through a whole range of different environments.”

Martin Cordiner, an astronomer at the Catholic University of America

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Could 3I/ATLAS Serve an Artificial Purpose?

The authors of the paper discuss that the close flyby of 3I/ATLAS to many planets would be ideal for dropping probes flying at a speed of ∼5 km/s, something that even one of our chemical rockets could manage.

Entering a stable orbit around Jupiter through aerocapture and a solar sail could also be possible, using a circular sail or a circular solar sail of ∼ 10 km in radius.

Still, none of these is proof of an artificial origin, something openly recognized by the author of the paper. They want the scientific community to be open to acknowledging the hypothesis, instead of automatically rejecting it out of principle and a rather unscientific dismissal of the possibility.

By far the most likely outcome will be that 3I/ATLAS is a completely natural interstellar object, probably a comet, and the authors await the astronomical data to support this likely origin.

Most scientists might be worried about damaging their reputation and career by even considering the possibility of alien technology. This was notably the case with Oumuamua, despite the very odd and still unexplained acceleration (and very high luminosity), which could be more consistent with an artificial solar sail than a natural asteroid.

In the case of ATLAS, the unusual composition and unlikely trajectory are equally puzzling, but the lack of an unexplained speed change limits the case for an artificial origin.

Limiting data plus reputational risks might explain why only someone with the credentials of Avi Loeb, who chaired Harvard’s Department of Astronomy from 2011 to 2020 and is the Director of the Institute for Theory and Computation at the Center for Astrophysics, could go on to explore publicly this hypothesis about 1I/Oumuamua and 3I/ATLAS.

Upcoming 3I/ATLAS Observations and Data Releases

Thanks to the passage of 3I/ATLAS close to Mars and Jupiter, we might get a better view of the object with man-made probes that are currently studying these planets than with Earth-bound telescopes.

Source: Space.com

Between 1 and 7 October, ESA’s ExoMars Trace Gas Orbiter (TGO) and Mars Express spacecraft turned their eyes towards interstellar comet 3I/ATLAS.

“This was a very challenging observation for the instrument. The comet is around 10,000 to 100,000 times fainter than our usual target.

At this point, it is uncertain whether the coma and tail were bright enough for a spectral characterisation.”

Nick Thomas – Principal Investigator of the CaSSIS camera

The next observation will be done with the Jupiter Icy Moons Explorer (Juice) in November.

Though Juice will be further from 3I/ATLAS than our Mars orbiters were last week, it will see the comet just after its closest approach to the Sun, meaning that it will be in a more active state.

We don’t expect to receive data from Juice’s observations until February 2026

Intercepting 3I/ATLAS?

Sending a probe close enough to the interstellar object would solve any question we have about it.

Unfortunately, it is travelling very fast, in the opposite direction of Earth orbit, and our spacecraft are not able to catch it even if we had one ready for launch today.

To solve this in the future, the European Space Agency (ESA) is preparing the Comet Interceptor mission.

It will lie in wait for a suitable target from a parking orbit, potentially aiming for a pristine comet from the distant Oort Cloud that surrounds our Solar System, or another interstellar object like 3I/ATLAS.

“When Comet Interceptor was selected in 2019, we only knew of one interstellar object – 1I/ʻOumuamua, discovered in 2017.

Since then, two more such objects have been discovered, showing a large diversity in their appearance. Visiting one could provide a breakthrough in understanding their nature.”

Michael Kueppers – Comet Interceptor project scientist

Investing in Space Exploration

Intuitive Machines

Sending probes to interstellar objects is going to require a strong expertise in building large space probes and making them arrive in the right place intact. For now, this has been mostly the domain of public institutions like NASA, the ESA, and associated universities.

This is changing as we are getting closer to the point where private companies could start sending automated or manned missions to mine asteroids, especially near-Earth objects.

This sort of project will likely be the next step or done in parallel to the return of manned missions to the Moon, planned for the upcoming years.

Founded in 2013 in Houston, Texas, Intuitive Machines is, for now, a very “Moon-focused” company, as indicated by its stock ticker LUNR, and has already been selected for 4 NASA lunar missions, and employs 400+ people.

Source: Intuitive Machines

It was the first commercial company to successfully land and transmit scientific data from the Moon. It also performed the 1st firing of the LOx/LCH4 (liquid oxygen, liquid methane) engine in space.

The company is working on many projects that will form the base of a lunar infrastructure for exploration and settlement.

The first one is the “data transmission service”, with the technology being tested, and ultimately looking to end with a lunar data transmission constellation around the Moon’s orbit.

Source: Intuitive Machines

The second part is the “Infrastructure as a Service”. It should include an LTV capable of autonomous operations, the telecommunication service, and GPS localization services.

Source: Intuitive Machines

The last segment is the delivery of material to the lunar surface. So far, the company has delivered scientific payloads with the Nova-C lander, a 4.3-meter-tall lander (14-feet) able to deliver 130kg of payload to the Moon.

The next step will be with the Nova-D lander, able to deliver 1,500-2,500 kg of material to the Moon. This payload capacity and size will be the one required for delivery of the Lunar Terrain Vehicle (LTV), as well as the 40kW Fission Surface Power nuclear reactor expected to power the Moon base.

Source: Intuitive Machines

The company has landed many valuable contracts with NASA, for example, the Near Space Network contract, with a maximum potential value of $4.82B.

The LTV contract final decision by NASA between the 3 potential suppliers is expected for the end of 2025, and would be worth up to $4.6B as well.

Besides NASA, the company is trying to diversify its client base, having been selected in April 2025 for a grant of up to $10M by the Texas Space Commission. This will support the development of an Earth reentry vehicle and orbital fabrication lab designed to enable microgravity biomanufacturing.

This reentry vehicle will also provide a backup option and reduce risks for the Company’s future lunar sample return missions.

Another project is the development of low-power nuclear stealth satellites for an Air Force research laboratory JETSON contract.

As the company reaches a positive free cash flow point in Q1 2025, and with the lunar telecommunication contract, it is now becoming a lot safer for investors, moving away from a cash-burning startup to an established services provider to the growing space economy.

And it could form the building block of further deep space exploration and utilization of space resources, especially as it becomes a trusted partner of NASA on par with SpaceX or Rocket Lab (RKLB +1.05%).

Study Referenced:

^{1. Adam Hibberd, Adam Crowl, Abraham Loeb. Is the interstellar object 3I/ATLAS alien technology? International Journal of Aerodynamic Control & Aviation Mechanics. Volume 1 Issue 1- 2025. https://arxiv.org/pdf/2507.12213}