If 3I/ATLAS is a technological artefact, its trajectory could reflect deliberate navigation. Photo credit: Domenichini Giuliano/Shutterstock
3I/ATLAS is the third confirmed interstellar object known to enter our Solar System, following ʻOumuamua and 2I/Borisov. Discovered on 1 July 2025 by the ATLAS survey telescope, its hyperbolic trajectory confirms an origin beyond our planetary neighbourhood. Given its size, speed and unusual orbit, astronomers worldwide have prioritised monitoring it to understand the nature and composition of material from other star systems.
NASA and major observatories classify 3I/ATLAS as comet-like in appearance. Observations reveal a dust-rich coma and tail, typical of a comet when volatile ices sublimate near the Sun. These features are consistent with standard comet models, where gas and dust jets generate minor but measurable non-gravitational acceleration. Yet despite these conventional indicators, 3I/ATLAS has become the centre of intense scientific and public debate.
The deviation that reignited speculation
The trajectory anomaly and the Jupiter question
Recent observations have generated speculation that 3I/ATLAS is more than a typical comet. According to Davide Farnoccia, navigation engineer at NASA’s Jet Propulsion Laboratory (JPL), the object deviated four arcseconds in right ascension from the trajectory expected under the influence of solar gravity alone. This apparent non-gravitational acceleration has prompted some scientists, including Harvard astrophysicist Avi Loeb, to hypothesise that 3I/ATLAS could have a technological origin and “may have adjusted its trajectory with the help of thrusters to reach Jupiter’s Hill sphere,” where the gas giant’s gravity dominates over the Sun’s.
While mainstream astronomers emphasise that cometary outgassing could explain minor deviations, this anomaly forms the basis of more speculative interpretations.
Avi Loeb and the alien probe hypothesis
Why Loeb believes this could be more than a comet
Avi Loeb, a theoretical physicist, cosmologist and professor at Harvard university known for advocating the search for extraterrestrial life, has suggested that 3I/ATLAS may be an engineered object. Loeb highlights that its perihelion occurred while the object was hidden behind the Sun, complicating Earth-based tracking. This timing raises the possibility of undetectable manoeuvres or even the release of technological devices in Jupiter’s orbit.
Loeb argues that if satellites or other artefacts of non-human origin were discovered near Jupiter, it would imply that the planet is of interest to extraterrestrial civilisations. Conversely, a lack of similar devices near Earth could suggest our planet is not a focus, carrying implications for both scientific understanding and philosophical reflection on humanity’s place in the cosmos.
Jupiter: a strategic target for exploration
Why the gas giant repeatedly emerges in speculation
Jupiter’s massive gravity well makes it an ideal location for any object to perform a gravitational slingshot, alter speed, or deploy orbiting probes. If 3I/ATLAS is a technological artefact, its trajectory could reflect deliberate navigation rather than coincidence. Loeb calculates that missions such as Juno could potentially detect such satellites, providing evidence to confirm or refute the technological hypothesis.
While mainstream science remains cautious, the very suggestion encourages closer observation of the interstellar visitor as it passes through the Jovian system.
Summary of the 3I/ATLAS debate
- 3I/ATLAS is the third confirmed interstellar object to enter the Solar System, discovered in July 2025.
- Davide Farnoccia (NASA JPL) reported a four-arcsecond deviation in right ascension, unexplained by solar gravity alone.
- Observations suggest minor non-gravitational accelerations typical of cometary activity, yet some speculate technological origins.
- Avi Loeb posits the object may have used thrusters to approach Jupiter’s Hill sphere and could deploy satellites there.
- Loeb emphasises that this is speculative and intended to prompt further investigation, not assert alien origin.
- Mainstream astronomy continues to support a natural explanation based on comet physics and outgassing behaviour.
Conclusion: a cosmic riddle, comet, probe, or something between?
3I/ATLAS remains a fascinating mystery. To most scientists, it is a rare interstellar comet providing insights into planetary formation beyond our Solar System. To others, it represents a potential technological alien artefact with a trajectory hinting at Jupiter as a strategic point of interest.
Whether confirmed as a natural comet or something more extraordinary, 3I/ATLAS has reignited global discussion about how we recognise the extraordinary when it enters our cosmic neighbourhood, offering both scientific insight and a humbling perspective on our place in the galaxy.
