Months after ground telescopes on Earth discovered the third interstellar object infiltrating our Solar System, scientists are raising concerns that it may be more than that.
The object named 3I/ATLAS is set to make a close pass near Jupiter on March 16, 2026, at approximately 53.5 million kilometers. The arrival of this rare visitor from beyond our solar system has spurred scientists to consider an unprecedented move: rerouting Nasa’s Juno spacecraft, currently orbiting Jupiter, to intercept and study the object up close.
Discovered in July 2025, 3I/ATLAS is the third confirmed interstellar visitor traversing our solar system, following ‘Oumuamua and Comet Borisov. It is notable for its large nucleus, estimated at around 5.6 kilometers in diameter, and its high speed of 58 km/s relative to the Sun.
Unlike prior interstellar visitors, 3I/ATLAS’s trajectory will bring it relatively close to Jupiter, offering a unique opportunity for direct scientific investigation.
The plan, proposed in a draft paper, involves a precise engine burn by Juno on September 9, 2025, to adjust its orbit around Jupiter. Utilising a gravity-assisted “Jupiter Oberth Manoeuvre,” Juno would gain the velocity and directional change needed to intercept 3I/ATLAS about two days before the comet’s closest approach to Jupiter, potentially as near as 27 million kilometers.
This manoeuvre is fuel-efficient, requiring only about 110 kg of Juno’s remaining propellant, just 5.4% of its original fuel load.
Currently, Juno is equipped with advanced instruments capable of probing 3I/ATLAS’s composition and behaviour. These include a near-infrared spectrometer, magnetometer, microwave radiometer, and cameras that together could reveal the object’s makeup and the nature of its coma and dust tail—details unattainable from Earth-based telescopes.
Insights gained could dramatically deepen understanding of interstellar visitors and their origins, shedding light on the properties of materials from other star systems.
There is also speculative intrigue around the nature of 3I/ATLAS, with some discussions about whether such interstellar travellers could be natural objects or potentially artificial probes.
While this remains unconfirmed, the ability for Juno to closely observe 3I/ATLAS could provide critical data to clarify its nature.
This mission extension could both rejuvenate Juno’s scientific lifespan and represent a new frontier in interstellar object exploration, capitalising on a rare celestial visitor as it journeys through our cosmic neighbourhood.
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