By STACY LIBERATORE, U.S. SCIENCE & TECHNOLOGY EDITOR
The appearance of a mysterious interstellar object has reignited debate over whether extraterrestrial technology could be hiding in our solar system.
NASA detected the object, dubbed 3I/ATLAS, on July 1, sparking a flurry of scientific analysis to determine its origin.
While more than 200 researchers have concluded it is likely a comet, Harvard physicist Avi Loeb has raised doubts in a newly released pre-print paper, pointing to one glaring omission: 3I/ATLAS has no visible tail.
‘There were claims of a tail,’ Loeb said, ‘but since 3I/ATLAS is accelerating and its current size is not much larger than the angular resolution of Earth-based telescopes, it is not easy to avoid fictitious elongation of the image as a result of the object’s motion.’
He also questioned the object’s unusual lack of gas emissions and its precise, retrograde trajectory, which aligns suspiciously well with the inner solar system.
Loeb has developed what he calls the ‘Loeb Scale’, a ranking system to evaluate the likelihood that an object is artificial, and gave 3I/ATLAS a six out of ten.
That suggests it is more likely than not to be engineered, though he emphasized that this score may change as more data becomes available.
Among his more provocative theories, Loeb suggested 3I/ATLAS could be an alien mothership releasing small probes to intercept Earth.
The interstellar object (circled) is believed to be a comet, but Harvard astrophysicist Avi Loeb contends it could be an alien craft
‘The more likely scenario from an engineering perspective involves a mothership that releases mini-probes which perform a reverse Oberth maneuver to slow down at perihelion and intercept Earth,’ Loeb wrote.
This type of maneuver uses the sun’s gravitational pull at the object’s closest approach to adjust the trajectory efficiently, enabling the probes to reach Earth without large amounts of fuel.
According to Loeb, these hypothetical probes could arrive between November 21 and December 5, 2025, based on 3I/ATLAS’s expected position behind the sun in October, an ideal window for a covert approach.
‘It may come to save us or destroy us,’ he said. ‘We’d better be ready for both options and check whether all interstellar objects are rocks.’
Chris Lintott, an astronomer at the University of Oxford, dismissed Loeb’s theory as ‘nonsense on stilts,’ calling it ‘an insult to the exciting work going on to understand this object.’
However, Loeb said his analysis remains rooted in observational data.
His latest paper, based on ground-based telescope readings between July 2 and 29, revealed reddening colors in 3I/ATLAS, usually interpreted as surface dust or organic compounds.
He noted that spectroscopic data from this and three previous studies show no signs of atomic or molecular gas in a coma, a feature typically expected in comets.
Images of 3I/ATLAS taken on July 4 and July 29, 2025, show no sign of a comet tail. The arrows in the images indicate the directions of the sun, north, east and the way the object is moving through space
While the reddening may suggest dust, it could also mean the object simply has a naturally red surface, much like D-type asteroids or other ancient space rocks.
‘Continued monitoring around perihelion is necessary to track changes in activity and color,’ the study concluded, ‘which will provide insights into the evolution of interstellar materials under solar radiation.’
Loeb has authored four scientific papers on 3I/ATLAS and recently proposed using NASA’s Juno spacecraft to intercept the object near Jupiter in 2026, calling it a rare opportunity for ‘interstellar archaeology.’
He also believes governments should already be forming task forces, including scientists, policymakers and even psychologists, to determine how to respond and how to break the news to the public without triggering panic.
If 3I/ATLAS is more than just a rock, he said, Earth is woefully unprepared.
‘The visitor,’ he warned, ‘is already in our backyard.’
Even if the object turns out to be artificial, Loeb admitted there’s little humanity could do.
At nearly 60 miles per second relative to Earth, it’s moving far too fast for any of our current rockets to reach.
Telescopes have been tracking the course of 3I/ATLAS as it travels through our solar system in 2025 and 2026
Loeb has remained adamant that something about 3I/ATLAS does not add up. He said its retrograde orbit, meaning it’s moving against the flow of the solar system, is oddly aligned with Earth’s path
‘If the hypothesis that 3I/ATLAS is a technological artifact proves correct, there are two possible implications: either its intentions are entirely benign, or they are malign, said Loeb.
‘In the first case, humanity needs only to wait and welcome this interstellar messenger with open arms. It is the second scenario that causes serious concern.’
He added that because the second possibility has serious consequences, we can use the idea behind Pascal’s wager.
‘Blaise Pascal argued that it’s smarter to believe in God because the possible benefits of believing are much greater than the losses if you’re wrong,’ Loeb explained.
‘Similarly, in our case, it makes sense to warn humanity about the risk from 3I/ATLAS, even if it turns out to be just a theory.
‘The cost of not warning could be much worse than the cost of being wrong.’
This article was originally published by a www.dailymail.co.uk . Read the Original article here. .