Astronomers are closely observing 3I/ATLAS, a rare object from beyond our solar system that will move past the Sun on October 29. Getty Images
An unusual object from another star system is drawing attention from astronomers around the world. The object, named 3I/ATLAS, will reach its closest point to the Sun, known as perihelion, on October 29. Earlier this week, it moved directly behind the Sun from Earth’s point of view — a position called solar conjunction — making it invisible to our telescopes for now.
Scientists believe 3I/ATLAS is a comet made mostly of frozen carbon dioxide, similar to others that have travelled through our solar system. However, one well-known astronomer has a far more extraordinary theory.
A Bold Theory from Harvard
Harvard astrophysicist Avi Loeb thinks there’s a small chance the object is not a comet at all — but a giant alien spacecraft. Loeb, known for his curiosity about interstellar visitors, says 3I/ATLAS behaves too strangely to ignore.
He notes its massive size, unusual path through space, and its close pass near Mars earlier this month. Loeb believes the object’s timing and movements might suggest intelligent design rather than a random orbit.
In a recent interview, Loeb joked, “If you want to take a vacation, take it before October 29, because who knows what will happen?”
Using the Sun for a Space Boost
Loeb explained his reasoning using a real concept from physics known as the Oberth effect. This principle shows that a spacecraft gains more energy if it fires its engines while moving fastest — usually near a star or planet.
He believes if 3I/ATLAS were truly a spacecraft, it could be using the Sun’s gravity to speed up or slow down, possibly while hiding behind it.
Loeb also speculates that the object might release small probes while near the Sun to study planets in our solar system. “If 3I/ATLAS is a massive mothership,” he wrote, “it will likely continue along its path and exit the solar system, but it might release smaller crafts at perihelion.”
The Scientific Debate
Not everyone agrees with Loeb’s bold theory. Many scientists insist the object is just a natural comet.
“It looks like a comet. It acts like a comet,” said NASA scientist Tom Statler. “It very strongly resembles the comets we already know.”
Even Loeb admits that the odds of 3I/ATLAS being alien-made are small. Still, he believes science should stay open-minded. “Science is guided by evidence, not expectations,” he wrote.
Loeb plans to monitor the sky in November and December to look for any strange activity — such as pieces breaking off or changes in direction.
“As of now, 3I/ATLAS appears most likely to be a natural comet,” he said. “But even a tiny chance of something else is worth watching — because if it isn’t natural, the discovery would change everything.”
