A rare interstellar object, Comet 3I/Atlas, is hurtling through our solar system, igniting a scientific debate about its nature and potential implications.
Discovered on July 1 by the Asteroid Terrestrial-Impact Last Alert System (Atlas) survey telescope in Río Hurtado, Chile, it is only the third known object from outside our solar system to pass through, reported The Guardian.
While NASA scientists assert it is a natural comet, Harvard astronomer Avi Loeb has proposed a provocative hypothesis that it could be an artificially made artifact with potentially serious consequences for Earth.
A controversial hypothesis
Avi Loeb, head of Harvard University’s Galileo Project, which searches for evidence of extraterrestrial intelligence, has suggested that Comet 3I/Atlas could be a technological artifact. In a scientific paper published in July, Loeb noted that the object lacks the gaseous tails of dust and plasma typical of comets from our solar system and follows an unorthodox trajectory, hinting at “active intelligence.”
“[If] future data will indicate the absence of a cometary tail, we will be faced with the tantalizing possibility that it did not inherit a random velocity in interstellar space but instead was sent towards the inner solar system by design,” Loeb wrote in a blog post.
He further speculated that the object might perform a clandestine maneuver behind the sun in late October, potentially setting a course for Earth with “malign intent.”
NASA’s rebuttal
NASA scientists have dismissed Loeb’s claims, asserting that Comet 3I/Atlas is a natural body. The agency has been studying the object using ground and space telescopes since its discovery and has found no evidence of a threat to Earth.
“It looks like a comet. It does comet things. It very, very strongly resembles, in just about every way, the comets that we know,” said
Tom Statler, NASA’s lead scientist for solar system small bodies.
Statler emphasised that the comet’s behavior aligns with known cometary characteristics, despite some unique properties. “It has some interesting properties that are a little bit different from our solar system comets, but it behaves like a comet. And so the evidence is overwhelmingly pointing to this object being a natural body. It’s a comet.”
Characteristics of Comet 3I/Atlas
Imagery from the Hubble Space Telescope indicates that Comet 3I/Atlas is up to 3.5 miles (5.6km) wide and is traveling at an unprecedented 1,30,000 mph (2,09,000 km/h), the highest velocity ever recorded for a solar system visitor. It is set to make close passes with Mars, Jupiter, and Venus, but will not come closer to Earth than approximately 170 million miles due to planetary alignments in the coming months.
Statler explained that comets, including interstellar ones, often exhibit unpredictable behavior. “Comets are mixtures of dust and ice; they’re being heated by the sun, that heating is changing, and exactly how they respond to that is something that’s a bit unpredictable,” he said.
He added that sudden brightening, caused by sublimating ice or dust release, is common among comets and provides opportunities for further study.
A window into other solar systems
The discovery of Comet 3I/Atlas is significant not only for its rarity but also for the scientific opportunities it presents. “It’s special because we now can discover these interstellar comets,” Statler said. “It’s not that they’re really anything new, but we’ve just recently had the ability to discover them, and we’ve discovered only three so far. This gives us a window we’ve never had before, directly into the composition of other solar systems.”
