Interstellar Intruder: NASA discovers rare comet from outside our solar system

Mint

04-07-2025

The National Aeronautics and Space Administration (NASA) has discovered a rare interstellar comet. It has been officially named 3I/ATLAS.
Comet 3I/ATLAS was discovered on July 1 and spotted by a Chile-based survey telescope named ATLAS (Asteroid Terrestrial-impact Last Alert System).
According to Reuters, astronomers are tracking a newly spotted comet hailing from parts "unknown".
"It came from outside our solar system and right now, it's inside the orbit of Jupiter, and it is headed for its closes pass to the sun at the end of October," said Davide Farnocchia, a navigation engineer with NASA's Center for Near Earth Object Studies (CNEOS).
NASA said that the comet originated from interstellar space (space between the stars) and is arriving from the direction of the constellation Sagittarius.
The comet is currently located about 420 million miles (670 million kilometers) away. It is journeying at a speed of around 37 miles (60 km) per second from the direction of the center of the Milky Way galaxy.
"It was first detected as a speck of light moving relative to background stars," Davide Farnocchia said. "It's gonna pass, visit us, and then on its way out and leave the solar system in the future," he added.
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Astronomers said its unusual trajectory indicated it had ventured from beyond our solar system.
"This rare visitor from beyond our solar system was spotted this week, and the global astronomy community is racing to collect more data," NASA JPL wrote in an Instagram post.
The spotting of Comet 3I/ATLAS is the third time such an interstellar object has been observed visiting our solar system.
The only other such interstellar visitors previously observed by astronomers were objects called 1I/'Oumuamua (pronounced oh-MOO-uh-MOO-uh), detected in 2017, and 2I/Borisov, discovered in 2019.
NASA said the comet poses no threat to Earth and will remain at a distance of at least 1.6 astronomical units (about 150 million miles or 240 million km).
The comet, 3I/ATLAS, will, however, reach its closest approach to the Sun around October 30, at a distance of 1.4 au (about 130 million miles or 210 million km) — just inside the orbit of Mars.
While NASA JPL refused to comment on the comet, University of Hawaii astronomer Larry Denneau said on Thursday, "The comet has some similarities to 2I/Borisov in that it appears to be an icy comet."
Denneau, co-principal investigator for ATLAS, noted that the comet 'is much larger, possibly 10 km (6.2 miles) in diameter.'
Larry Denneau said comet 3I/ATLAS currently has a faint coma, referring to the cloud of gas and dust surrounding a comet's nucleus. "But the coma and tail may increase dramatically as the object comes closer to the sun," he was quoted by Reuters as saying.
This is a golden opportunity for astronomers to study a pristine object from another star system.
NASA's Davide Farnocchia said, "We're really excited about these objects," while mentioning that so far, "we've discovered three interstellar objects.
"So it's a rare opportunity, and as a scientific community, we want to collect as much data as possible to characterise these objects and learn as much as we can," he said.
Meanwhile, Denneau said, "Its closest approach to the sun will be later this year, when it will come inside the orbit of Mars. We don't know what will happen, so that's exciting."