Astronomers have confirmed the discovery of 3I/ATLAS, the third known interstellar object to traverse our solar system. The comet was first detected on July 1, 2025, by the ATLAS telescope in Rio Hurtado, Chile.
Initially designated A11pl3Z, the object has been classified as a comet due to the presence of a coma and a short tail observed in recent images. Its estimated size ranges from 10 to 20 kilometers in diameter, making it the largest interstellar object detected to date.
3I/ATLAS follows a hyperbolic trajectory, indicating it is not gravitationally bound to the Sun and originates from interstellar space. It is expected to reach its perihelion, the closest point to the Sun, around October 29, 2025, passing at a distance of approximately 1.4 astronomical units (AU), or 210 million kilometers, just inside the orbit of Mars.
Despite its proximity to the Sun, 3I/ATLAS poses no threat to Earth, as its trajectory will take it to a safe distance from our planet. Astronomers continue to monitor its movement to gain more information about its composition and characteristics.
This discovery highlights the importance of surveillance programs like ATLAS, which allow for the detection and study of objects that come from outside our solar system, expanding our knowledge of the cosmos.