Third-ever interstellar object spotted zooming through our solar system
Third-ever interstellar object spotted zooming through our solar system
In a rare astronomical event, astronomers have confirmed the passage of an interstellar object through our solar system.
Officially designated as 3I/ATLAS (also known as C/2025 N1), the comet-like body was first detected on Tuesday.
The International Astronomical Union's Minor Planet Center classified it as interstellar on July 2 after analyzing its trajectory and initial observations.
An interstellar object is one that is not orbiting the Sun and will eventually exit our solar system.
3I/ATLAS is not bound by the Sun's gravity
The 3I/ATLAS is not bound by the Sun's gravity, confirming its origin from outside our solar system.
It was first detected by NASA's ATLAS survey in Hawaii under the temporary designation A11pl3Z.
3I/ATLAS is classified as a comet due to its icy composition.
Only two interstellar objects like this have ever been confirmed before: 'Oumuamua in 2017 and Comet 2I/Borisov in 2019.
3I/ATLAS is estimated to be between 10-20km in diameter
The 3I/ATLAS is estimated to be between 10-20km in diameter, possibly making it the largest interstellar object ever detected.
Richard Moissl from the European Space Agency's planetary defense team said it's racing through the solar system at a blistering speed of over 60km/s.
It will reach perihelion (closest approach to Sun) in October 2025 at about two AU (twice Earth-Sun distance).
Will pass just inside Mars's orbit
The 3I/ATLAS comet will pass just inside Mars's orbit without posing any threat to Earth.
Physicist Marshall Eubanks said it could come close enough to be detected by the Mars Reconnaissance Orbiter.
By April 2026, it is expected to reach a speed of 90km/s relative to Earth, possibly breaking records for the fastest flyby ever recorded.
Currently too faint to see; expected to brighten soon
Presently visible only from the Southern Hemisphere, the 3I/ATLAS has a visual magnitude of around 18.8, making it difficult to see with the naked eye.
However, advanced telescopes may be able to capture it as its brightness increases to magnitude 16 by August.
Astronomer Eddie Irizarry has released star charts showing the comet's expected path through the constellation Sagittarius.
Many more such interstellar objects may exist out there
The 3I/ATLAS will remain observable with powerful telescopes into next year, gradually fading as it exits the solar system.
Some models suggest that thousands of such objects may drift through at any given time, most too small or dim to detect.
Mark Norris from the University of Central Lancashire said these interstellar visitors offer a unique opportunity to study samples from beyond our own star system.