Interstellar object 3I/ATLAS passed Mars last night
Key Takeaways
- Interstellar object 3I/ATLAS made its closest approach to Mars on October 3, 2025, at a distance of about 18 million miles.
- NASA and ESA are coordinating observations of 3I/ATLAS using multiple spacecraft orbiting Mars, including MRO, Mars Express, and ExoMars TGO.
- This Mars flyby was the closest approach the object will make to any planet during its trajectory through the solar system.
- 3I/ATLAS will reach perihelion (closest point to the Sun) on October 29, 2025.
- ESA's Juice spacecraft is scheduled to observe the comet in November, potentially capturing the best views of its active state.
The third known interstellar object, comet 3I/ATLAS, recently made its closest approach to Mars at 4 UTC on October 3, 2025, passing approximately 18 million miles away. This marked the object's closest approach to any planet during its single passage through our solar system. In response, space agencies including NASA and ESA are coordinating extensive observation campaigns using assets like the Mars Reconnaissance Orbiter, Mars Express, and ExoMars Trace Gas Orbiter to gather detailed data. The object is scheduled to reach perihelion, its closest point to the sun, on October 29, 2025. Furthermore, ESA's Jupiter Icy Moons Explorer (Juice) is slated to observe 3I/ATLAS in November, likely providing the best views of the comet when it is most active. The object originated from the direction of the Sagittarius constellation in the Milky Way galaxy, though its specific home system remains unknown.
