Interstellar Object 3I/Atlas Passed Mars Last Night

Summary

Here is interstellar object 3I/ATLAS approaching Mars on October 2, 2025. This simulated image is from NASA’s Eyes on the Solar System tool. The world’s 3rd known interstellar object – 3I/ATLAS – has made its closest approach to Mars. The approach took place at 4 UTC on October 3, 2025 (11 p.m. CDT on October 2). At that time, the comet was approximately 18 million miles (29 million kilometers) from Mars. It was the object’s closest approach to any planet during its one-time journey through our solar system. As of this writing (10 UTC on October 3), we have not seen any new images from the pass. But multiple space agencies, including NASA and the European Space Agency (ESA), are coordinating observations using various spacecraft and orbiters around Mars. Instruments on ESA’s Mars Express and ExoMars Trace Gas Orbiter, as well as NASA’s Mars Reconnaissance Orbiter, are focusing on capturing detailed data from this interstellar visitor. In an October 2 story from AP, Marcia Dunn reported: Both of the European Space Agency’s satellites around Mars are already aiming their cameras at the comet, which is only the 3rd interstellar object known to have passed our way. NASA’s satellite and rovers at the red planet are also available to assist in the observations. Previously, Marshall Eubanks of Space Initiatives had said: During the Mars close approach, the Mars Reconnaissance Orbiter will observe 3I with HiRISE, observing between 1 – 4 a.m. on October 2, and the CaSSIS camera on ESA’s Trace Gas Orbiter and the Mars Express’ High Resolution Stereo Camera will be observing on October 3. 3I/ATLAS will reach perihelion, its closest point to the sun, on October 29, 2025. Its perihelion distance will be roughly 1.36 astronomical units (AU) from the sun – just inside the orbit of Mars. If you’re interested in tracking the object, NASA’s Eyes on the Solar System tool offers interactive simulations of its path. Also, NASA just launched a new page devoted to 3I/ATLAS. And the latest...