3I/ATLAS is an interstellar comet that recently passed its closest approach to the Sun around late October 2025 and did not come close to Earth. It was expected to reach perihelion around October 30, 2025, at roughly 1.4 AU from the Sun, with subsequent flybys including a distance of about 1.8 AU from Earth on October 29–December 2025 timeframe, depending on the exact trajectory. For observers on Earth, the object remained too faint to see with the naked eye and required telescopes to track as it moved past the inner Solar System. Direct answer to your query:
- When is 3I/ATLAS passing Earth? There is no close Earth passage for 3I/ATLAS. Its trajectory is hyperbolic and it passed through the inner Solar System on a path that did not bring it within a few million kilometers of Earth, with the closest Earth-side approaches occurring at distances well outside naked-eye visibility. In late October 2025 it reached perihelion near the Sun and then receded; the closest approach to Earth occurred earlier in its journey or later in its outbound phase at distances around a few hundred million kilometers, not a close encounter. It poses no threat to Earth.
