when is 3i atlas passing earth

Comet 3I/ATLAS already made its closest pass to Earth on December 19, 2025, and it is now heading back out of the solar system on a one‑time flyby.

Key timing details

• 3I/ATLAS is an interstellar comet (also known as C/2025 N1) passing through the solar system only once on a hyperbolic path, so it will not return.

• Its closest approach to the Sun (perihelion) was on October 29, 2025, at a distance of about 1.36 AU, between the orbits of Earth and Mars.

• Its closest approach to Earth occurred on December 19, 2025, at about 1.8 AU (roughly 168–270 million km / 167–170 million miles), nearly twice Earth’s distance from the Sun.

Visibility and safety

• Even at closest approach, 3I/ATLAS was far too faint and distant to be seen with the naked eye; viewing required at least a decent telescope and dark skies.

• At no point did it pose any impact risk to Earth, as its trajectory kept it well beyond the orbits of the inner planets during its flyby.

What happens next

• 3I/ATLAS is now moving back out through the outer solar system and will continue into interstellar space, not remaining bound to the Sun’s gravity.

• Astronomers are using observations from spacecraft and ground‑based telescopes to study its composition and motion, hoping to learn more about material from other star systems.

Information gathered from public forums or data available on the internet and portrayed here.