how close will 3i atlas come to earth

Comet 3I/ATLAS will come closest to Earth on December 19, 2025, at a distance of about 1.8 astronomical units (AU), which is approximately 270 million kilometers or 170 million miles. This distance means it will come relatively close on a cosmic scale but poses no threat to Earth. The comet will pass between the orbits of Earth and Mars at its closest approach to the Sun, which occurs around October 29, 2025, at a distance of about 1.36 AU (203 million km) from the Sun. Prior to its closest approach to Earth, 3I/ATLAS will make a close pass near Mars at about 0.19 AU (28 million km) on October 3, 2025.