when will 3i atlas be closest to earth

3I/ATLAS will be closest to Earth on December 19, 2025, when it will pass at a distance of about 1.8 astronomical units (approximately 269 million kilometers or 167 million miles) from Earth. Prior to that, it will reach perihelion (its closest approach to the Sun) on October 29, 2025, at a distance of 1.36 AU, which is between the orbits of Earth and Mars. It also will pass closer to Mars on October 3, 2025, at about 0.19 AU (28.98 million km) but will not come as close to Earth itself during its journey through the Solar System.