The interstellar comet 3I/ATLAS will not actually reach Earth. Its closest approach to Earth is projected to be about 1.8 astronomical units (approximately 170 million miles or 270 million kilometers) away, occurring in December 2025. It passed closest to Mars on October 3, 2025, and will continue on its path through the solar system, passing within 1.36 AU of the Sun on October 29, 2025, before heading away from Earth and out of the solar system. Therefore, 3I/ATLAS will never come close enough to "reach" Earth or pose any threat to it.