Interstellar Comet 3I/ATLAS Passes Mars Orbit at High Speed

Comet 3I/ATLAS, the third known interstellar visitor to our solar system, was discovered in early July 2025 and is currently being closely tracked by astronomers worldwide. Traveling at over 220,000 kilometers per hour, this comet is larger and faster than previous interstellar objects like ʻOumuamua and Borisov, measuring about 20 miles (approximately 32 kilometers) wide. Recent modeling by astronomers, including Matthew Hopkins and Chris Lintott, suggests that 3I/ATLAS originates from a different region of the galaxy than prior interstellar visitors, providing unique insights into the galaxy’s population of such objects. The comet will make its closest approach to the Sun on October 30, 2023, passing inside Mars's orbit but remaining safely distant from Earth, and is expected to be observable with ground-based telescopes until September and again in December. As an active comet, it is forming a glowing coma and tail as it heats up, allowing scientists to study material from another star system firsthand. This discovery offers a rare opportunity to learn about planetary system formation beyond our own solar system.