Comet 3I/ATLAS

3I/ATLAS (C/2025 N1) is the third confirmed interstellar object to pass through our solar system. It was discovered on July 1, 2025 by the ATLAS survey in Hawaii, and was confirmed interstellar the next day due to its hyperbolic trajectory and retrograde motion.

This icy comet likely originated from a distant star system and is now making flybys of Mars, Venus, Earth, and Jupiter between October 2025 and March 2026. With a diameter of 5–6 km and mass over 33 billion tons, it’s far larger than previous interstellar visitors and shows active outgassing.

Scientists are tracking it with NASA, Hubble, and JWST, hoping to learn more about its composition. Some speculate it could be a technological artifact, though this remains unproven.