Largest & Oldest Interstellar Comet Ever Seen Nears Sun – 3I/ATLAS Blasts Water ‘Like a Fire Hose’
Comet 3I/ATLAS, discovered July 1, 2025, is the third known interstellar object to enter our solar system. It will pass closest to the Sun on October 29–30, 2025, but will not be visible from Earth. The comet is traveling over 130,000 mph and may be up to 5–10 km wide, making it the largest interstellar visitor detected. Observations show strong water outgassing and a coma rich in carbon dioxide.