A comet traveling outside the solar system and heading toward the Earth is much larger than scientists first believed, a scientist has detailed in a new report. The object, named 3I/ATLAS, is only the third interstellar visitor ever detected, after Oumuamua in 2017 and 2I/Borisov in 2019. The astrophysicist also revealed in a Medium blog post that new data and measurements indicate the comet’s nucleus is more massive than first estimated. ASTRONOMERS MAKE GROUNDBREAKING DISCOVERY ABOUT LARGEST COMET EVER OBSERVED FLYING THROUGH DEEP SPACEThe comet dwarfs Oumuamua, just a quarter-mile long, and Borisov, about 0.6 miles across. (Getty Images) Expand"This makes 3I/ATLAS three to five orders of magnitude more massive than the previous two interstellar objects we’ve observed," Loeb wrote in his post .