Pluto could be made up of billions of comets, study suggests
Dwarf planet Pluto was formed by agglomeration of roughly a billion comets, researchers have suggested based on similarities in data from NASA's Pluto probe New Horizons and ESA's Rosetta, the first-ever mission to land on a comet. Researchers found "intriguing consistency" between Pluto's nitrogen-rich ice and chemical composition of Comet 67P, leading them to propose Pluto as a "giant comet".