This planet and Earth are the only ones whose atmospheres are mostly nitrogen. Pictures of it were taken during a search for the hypothetical Planet O. Perceval Lowell predicted the presence of this p
This planet and Earth are the only ones whose atmospheres are mostly nitrogen. Pictures of it were taken during a search for the hypothetical Planet O. Perceval Lowell predicted the presence of this planet discovered by Clyde Tombaugh ("TOM-baw"). Charon has long been considered its satellite, though that classification is now ambiguous. For 10 points, name this celestial object, recently relegated to the category of "dwarf planet."
This planet and Earth are the only ones whose atmospheres are mostly nitrogen.
{Pluto}