Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for being a planet, putting Pluto into the new category of dwarf planet Pluto was considered the solar system's ninth planet for more than 70 years. NASA / JHU-APL / SwRI For decades, scientists and the general public have argued over the astronomical status of beloved dwarf planet Pluto . In the latest salvo, NASA Administrator  Jared Isaacman said that he was “very much in the camp of ‘make Pluto a planet again,’” during a Senate hearing on April 28. Isaacman’s statement highlights the longstanding debate over Pluto’s classification. His remarks were made during a hearing over the Trump Administration’s proposed  budget cuts to NASA. Pluto was discovered by American astronomer Clyde Tombaugh in 1930 at an observatory in Flagstaff, Arizona.…