Pluto was discovered in 1930, four years before Holst's death, and was hailed by astronomers as the ninth planet.
In the March 1972 final broadcast of his Young People's Concerts series, conductor Leonard Bernstein led the New York Philharmonic through a fairly straight interpretation of the suite, though Bernstein discarded the Saturn movement because he thought the theme of old age was irrelevant to a concert for children.