Res 0628-2026

Res. No. 628 ..Title Resolution calling on the New York City Department of Education to commemorate the 20th anniversary of the reclassification of Pluto as a dwarf planet by encouraging age-appropriate instruction and educational programming on Pluto’s discovery, classification history, and the ongoing scientific debate over its planetary status ..Body By Council Member Morano Whereas, On February 18, 1930, Clyde Tombaugh, a self-taught American astronomer who had built his own telescope and whose drawings of Jupiter and Mars so impressed the staff of Lowell Observatory in Flagstaff, Arizona that they hired him to search for a theorized ninth planet, discovered Pluto using a 13-inch telescope and a blink comparator to identify moving celestial bodies against photographic plates; and Whereas, The discovery was officially announced by the Lowell Observatory on March 13, 1930, and on May 1, 1930, the object was officially named Pluto, at the suggestion of an eleven-year-old English girl, Venetia Burney Phair; and Whereas, For the next 70 years, Pluto was recognized as the ninth planet in the solar system, even as some astronomers, beginning shortly after its discovery, questioned whether the newly found body was massive enough to merit planetary status; and Whereas, In February 2000, the American Museum of Natural History (AMNH) in New York City (NYC) opened its newly redesigned Hayden Planetarium as part of the Rose Center for Earth and Space, with exhibits that omitted Pluto from its display of the solar system’s planets, instead grouping it with other icy bodies of the Kuiper Belt, a curatorial decision made under the planetarium’s director, Dr. Neil deGrasse Tyson; and Whereas, On January 22, 2001, The New York Times published a front-page article, reporting that the AMNH appeared to have unilaterally reclassified Pluto years before any formal scientific body had done so, drawing criticism at the time from astronomers; and Whereas, The controversy sparked by the AMNH’s exhibit decision foreshadowed the broader scientific debate that culminated, five years later on August 24, 2006, when the International Astronomical Union (IAU) adopted a formal definition of a planet that resulted in Pluto’s reclassification as a “dwarf planet,” ending its status as the ninth planet in the solar system since its discovery in 1930; and Whereas, Under the IAU’s definition, a planet must (1) be in orbit around the Sun, (2) have sufficient mass for its self-gravity to give it a nearly round shape, and (3) have “cleared the neighborhood” around its orbit of other comparably sized objects; and Whereas, Pluto satisfies the first two of these criteria but not the third, as it shares its orbital region, the Kuiper Belt, with numerous other objects of comparable size, including Eris, whose 2005 discovery prompted the IAU to take up the question of a formal planetary definition; and Whereas, The IAU’s 2006 decision has remained the subject of ongoing debate within the scientific community, with some planetary scientists, including Alan Stern, principal investigator of NASA’s New Horizons mission to Pluto, arguing for an alternative “geophysical planet definition” based on a body’s physical characteristics, such as its shape, rather than on orbital dynamics; and Whereas, As recently as 2024, planetary scientists proposed a new, more quantifiable criterion for classifying planets based on mass thresholds, an effort that, like Pluto’s reclassification before it, did not resolve the underlying debate, as Pluto did not meet the proposed mass threshold under that framework either; and Whereas, This persistent scientific debate illustrates the broader truth about the scientific process: that classification frameworks are not static, but evolve as new discoveries, data, and arguments emerge, and that open disagreement among scientists is a healthy and necessary part of how scientific understanding advances; and Whereas, Pluto’s reclassification had a significant cultural impact, particularly among the generation of students who grew up learning “My Very Educated Mother Just Served Us Nine Pizzas” (a mnemonic device used to remember the nine original planets in order from the Sun when Pluto was accepted as the ninth planet), and sparked widespread public interest in astronomy and in how scientific classification works; and Whereas, The New York State Education Department’s P-12 Science Learning Standards, which the NYC Department of Education (DOE) implements in its science curricula, include performance expectations for Earth and Space Sciences requiring students to use evidence to reconstruct the early history of the solar system and to use mathematical and computational models to predict the motion of orbiting bodies within it; and Whereas, August 24, 2026 marks the 20th Anniversary of the IAU’s reclassification of Pluto as a dwarf planet, presenting a timely opportunity for the DOE to engage students in the story of Pluto as a window into how scientific knowledge evolves and how classification frameworks are tested and refined over time; now, therefore, be it Resolved, That the Council of the City of New York calls on the New York City Department of Education to commemorate the 20th anniversary of the reclassification of Pluto as a dwarf planet by encouraging age-appropriate instruction and educational programming on Pluto’s discovery, classification history, and the ongoing scientific debate over its planetary status. CGR LS #23696 07/02/2026 5:45 PM