In a surprising twist nearly two decades after Pluto was stripped of its planetary title, NASA’s top official is leading the charge to “Make Pluto a Planet Again.” During an April 28, 2026, Senate Appropriations Committee hearing on NASA’s 2027 budget, Administrator Jared Isaacman didn’t mince words: “I am very much in the camp of ‘make Pluto a planet again.’” He revealed that NASA is already preparing scientific papers to push the scientific community to revisit the 2006 demotion.
The announcement has reignited a debate that has divided astronomers, planetary scientists, and the public since the International Astronomical Union (IAU) voted to reclassify Pluto as a “dwarf planet.” But why was Pluto demoted in the first place—and why are so many, including NASA’s leader, arguing it deserves to be called a planet again, size be damned?
Why Pluto Lost Its Planet Status
Pluto was discovered in 1930 by Clyde Tombaugh and immediately embraced as the ninth planet. For 76 years, it held that title in textbooks, classrooms, and popular culture. Everything changed at the IAU’s 2006 General Assembly in Prague. Astronomers adopted a new, formal definition of a planet to address the growing number of Kuiper Belt objects being discovered. Under the IAU criteria, a planet must:
1. Orbit the Sun.
2. Have enough mass for its gravity to pull it into a nearly round shape (hydrostatic equilibrium).
3. Clear the neighborhood around its orbit of other debris and objects.
Pluto easily meets the first two requirements—it orbits the Sun and is round enough to qualify as a dwarf planet. But it fails the third. Pluto resides in the crowded Kuiper Belt, sharing its orbital zone with thousands of other icy bodies, including some nearly as large as itself (the so-called “plutinos”). The IAU decided this meant Pluto hadn’t “cleared its neighborhood,” so it was downgraded to dwarf planet status alongside Eris, Ceres, Haumea, and Makemake.
The decision was pragmatic for astronomers trying to keep the solar system’s “planet” list manageable, but it sparked global outrage. Schoolchildren wrote angry letters. “Pluto is a planet!” bumper stickers appeared. And scientists themselves remain split.
Neil deGrasse Tyson’s Take: “Pluto Had It Coming”
Few figures have been more closely associated with Pluto’s demotion than astrophysicist Neil deGrasse Tyson. As director of the Hayden Planetarium in New York, Tyson famously removed Pluto from the planet exhibit years before the IAU vote, drawing public backlash. In his book The Pluto Files and numerous interviews, Tyson has defended the change. He argues Pluto never truly “belonged” among the major planets—its eccentric, tilted orbit crosses Neptune’s path, and it’s one of many similar objects in the Kuiper Belt.
Tyson has quipped that “Pluto had it coming” and that it’s “happier” as the king of the dwarf planets and Kuiper Belt objects. He urges the public to “get over it,” emphasizing that science refines its classifications as knowledge grows. We didn’t lose a planet, he says—we gained an entire new category of fascinating icy worlds.
Tyson’s view represents the astronomical community’s focus on orbital dynamics and the need for a clean, functional taxonomy. But not everyone agrees—especially planetary scientists who study surfaces, geology, and atmospheres rather than just orbits.
Why Pluto Is a Planet—Despite Its Size
Here’s the key point many people miss: size was never the official reason for Pluto’s demotion. The IAU definition doesn’t set a minimum diameter. Pluto is smaller than Earth’s Moon (about 1,400 miles across), but so are some accepted planetary traits in other contexts. The real issue was the “clearing the neighborhood” rule.
Critics of the IAU definition—including prominent planetary scientist Philip Metzger—argue that the third criterion is arbitrary, historically inconsistent, and rarely used in actual planetary research. No planet perfectly clears its orbit (Earth has asteroids sharing its path; Jupiter has Trojan asteroids). Metzger’s research shows the IAU’s definition would exclude objects we intuitively call planets and that planetary scientists already use “planet” to describe geologically complex, rounded bodies regardless of orbital crowding.
Pluto punches way above its weight in scientific interest. NASA’s New Horizons mission (which flew by in 2015) revealed a surprisingly active world: towering mountains of water ice, flowing glaciers of frozen nitrogen, a thin atmosphere, and possibly a subsurface ocean. It has five moons, including the massive Charon, and shows ongoing geological activity—features we associate with “real” planets. In complexity, Pluto ranks second only to Earth in our solar system, ahead of Mars.
Planetary scientists argue that a better definition focuses on what makes something a world: intrinsic properties like roundness from self-gravity, geological activity, and the ability to tell us about solar system formation—not how many neighbors it has. Under that lens, Pluto is undeniably a planet. Calling it one doesn’t require adding hundreds of Kuiper Belt objects; it simply recognizes that Pluto is a dynamic, fascinating body worthy of the title it held for most of the 20th century.
The Road Ahead
Isaacman’s comments suggest NASA isn’t just nostalgia-tripping. The agency is preparing papers to formally challenge the IAU’s stance and elevate the discussion in the broader scientific community. Whether the IAU reverses course remains uncertain—classifications like this are sticky—but the momentum is building. A child’s viral letter even helped spark recent interest, showing the issue still captures public imagination.
Pluto’s story reminds us that science is alive. Definitions evolve with discovery. Whether you side with Tyson’s orbital purism or the planetary scientists’ call for geological relevance, one thing is clear: Pluto has never stopped being extraordinary. It may soon reclaim its place among the planets—proving that even the smallest worlds can have the biggest comebacks.
What do you think—should Pluto get its planet card back? Drop your thoughts in the comments!
Sources
- USA Today: “NASA’s Jared Isaacman affirms stance that Pluto is a planet” (April 30, 2026)
- Space.com: “NASA chief Jared Isaacman says he’s fighting for Pluto” (April 29, 2026)
- Scientific American: “NASA chief Jared Isaacman hints at campaign to make Pluto a planet again” (April 29, 2026)
- Library of Congress: “Why is Pluto no longer a planet?”
- Big Think / Neil deGrasse Tyson interviews on Pluto (various, 2017 onward)
- University of Central Florida / Philip Metzger research on planet definition (2018)
