🪐 NASA chief wants to give Pluto back its planet status

Twenty years ago, Pluto lost its planet status, a decision that still sparks debate. Today, NASA's new chief, Jared Isaacman, wants to restore its former glory. During a hearing before the U.S. Senate, he clearly expressed his support for this cause, promising to work with the scientific community to reexamine the classification.

To understand this debate, we need to go back to the rules established in 2006 by the International Astronomical Union (IAU). Three criteria were set: orbit the Sun, have sufficient mass to assume a spherical shape, and have cleared its orbit of debris. Pluto meets the first two, but not the third, because it shares its zone with other Kuiper belt objects. However, opponents note that Earth and Jupiter also coexist with asteroids, calling the consistency of this rule into question.


Jared Isaacman, a billionaire entrepreneur and private astronaut, became NASA's administrator in December 2025. Questioned by Senator Jerry Moran, he stated that he belongs to the "make Pluto a planet again" camp. He added that his team is preparing documents to restart the debate within the scientific community, in order to give American Clyde Tombaugh, Pluto's discoverer, the recognition he deserves, in his view.

However, the decision-making power lies with the IAU, a worldwide organization of professional astronomers. NASA can only encourage discussion without imposing a change. Jared Isaacman acknowledged this, saying he wants to "escalate" the issue with scientists. The IAU remains the sole judge in redefining what a planet is.

In July 2015, NASA's New Horizons probe flew by Pluto for the first time, revealing a surprisingly diverse world with mountains and nitrogen glaciers. Despite these spectacular images, the IAU has not revisited its decision. It remains to be seen whether the NASA chief's public commitment can tip the scales this time. The debate remains open, and supporters of reinstatement hope that new evidence will manage to convince the IAU.

The Kuiper belt: a reservoir of icy worlds

This vast region of the Solar System, located beyond Neptune's orbit, extends from 30 to 50 astronomical units from the Sun. It contains billions of icy objects, including comets, asteroids, and dwarf planets like Pluto. Discovered in the 1990s, the Kuiper belt has transformed our understanding of the outer Solar System. It is estimated to contain more than 100,000 objects over 62 miles (100 km) in diameter. Pluto is its most famous representative, but other worlds like Eris, Haumea, and Makemake also reside there, considered remnants of the Solar System's formation.

The presence of numerous planetary-sized objects led the IAU to define the category of "dwarf planets", distinct from "planets", of which Pluto is the prototype. Exploration by New Horizons in 2015 showed that Pluto has active geology, with nitrogen glaciers and possibly an underground ocean. These discoveries reinforce the idea that the distinction between planet and dwarf planet remains a debated subject.