NASA chief Jared Isaacman, the billionaire entrepreneur and former astronaut, is once again pushing for a planetary promotion.

Isaacman’s focus revolves around the far-off icy world of Pluto, first identified in 1930 by Clyde Tombaugh at Lowell Observatory, and long taught as the solar system’s ninth planet.

That categorization changed in 2006, when the International Astronomical Union (IAU) controversially voted to reclassify Pluto as a dwarf planet—a move that has faced ongoing backlash.

At the center of the dispute is the IAU’s definition of a planet. To achieve planethood, a celestial body must orbit the Sun, be nearly round and have the gravitational influence to clear its orbital neighborhood of debris.

Pluto meets the first two but falls short on the third. Measuring about 1,400 miles wide, roughly the size of Australia, Pluto isn’t big enough to gravitationally dominate its orbit and clear it from smaller chunks of space rock.

As a result, the frozen world tucked beyond Neptune was reassigned to a new category.

Isaacman, who has repeatedly maintained — in the Daily Mail and on the social media platform X — that Pluto deserves full planetary status, recently reaffirmed his stance. His latest remarks came as he spoke April 28 before a U.S. Senate committee on President Donald Trump‘s significant cuts to NASA’s proposed budget.

According to USA Today, after more than an hour of testimony, the NASA chief was asked about Pluto by Sen. Jerry Moran, R-Kansas, who chairs the Senate Committee on Appropriations.

Isaacman replied, “Senator, I am very much in the camp of ‘make Pluto a planet again.’” He then alluded to a number of research papers in the works at NASA that “we would love to escalate through the scientific community to revisit this discussion.”

Isaacman’s perspective aligns with a broader camp of scientists and enthusiasts who say the IAU criteria are too restrictive, especially given Pluto’s complex geology, glaciers and moons revealed by NASA’s New Horizons flyby in 2015.

Support for Pluto’s reinstatement isn’t limited to NASA leadership. Scientists like Alan Stern, who led the New Horizons mission, have long advocated for a broader definition of planets. Stern believes planethood should be based on geophysical criteria rather than orbital dynamics.

Even public figures — from William Shatner to Elon Musk — have weighed in, reflecting how a technical classification has evolved into a cultural debate.

In a 2025 post on X, Shatner quipped, “We should ask Elon to get the President to sign one of those Executive thingies to make Pluto a planet again.”

Musk replied, “Yes! Pluto is the 9th planet!”

Declaring Pluto a planet again through an executive order would carry no scientific authority. Any official reclassification would have to come from the IAU, which remains the governing body responsible for defining planetary status.

NASA局长贾里德·艾萨克曼，这位亿万富豪企业家兼前宇航员，再次发声推动为冥王星“行星正名”。

艾萨克曼的关注点聚焦于遥远的冰冷世界——冥王星。它于1930年由克莱德·汤博在洛厄尔天文台首次发现，长期被当作太阳系第九大行星。

这一分类在2006年发生改变。当年，国际天文学联合会（IAU）颇具争议地投票将冥王星重新归类为矮行星，此举一直面临反对声音。

争议核心在于IAU对行星的定义。要成为行星，天体必须绕太阳公转、近乎球形，并且具有足够的引力清除其轨道附近的碎片。

冥王星满足前两条，但第三条不达标。其直径约1400英里（约2253公里），与澳大利亚大小相仿，引力不足以清除轨道周边的小天体。

因此，这颗位于海王星之外的冰冻世界被重新归类。

艾萨克曼多次在《每日邮报》和社交平台X上表示，冥王星理应享有完整行星地位。他最近再次重申这一立场，时间是在4月28日向美国参议院委员会就特朗普总统大幅削减NASA预算提案作证时。

据《今日美国》报道，作证一个多小时后，堪萨斯州共和党参议员、参议院拨款委员会主席杰里·莫兰向NASA局长问及冥王星。

艾萨克曼回答：“参议员，我坚定支持‘让冥王星再次成为行星’。”他随后提到，NASA有多篇研究论文正在推进，“我们很乐意通过科学界推动重新讨论此事”。

艾萨克曼的观点与一大批科学家和爱好者的立场一致。他们认为IAU的标准过于严苛，尤其是2015年NASA新视野号探测器飞越冥王星后，揭示了其复杂的地质、冰川和卫星。

支持冥王星恢复行星地位的不限于NASA领导层。新视野号任务首席科学家艾伦·斯特恩等长期主张采用更宽泛的行星定义，认为应基于地球物理标准而非轨道动力学。

甚至公众人物 —— 从威廉·夏特纳到埃隆·马斯克 —— 也参与讨论，反映出一项技术分类已演变为文化辩论。

夏特纳2025年在X上打趣：“我们应该请埃隆让总统签个行政令，让冥王星再度成为行星。”马斯克回复：“没错！冥王星是第九大行星！”

通过行政令宣布冥王星再次成为行星没有科学权威性。任何官方重新分类都必须来自IAU，它仍是负责定义行星地位的权威机构。

(Translated by DeepSeek)