In 2015, eighty-five years after its discovery, Pluto finally received its first visitor. The New Horizons mission was more than a scientific reconnaissance; it was a deeply poetic closing of the circle for Clyde Tombaugh’s life story. Though Clyde passed away in 1997, he was physically present for the historic encounter—becoming the first human being to have their remains sent to the world they discovered, and eventually, the first to leave our solar system entirely.
The Ultimate Passenger
When New Horizons launched in 2006, it carried a small aluminum canister attached to the inside of its upper deck. Inside was one ounce of Clyde Tombaugh’s ashes. The container bears an inscription that captures the essence of the man:
“Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system’s ‘third zone’… Ad Astra per Aspera (To the stars through difficulties).”
This gesture transformed the mission from a cold calculation of data into a memorial flight. As the spacecraft sped toward the Kuiper Belt at over 30,000 miles per hour, it carried the very person who had first identified that faint, flickering dot on a glass plate in 1930.
The “Heart” of the Mission
When the spacecraft made its closest approach on July 14, 2015, the most striking feature it revealed was a massive, bright, heart-shaped glacier. The New Horizons team immediately and informally named this feature Tombaugh Regio (Tombaugh Region).
The “Heart” turned out to be one of the most geologically fascinating places in the solar system:
- Sputnik Planitia: The western lobe of the heart is a vast plain of nitrogen and carbon monoxide ice.
- Geological Youth: Surprisingly, this region is virtually craterless, suggesting that Pluto is still geologically active—”breathing” and resurfacing itself even today.
- Atmospheric Engine: Scientists discovered that the nitrogen ice in Tombaugh Regio actually drives Pluto’s weather, circulating winds across the entire planet.
Beyond the Ninth Planet
New Horizons did not stop at Pluto. After the flyby, the craft continued deeper into the Kuiper Belt, a region Tombaugh had long suspected was filled with thousands of icy bodies. In 2019, it visited Arrokoth, a “space snowman” that provided clues about how planets first formed.
Clyde Tombaugh’s legacy is now literally written in the stars. As New Horizons continues its journey into interstellar space, Clyde remains the ultimate explorer, heading into the infinite dark he spent his life trying to illuminate.
Clyde Tombaugh 