Ashes of Pluto discoverer on board New Horizons for historic flyby

When NASA’s New Horizons completes its historic flyby of Pluto later today, the man who first discovered the now-dwarf planet in 1930 will be there in more than just spirit, as a small amount of the late astronomer’s ashes have made the journey along with the spacecraft.

According to, American astronomer Clyde Tombaugh discovered Pluto 85 years ago when he was just 24 years of age. The Kansas native had been working at Lowell Observatory in Flagstaff, Arizona, helping astronomers search for a planet located beyond Neptune by reviewing millions of images, New Horizons team members at Johns Hopkins University said.

Tombaugh’s search for a “trans-Neptunian” world came to an end in February 1930, when he caught his first glimpse at what would later be named Pluto. Initially believed to be a planetary oddity because of its small size and unusual elliptical orbit, his work eventually led to the discovery of the Kuiper Belt and the realization that small, icy dwarf planets were common in the Milky Way.

Tombaugh, who died on January 17, 1997 at the age of 90, was the first American to ever find a new planet in the solar system. To honor him, a small aluminum canister containing some of his ashes (donated by his family) was placed on board New Horizons. He is the first man to have his remains launched into interstellar space, according to the mission team.

Posthumously visiting the planet he discovered

The canister containing his ashes is approximately two inches wide and one-half inch tall, and was attached to the inside of the piano-sized spacecraft’s upper deck, according to CNN. It also bears an inscription written by Dr. Alan Stern, the head of the New Horizons mission.

The inscription reads: “Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system’s ‘third zone.’ Adelle and Muron’s boy, Patricia’s husband, Annette and Alden’s father, astronomer, teacher, punster, and friend: Clyde W. Tombaugh (1906-1997).”

On Tuesday, as New Horizons travels to within 7,800 miles (12,500 kilometers) from the surface of the dwarf planet and becomes the first spacecraft to complete a flyby of Pluto, the man who discovered the icy world will be along for the ride – and his family couldn’t be happier about it.

“When he looked at Pluto, it was just a speck of light,” Tombaugh’s daughter Annette said earlier this year, according to CNN. “To actually see the planet that he had discovered and find out more about its atmosphere, find out more of what it is and actually get to see the moons of Pluto, he would have been astounded.”

Likewise, back in 2006, his wife Patricia called the gesture “a wonderful tribute.”

“Clyde Tombaugh was a grand American, and New Horizons is a grand American adventure,” Dr. Stern added at the time. He called Tombaugh’s work “a contribution to planetary science that we now know heralded a paradigm shift in our understanding of the geography of our home solar system” and added that it was an “honor… to have launched some of his remains… on the historic mission of exploration that is New Horizons.”