NASA's New Horizons probe flew past Pluto earlier this week, sending back to Earth spectacularly detailed images of the one-time planet. The voyage was bittersweet for many who believe Pluto should have remained in our solar system, but the journey also held symbolic value for the offspring of astronomer Clyde Tombaugh, who discovered Pluto in 1930. Tombaugh's ashes were aboard New Horizons, stashed in a two inch by one and a half inch canister, prime real estate in the "piano-sized" space of the probe. 

"When he looked at Pluto, it was just a speck of light," said Annette Tombaugh, his daughter. "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."

The canister is embossed with an inscription, from Alan Stern, the head of the New Horizons mission, in case any future aliens are interested in its contents. It 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)."

Cover: NASA