Clyde William Tombaugh was born in Streator, Illinois on February 4, 1906 into a farming family. Though accepted to college at sixteen, a hailstorm ruined his family's crops, and he remained to work on the farm.
At age twenty he began constructing telescopes for his own use. To provide an environment with constant temperature and without currents of air to disturb the images, he excavated more than 1,300 cubic feet (almost 40 cubic meters) of dirt, using just a pick and shovel, to form a trench 24 feet (7 meters) long. He observed Mars and Jupiter through his telescopes, drew what he saw, and mailed the drawings to the Lowell Observatory in Flagstaff, Arizona. The observatory sent back a job offer, which he accepted.
A year later, Tombaugh discovered the body Pluto, the first object identified in the Kuiper belt. Pluto was immediately designated a planet.
Tombaugh earned a bachelor's and a master's in astronomy at the University of Kansas. He worked in the defense industry during World War II and into the mid-1950s, when he moved to academia. He taught astronomy at New Mexico State University until his retirement in 1973. He died in 1997, aged 90, survived by his wife of 63 years.
Inspired in part by the 1991 release of the USPS "Pluto: Not Yet Explored" stamp, NASA began planning an observation mission. In 1992, Robert Staehle of JPL called Tombaugh to ask permission to visit "his planet". The mission was delayed due to budget cuts, but fourteen years later — in 2006 — the New Horizons space probe had been completed, and it was launched on a nine-year course to visit Pluto. On July 14, 2015 — eighteen years after Tombaugh's death — New Horizons flew past Pluto and sent pictures back to Earth and a crowd of cheering researchers.
Following a ruling by the International Astronomical Union in 2006, while New Horizons was en route, Pluto lost its status as a planet. But while Pluto may now be designated a "dwarf planet", Tombaugh remains a giant in the history of astronomy.
For these covers, I processed a 1930 photograph of Tombaugh with his homemade 9-inch telescope, giving it a flare and a vignette with the feel of an heirloom photographic print. The text "Clyde W. Tombaugh: Discoverer of Pluto, 1906 - 1997" is printed along the bottom, and the text and photo sit atop a field of blue star flares. I used one Pluto stamp (Scott #5077) from the 2016 "Pluto Explored!" issue for postage, cancelled with a beautiful pictorial postmark — depicting Tombaugh himself, a reproduction of his signature, and a telescope — from his hometown of Streator, Illinois, dated July 9, 2016.