By: Marc J. Kuchner
Eighty-seven years ago, this week, Clyde Tombaugh was poring over a pair of photographic plates, hoping to change the world. He was staring hard into an arcane device called a blink comparator, which allowed him to rapidly switch from viewing one image to the next. In those days before computers, that was the best tool he had for finding the faint, moving dot he was seeking, a new planet in our solar system.
When Tombaugh discovered Pluto in those photographic plates o