re: #400 jaunte

This kind of makes me happy. Many years ago I went to the Lowell Observatory in Flagstaff and sat at the machine Tombaugh used to discover Pluto. It was a blink comparator. Basically, Tombaugh was up all night taking pictures of the night sky where it was thought Pluto was lurking. Then he’d develop the negatives after sunrise and put them on this machine, which would switch back and forth between the two negatives. Since planets move much faster than the background stars, if something was moving against the stars, you’d see it move from night to night. And that’s how Tombaugh discovered Pluto in 1930.

The Lowell blink comparator went to the Air & Space Museum three years ago for a three year stay, but may be back in Flagstaff by now. Here’s a story.

airandspace.si.edu

And this is why I think Pluto is a planet. Clyde Tombaugh worked HARD to find Pluto, taking pictures night after night, squinting at plates day after day. Just My Personal Opinion.