What Astronomers Thought Pluto Looked Like Before They Saw It Up Close
It's been 91 years since amateur astronomer Clyde Tombaugh first spotted Pluto on a set of glass negatives. Since then, the object has been declared a planet, named, and, of course, demoted to a dwarf planet in 2006. Whatever its status, our fascination with Pluto has held fast. But until very recently, we didn't have...