News traveled fast.  The day after Vesto Slipher made his announcement of Clyde Tombaugh’s discovery, papers around the world ran front-page headlines calling the “trans-Neptunian object” a “planet”.   Notice that while the cautious astronomers at Lowell Observatory hadn’t declared the object a planet themselves, the public did it for them.

You have to think Slipher knew this would be the case.  After all, finding a planet solved all kinds of problems for the observatory staff — most of all, the problems of expectation.  The Lowells, including Percival Lowell’s widow Constance, were keen to end the search with a success story.  They’d poured plenty of money, and a lot of heartache, into the project.

How terrible if Lowell had spent all those years just chasing ghosts.

(They don’t write them like this any longer, do they?)

These early reports are typically breathless.  Observations in the next few weeks would bear out Planet X’s apparently small size.  Rather than being 1200 times the size of Earth, Pluto is smaller than Earth’s moon.