All the ink and pixels spent in recent years on the question of whether Pluto ought or ought not be considered a planet missed the most interesting development in the story of this distant rock (or whatever it is.) Astronomer Mike Brown of the California Institute of Technology puts it this way:

“You’re looking at the surface in the solar system where there are the biggest changes we’ve ever seen,” Brown said.

The color of the surface of Pluto changed so markedly, particularly between 2000 and 2002, that Buie has spent years checking and rechecking his work, just to make sure the differences weren’t an artifact of faulty equipment or calculations.

“I got that result years ago but it’s just so hard to understand and believe that I’ve been checking everything that I can think of,” he said. “I’m still nervous about it. It could be that I’ve just completely screwed this up, but I can’t find where.”

Until someone can provide a plausible reason why a planet (dwarf or otherwise) would just up and change color like that, I have to lean in the "he screwed up" direction.

But it's intriguing...

Check out this composite video of Pluto rotating.

This apparently shows Pluto post-color-change. I wonder what it looked like before?