Another one!

Astronomers have found another “dwarf” planet deep in the solar system. It’s temporarily been designated 2015RR245, which isn’t a very exciting name, but presumably they’ll give it an official name soon.

Here’s a cool diagram showing the currently-known distant planets:


Everyone knows Pluto, and many years ago when I taught science class, I talked about Sedna, Makemake, Haumea, Quaoar, and Eris. But now I see we’ve added Varuna, Varda, Ixion, and a handful of other yet-to-be-named guys. I’m not sure if someone has yet come up with a song or mnemonic (remember “My very fine mother just served us nine pizzas”?)…

It’s exciting that our local neighborhood is much busier and more complicated than we’ve imagined!