It amazes me that, with all the neat things we can see with telescopes looking out far away into the galaxy, we still don’t have a great handle on what’s closer to home.
The short version of this interesting story on PhysOrg is that folks at the Universities of Madrid and Cambridge have done the observations and the math, and conclude that, because of the way many objects out past Neptune are acting, they think it’s very likely there are up to two more planets hiding out there, very cold and very dark. It’s those last two issues that makes it so hard to see them, if they are indeed there. With some people *still* smarting over the whole “Pluto is a dwarf-planet” thing, I can’t wait to see heads asplode if we need to add a few more full-sized planets to the list.
On the other hand, if there are more planets out there, what should we name them?