10th planet discovered (sort of)

OK. This is neither politically important nor funny. It's not even particularly scientifically important, except as it relates to elementary school text books. But I think space is cool, so I’m posting about it.

Scientists at Cal Tech claim to have discovered a 10th planet. The body, which is still unnamed, is in the Kuiper belt and about three times as far from the sun as Pluto. It’s also larger than Pluto, by perhaps 50%.

But it’s not that simple.

The discovery brings to a head the debate about whether Pluto actually deserves to be called a planet. As it turns out there are a large number of rocky planetoids similar to Pluto circling the sun beyond the orbit of Neptune called “Kuiper belt objects”, some of them substantial. Until now Pluto was thought to be the largest, so it was considered a sort of hybrid – small for a planet, large for a Kuiper belt object. But now that this new, larger-than-Pluto object has been discovered it seems inevitable that the old 9-planet definition of the Solar system is about to die. Either this new object will be added as a 10th planet or Pluto will be dropped.

Tags: space