Eris and Pluto
Oct. 27th, 2011 10:34 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
steorra posting in ![[community profile]](https://www.dreamwidth.org/img/silk/identity/community.png){kind=small}
astronomyMike Brown on the sizes of Eris and Pluto, and why the discovery that Eris is almost exactly the same diameter as Pluto actually tells us that Eris is more different from Pluto than expected.
Basically: We know Eris is a bit more massive than Pluto, so if it also had a bit bigger diameter than Pluto, it could have the same density, and therefore be made more or less of the same stuff. But since it's the same diameter, it must be denser, and therefore made of different stuff.
Basically: We know Eris is a bit more massive than Pluto, so if it also had a bit bigger diameter than Pluto, it could have the same density, and therefore be made more or less of the same stuff. But since it's the same diameter, it must be denser, and therefore made of different stuff.
