I think it's a neat idea but probably needs more contributors and for people to be a bit more critical with things. For example, an obvious one, I don't see it mention that Pluto is no longer classified as a planet. That would be a great thing to mention, especially if you talk about things we used to consider planets but don't any longer. Ceres is another example of this. In 1801 it was discovered and considered a planet until sometime in the 1950s (it seems like it wasn't an all-at-once shift) when it was considered an asteroid despite its planet like appearance. Now it is considered a dwarf planet like Pluto.