Sunday, June 17, 2007
All Hail Eris, Queen of the Dwarf planets
Remember Eris? The icy worldlet that was bigger than Pluto? The one, that when it was proposed that it become the 10th planet an astronomical brouhaha resulted with Pluto demoted to being a Dwarf Planet? Well, it now turns out that Eris is heavier than Pluto as well. By observing the orbit of Eris's moon Dysnomia, Mike Brown and his team were able to determine the mass of Eris. It turns out to be around 27% heavier, than Pluto, which suggests that Eris and Pluto are of similar composition, mostly ice with some rock thrown in. You can read more about this at Science, Nature, New Scientist, ABC science Online and Centauri Dreams.