NASA has scheduled a briefing this afternoon on “the discovery of a mysterious object in our solar system,” which the BBC reports is a planet-like object provisionally known as Sedna, for the Inuit goddess of the sea (although The Australian News apparently had the scoop). Sedna is currently about 17 billion kilometers from Earth, about three times the distance to Pluto, the farthest current planet, and ranges from 1,180-2,360 kilometers in diameter, compared to Pluto’s diameter of 2,360 kilometers. As the article points out, this discovery will probably “reignite the debate over what constitutes a planet,” as some feel that even Pluto is too small to be a planet, instead classifying it as a “Kuiper Belt Object.” However, Sedna “could be the first such world discovered in its normal orbit,” unlike most of the other objects recently discovered, which apparently perturbed out of their orbits after first being observed in the Kuiper Belt region. There are some good discussions in the Slashdot and MetaFilter threads, which will no doubt become more lively once the actual press release makes the web (currently, it’s just a placeholder page).
Update: The official press release confirms that the most distant object in our Solar System has been discovered. As previously reported, the “planetoid” is called Sedna, and apparently there is “indirect evidence” of a moon that will hopefully be investigated by the Hubble Space Telescope. It looks like no one is making the bold claim that this is the 10th planet yet…
