Sedna is not that big a deal. From the point of view of physical characteristics, it is just one of many transneptunian objects discovered in the past years. Not the smallest, but not the largest either. Over time, its diameter, estimated after the discovery at an optimistic 1800 km, has dropped to half that, and today it is believed to be similar in size to Ceres, the queen of the main asteroid belt. And so, one would be forgiven for wondering-why deal with it, beyond the bare minimum of information owed to any celestial object?
