2004 XR190

First observed in December of 2004, 2004-XR190 is a newly discovered Kuiper Belt Object (KBO) that is just plain weird. It lies way out there, around 52-62 AU from the Sun -- but has what appears to be a complete circular orbit with a 47-degree inclination from solar plane. This means that it spends only 2% of its orbit in the solar plane, where most surveys for KBOs are done. Ideas have been dropped to explain the large eccentricity of the orbit, but none that are sticking.