Ixion is a plutino (an object that has a 2:3 orbital resonance with Neptune) and a very likely dwarf planet; its diameter of 650 km estimated by Spitzer makes it about the fifth largest plutino.
Ixion is a plutino (an object). Ixion is a very likely dwarf planet. This object has a 2:3 orbital resonance with Neptune. Its diameter of 650 km makes it about the fifth largest plutino. This 650 km is estimated by Spitzer.