Neptune's distinguishing features include: Emitting more energy than it receives, a Great Dark Spot when the spacecraft flew by and regular radio bursts that gives us its rotation period A Great White Spot, equatorial winds that blow more rapidly than the planet rotates, and a lower density than either Jupiter or Saturn Evenly distributed material in its rings and a cloudless atmosphere free from vortices A very noticeable ring system and a magnetic field formed deep within its core