Small Dark Spot

The Small Dark Spot was found at a latitude of 54° South while rotating East around Neptune with a period of 16.1 hours.

[4] The dark oval of this storm which created the overall outline for the eye-like shape was formed by a clockwise rotating vortex which sucked atmosphere inward toward the planet center.

[5] This action of pulling atmosphere downward created a hole in the upper methane cloud deck of Neptune and gave the storm its darker blue tone.

[7] Also present within the dark region of the storm were sharp band-lines potentially indicating unseen high winds, despite exact measurements having never been taken.

[5] The bright central region representing the pupil of the eye-like shape was formed by white methane-ice clouds upwelling from the center of the storm.

Great Dark Spot (top), Scooter (middle white cloud), and Small Dark Spot (bottom).
A high-resolution view of the Small Dark Spot
True color NASA image of Neptune
True color NASA image of Neptune