Not a "structure", but rather atmospheric resonance create this polygonal shape, from cyclones self-arrangement etc.

Same thing on Jupiter, by the way, known since a long time.

I'd say that "structure" is click-baity, as it evokes some artifact.

Given the well-known hexagon on its north pole this decagon doesn't seem that surprising after all.

Perhaps “feature” would be most appropriate.

But then the title would be less clickbait.

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