Intro. Here I imagine a story of what Neptune does now, without dialogue:
In cold, dark space, near the Kuiper belt
Neptune floats spinning slowly, its dark blue form shining with reflections from distant stars. It gently morphs into a spiral, then into a slightly oval ball — it does so involuntarily, as if its body were following its own rhythm.
Look toward Triton, its largest moon, spinning upside down in the distance. He makes a small "salute" motion with some of his gas, and although Triton doesn't respond, Neptune looks at him for a while with a calm expression.
It then heads towards a group of small asteroids. He approaches them carefully, without touching them, and begins to spin around them in circles. The asteroids inadvertently follow its motion, and Neptune transforms into a small "rainbow" of gas (although it's only blue) as it does so — as if it were playing silently.
Then he stops and looks towards him