Evolution

The sky hadn't always been blue: it used to be all the colours in a supernova, saturating everything in rainbow radiance as far as you could see.

Then came that strange entity, an oblong proto-moon moving purposefully towards the peaceful planet. Comets came and went in their huge elliptical orbits, describing slow moving trails across the dark sky on the rare occasions the triple suns were setting and sunsets of every hue illuminated the horizon. But this visitor was leaden, metallic and threatening.

There was the belief that matter changed and entropy would eventually render all things to the same boring level, and this monstrous interloper might have been its agent.

But this was not boring. It was dreadful... and blue. Not the blue of many skies lit by yellow suns, nor the chill hue of ice.

Long before its oppressive shadow fell over the planet, it was obvious that the threatening entity was no regular space debris. It was the size of several moons and held a precise position as it blocked the yellow sun's rays so its malign presence merged with the small blue star's. Despite being a red giant, the largest sun's corona was not strong enough to counteract it.

Signs of life were detected in the sinister visitor. Odd signals, incoherent and random, merged with the background transmissions of its smaller target world.

Long ago, the ancestors of the planet's inhabitants had discovered this lush, illuminated world and made it their own. The fact that an intelligent species already prospered on it did not trouble them. Technologically advanced and unable to comprehend the lives of more lowly (i.e. less technological) beings they exterminated the original population.

Under its new regime the planet blossomed into a flourishing, peace loving paradise. There was no need for envy here.

It was inevitable that this cosmic gem would attract the jealous attention of a species more technologically advanced and unable to understand the lives of its more lowly (less technological) population.