A planet whose orbit is a little stretched dives closer to its star each pass, then backs away. The varying gravity heats it up, solid rocks melt, becoming an ocean of lava.

On the night side, a frozen crust acts as a shore. Tidal waves crash against it, collide, and spawn wandering hot spots. As a result, the planet’s glow flickers erratically, like a candle flame. Waves can rise several kilometers high — slow-moving stone ridges crawling across the scorching expanse.