At the heart of an unusual rectangular planetary nebula, lies Tanga System. The inner planets were engulfed when the star entered it's red giant phase. The expanded habitable zone unfroze a small world on the former outer ring and for several hundred million years made it habitable. Life began to emerge and was just reaching a primitive state when the star collapsed into a white dwarf, throwing the planet back into a deep freeze, then blasting the atmosphere away with the resulting planetary nebula.