The Great Spiral
Ominously somewhere in an empty spot in space floats a sphere of gray liquid no less than the size of a red dwarf. Alone, this ball of gelatinous ooze is an anomaly in the night sky, invisible to the naked eye and thermal detection; it’s origins and nature is a mystery to all who encounter it, and woe to the unsuspecting traveler who doth stumble across the Gray Goo.
The Gray Goo is actually a colony of synthetic nanomachines designed by an unknown sentient race to consume carbon and to replicate itself. It originated on an earth-like planet where self replicating nano bots were deployed to attack and clean oil spills, but due to a programming error, they devour all carbon based objects, instead of just the hydrocarbons of oil. Within ten hours after the Goo’s release into the ocean, the oil spill was compleatly consumed, as was the cleaning crew and all sea life within 25 miles. After a day it had eaten its way to nearly ever coast and consuming the very ground upon the Goo’s creators stood. After two days the very planet crumbled to dust, all it’s minerals depleted. Eventually the Gray Goo had devoured all planets in the system and siphoned the energy of its own sun. Now it makes for other systems, moving slowly and silently through space.
Each individual nano bot is nearly a perfect engine, loosing close enough no energy to operate, thus having a lifespan of at least several million years. This makes it impossible to know how old the Gray Goo is, and why the star sized mass does not appear on thermal or infrared scanners. The nano bots have the most basic of intelligence, able only to identify potential sources of energy. Even so, their Parallel computing network allows for superior mathematical problem solving, out processing the fastest of supercomputers.