A circle of darkness obscures the starfield beyond. It moves slowly and silently through the cold reaches of deep space. As it approaches, a hint of light can be seen glittering from its surface, then suddenly it coalesces into the shape of a planet. Alone, far from the system that gave birth to it, the planet wanders between the stars. The surface has cooled long ago, but beneath that surface the heat from the center of the world provides a dwindling source of energy.
Researchers predict that nomad planets, which do not orbit any star, are far more common than previously thought. They can be ejected from their original systems for a variety of reasons, including the most spectacular celestial event, a super nova. If models are correct, then these planets far-outnumber the stars in the sky. Read an article here: http://news.nationalgeographic.com/news/2012/02/120224-rogue-nomad-planets-stars-black-holes-space-science/