Sounds like a pair of scenes ripped from your standard off-world fantasy novel, except the science behind these alien planets isn't fiction. Aurelia and Blue Moon are based on computer models created by NASA and SETI Project researchers to help identify which stars among the universe's 70 sextillion are most likely to support life. CGI representations of the worlds first appeared in a National Geographic documentary; the film and related interactive simulations are on display through February at the London Science Museum. A US tour is planned for this fall.

Scientists began with the essential ingredient for life: They assumed both worlds in the exhibit contained water. They then used as blueprints two scenarios formulated by the SETI Project. The first is a planet orbiting a sun close enough to keep water from freezing out, yet far enough away to avoid evaporation. The other is a moon orbiting a gas giant and warmed by twin suns.

To make the worlds as realistic as possible, SETI astrophysicist Laurance Doyle and NASA researcher Manoj Joshi ran detailed climate simulations on a desktop Linux box. The sims allowed the scientists to observe the consequences on habitability of a range of complex atmospheric variables like thermal circulation and precipitation levels. Next, a group of life scientists, led by University of Cambridge paleobiologist Simon Conway Morris, applied the principles of natural selection and adaptation to populate the planets. They determined creature leg lengths and wingspans using biomechanics algorithms, and they established vegetation height and characteristics according to factors like available light and the amount of carbon dioxide in the atmosphere.

"Implicit in these biospheres is the concept of evolution," says Conway Morris. As a result, the inhabitants of Aurelia and Blue Moon look more like something that might be encountered on the Galapagos Islands than at the cineplex. The life-forms on these pages illustrate realistic adaptations to an environment. Adaptations that almost - but not quite - befit creatures right here at home.

Vernor Vinge, a computer scientist and science-fiction writer who’s now a professor emeritus at San Diego State University. We're living through a period of unprecedented technological and scientific advances, Vinge says, and sometime soon the convergence of fields such as artificial intelligence and biotechnology will push humanity past a tipping point, ushering in a period of wrenching change. After that moment -- the Singularity -- the world will be as different from today,s world as this one is from the Stone Age.