Mirica

Mirica is the name of the planet upon which Daniel Oglethorpe and Elizabeth Oglethorpe found themselves cast after the Watcher's ship collided with their airplane. It was populated by the mysterious Others with humans and also Neanderthals.

Geography
The planet Mirica had no moon, but had as many as twelve stars that outshone the scores of lesser suns in the star cluster that the planet was located in. It orbited a G0-type sun and from one hemisphere, seven of the brightest blue giant stars shone. According to Daniel Oglethorpe he believed that Mirica laid on the edge of a large cluster looking outward or a small cluster looking inward though this was only speculation. The planet also has lighter gravity than Earth.

Fifty percent of Mirica is comprised of landmasses. Plateaus separated by chasms ten thousand feet deep. The planet's terrain contained great chasms that cut to ten thousand feet or deeper that separated plateaus hundreds to thousands of miles across. These plateaus contained mountain ranges twenty thousand feet high. Mirica contained a complex biosphere at the tops of the mountains to the bottom of the chasms.

Organisms in theses biospheres had adapted to oxygen levels ranging from 30 to 10 percent, respectively, a contrast to Earth’s 21 percent at sea level. At 30 percent oxygen, there was a danger of increased fire potential, while the oppressive humidity existed near the chasm depths and the seas.

Source

 * Ancient Enemy by Olan Thorenson