Aphras

Description
A unique discovery, Aphras is a "heavenly twin" - a planet in a star system that has not one but two worlds of sufficient size to retain a nitrogen-oxygen atmosphere within the habitable life zone of its parent star. Fossil evidence shows abundant vertebrates and evidence of a sapient terrestrial avian species in its Bronze Age. However, the only trace of contemporary life on the planet is that of single-celled organisms in its seas. All else has suffered from an extinction event - a series of massive impacts that vaporized vast quantities of water and lofted dust into its atmosphere. Early theories that this event was a collision with a fragmenting asteroid have now been discounted - the impact craters were aimed directly at habitation centers.