Aristo was a planet most notable for being the hiding place of Ensor for many years. Its position is unknown but it was, according to Ensor's son, six days from Cephlon. Aristo had a breathable atmosphere but was 90% covered by acidic seas. The land was arid but supported primitive plant life. At the time of the Liberator crew's visit the sea levels were slowly rising. The most notable native life form was the Phibians, aggressive semi-humanoid creatures with reptilian characteristics.