Erth

Erth is a fictional terrestrial planet that appears in science fiction literature and media. The name is a deliberate variant of Earth, used to evoke familiarity while signaling an alternate world.

In common depictions, Erth orbits a sun-like star and hosts life broadly similar to that of Earth. Many authors assign Earth-like gravity and atmosphere, though some alter axial tilt, climate, or biosphere to create unusual environments. The surface is described as diverse, with oceans covering a substantial fraction of the planet and continents arranged in configurations that differ from Earth. Some narratives emphasize extreme climates, while others present temperate, hospitable realms.

Geography and ecology are varied across works. Some versions feature stable, life-supporting ecosystems, while others explore desolate or rapidly changing landscapes. Geological activity, weather patterns, and biomes are often used to reflect themes such as environmental stewardship or resilience in the face of change.

Civilizations on Erth range from prehistoric cultures to technologically advanced societies. Political structures vary widely, including democratic states, regional federations, or planetary governance in far-future settings. Interactions with other species or human settlements—when present—drive plots centered on exploration, diplomacy, and cultural exchange. Economic systems and technology levels span a wide spectrum, from agrarian economies to spacefaring civilizations.

Because Erth lacks a single canonical setting, its depiction is fluid and context-dependent. Authors use the world to explore familiar human themes in speculative contexts, such as resource conflict, social upheaval, and the ethics of exploration and colonization.

See also: Earth; Planets in fiction; Exoplanets in fiction.