Earth has been long abandoned due to its toxic atmosphere. It is now overgrown with mutated jungle structures that have devoured most of the prior signs of civilization. Infestation and roaming wildlife still inhabit its surface but anything of value was stripped by scavengers generations ago.
Earth (also referred to as Ancient Er by the Ostron people) is a planet under Grineer control, and is the first planet players can access. It is linked through junctions to Mars and Venus. Lua, the Earth's moon, becomes accessible from Earth (without a junction) after players complete the quest The Second Dream.
The Assassination Target for Earth is Councilor Vay Hek, located in the mission node Oro, though unique to Earth, his node is not able to be accessed (or required to be defeated) until the player has progressed way further into the solar system. Vay Hek drops the component blueprints and parts of the HydroidWarframe. A Mastery Rank of 5 or higher is required to access the mission node.
Earth is the only planet to feature the Grineer ForestTileset. Every four hours, the forest tileset will change from day to night, mimicking the day cycles in real life. The change will feature different vegetation that can be scanned for extracts that are used to craft Antitoxins, Apothics and medical regeneration packs, with Sunlight variants during the day and Moonlight variants at night.
Various geological events and formations pertaining to Earth (Lith, Cambria, Mantle).
The personification of the Earth in Greek Mythology (Gaia).
Despite being previously described as a "desolate, ruined world" Earth has very lush forests, which Vay Hek tried to destroy during The Cicero Crisis. This original description is probably no longer canon.