Earth, or Gaia or Terra as it is known elsewhere, is the third planet in the Sol System and the homeworld of humanity, plus the first natural known E-Class world to humans. Earth has one natural satellite, Luna and it is the nominal center of the Confederacy of Humanity.
As of 100000 Earth has undergone major upheavals, but is currently a paradise like it was at the start of the Fourth Age. Many green megacities can be seen from orbit spread across the planet, a few even in the ocean. Most farming on Earth is accomplished via either massive farming towers built in placed where there could be no cities before (e.g. Sahara Desert) or large floating farms on the oceans, but there are still some foodstuffs imported from other colonies.
The Earth is greener than it was back in the 21st century thanks to the population crash and subsequent ruralization of most of the large cities on Earth. Each building and home of each terrestrial city and megacity now is required to have small plants and/or grass growing on their roofs as well as in their lawns. There were even a few cities, such as Detroit, Michigan and Dhaka, Bangladesh were completely abandoned and taken down in order to let nature reclaim the land. Those cities had since been rebuilt greener.
Most of the energy on Earth comes from a mixture of solar energy, fusion energy, wind energy, hydroelectric energy and geothermal energy as well as a few others.
Being the homeworld of humanity the global population of 26.1 billion makes Earth the largest populated body in the entire system, and that doesn't include the large amount of habitats and space elevator cities in orbit. Most of the population live in the megacities, but some still live in parts of reclaimed nature. Earth is the most diverse world culturally.
Earth has one of the most diverse climates in the entire system. Cold enough at the poles to freeze water and warm enough at the equator to fry an egg on a metallic surface, each region of Earth has a unique biosphere able to support a variety of plant and animal life.
Earth never had any rings until the year 13728 CE. In celebration of Vega becoming Earth's new North Star, a petition went through the terrestrial government, pleading for a beautification type project, as Solarians (which is what all inhabitants of the Sol System called themselves at the time) were obsessed with physical beauty. Many of asteroids and comets were diverted and crashed into each other. A few smaller asteroids were placed in orbit in order to keep the rings from degrading and trillions of nanites were released to construct the rings. The nanites then rained down after completing their tasks, forming the most brilliant meteor shower seen on Earth in millenia. They have since remained stable.