Greti

This is a list of Foundation universe planets featured or mentioned in the Robot series, Empire series, and Foundation series created by Isaac Asimov.

The star system 61 Cygni, in the Sirius Sector, is advanced by Lord Dorwin as the potential site for a planet of origin for the human species. Lord Dorwin cites '' (meaning Earth's Sun) and three other planetary systems in the Sirius Sector, along with Arcturus in the Arcturus Sector, as potential original worlds. (This fact seems to be contradicted by information given in Foundation and Earth). Claims were made as early as 1942 that 61 Cygni had a planetary system, though to date, none has been verified, and Asimov was aware of these claims.

Alpha is a fictional planet orbiting the larger of the two stars in the Alpha Centauri system.

In Asimov's Foundation Series, Alpha Centauri is cited by Lord Dorwin as one of the solar systems where humankind potentially originated. The others are Sol, Sirius, 61 Cygni and Arcturus. Beyond mentioning that it is in the Sirius Sector, Dorwin gives no further details.

In a later book, Foundation and Earth, Alpha is a planet orbiting the larger of the two stars in the Alpha Centauri system. Golan Trevize discovers Alpha when he attempts to find the location of Earth by locating the center of a 'best sphere' made from the coordinates of the 50 Spacer worlds.

The planet is discovered to be entirely covered by an ocean, with the exception of a single island with a surface area of 15,000 square kilometres. (For comparison, Sicily is just over 25,000 square kilometres.) The inhabitants call it New Earth and live a simple lifestyle. While the inhabitants seem to be warm and welcoming, co-existing peacefully in an egalitarian society, this might be a show designed to put foreign visitors at ease while they were infected with a virus. The only certain facts about New Earth culture are that both women and men are completely shirtless, weather permitting, and the men engage in long sea voyages to fish.

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