A batch of Starfield details appears to have leaked, and have been partially corroborated by a recent trailer.
The details, shared via Reddit (opens in new tab), appear to explain much of the galaxy that Bethesda has created and how players will interact with it. It's claimed that you'll be able to choose your starting location, picking different planets or space stations each time you replay the game. Depending on where you are, you'll reportedly be able to experience gravity in different ways, with both visual and gameplay changes in effect.
The leak also claims that there are multiple planets to explore, and that each of the "dozens" of planets is bigger than Skyrim's map. You'll be able to make some of them your home, as Fallout 4's settlement building system is also said to be returning, albeit "much improved." An entire questline, which sounds similar to Fallout 4's approach, appears to be in place around this system, and will apparently be given out by an NPC named Branson Garvey, presumably a nod to the Commonwealth's Preston Garvey.
While a leak like this is usually something worth remaining highly sceptical of, two details may hint at its accuracy. Yesterday, Bethesda released the new Starfield 'Settled Systems' trailer, outlining the time period that the game will take place in - around the year 2330 - and a few other details, one of which is a religious cult faction that you'll be able to join.
This leak, which originated over a month ago, claims that the game will take place in the 2320s (potentially referencing the conflict that takes place shortly before the time of the game), and states "there is a cult faction who believe that Jesus/God came from the stars and [is] looking for his real birthplace." Details can always change, and it's also possible that both of these clues were simply lucky guesses, but they do lend the leak just a hint of legitimacy.
Update: The original poster has responded on their thread saying that they made all of the details up. The faked post was an attempt to encourage those with accurate information to correct the false details, but was unsuccessful.