Eros, a previously Formic planet that is now home of Command School, has nothing to do with the real-life asteroid of the same name that sits between Mars and Jupiter. "Our Eros" is a tiny (only 7 miles wide), potato-shaped rock that has no atmosphere, almost no gravity, and certainly couldn't support underground structures.
From our interview with the set designers:
We fundamentally changed Eros. Eros was the specific asteroid in the book. It’s the one called Eros. It has that dimension that it’s all interior spaces and Gavin just felt that it wasn’t conducive to… the central problem is that you need to be exposed to what Formic society is like. What does one of their worlds really look like? What does one of their societies really look like. And again it’s Gavin’s take that it should be kind of awe inspiring to us. It’s not just “Oh my god, there’s so many of them and they’re creepy and they all live underground.” It should be like something that has height and has scale and has beauty. And if we don’t really get to go to the formic planet ever, then how do we go to one of their spaces? And that was the answer, was Eros is not an asteroid with little tube holes in it, it’s a proper planetoid with an atmosphere that would look a bit like the formic home planet. It gives you a preview, it gives Ender a preview, of what their world and their society really feels like. So it’s just different. We are on a planetoid, it’s not small, that doesn’t need formic generated gravity. It’s just different.Source: Ender News
- Sean Haworth