First, spoilers for the first few chapters below, if you care about such things. This (neat!) article and the comments here (so far) miss/skip a few details (o

First, spoilers for the first few chapters below, if you care about such things. This (neat!) article and the comments here (so far) miss/skip a few details (or my mind is making fake memories again). 1. Regarding the destruction of Earth - IIRC, while the pounding (and subsequent geological and atmospheric responses) the Earth was to receive was an ELE, the real kick in the teeth was the cumulative heat generated as much of a moon's worth of mass burned up in the atmosphere. 2. Regarding whether the moon would just sit there fragmented or mirror the descriptions of the book - IIRC, the moon didn't just break, it was _broken_ (by what is never known). So whatever thing wielding a massive physics bat did that, it can also impart all sorts of momentum. Pretty easy to say that if you can get the end result from SOME starting conditions, that those starting conditions could have been created by the Deus Ex Machina. I know no orbital physics, but isn't the solar system is a great example of showing how big rocks in orbit become fewer, smaller rocks given enough iterations? So far as I know, asteroids occasionally manage to strike one another (defying the vastness of space by their numbers and persistence) and asteroids can capture smaller bits, but on the whole asteroids are getting smaller, not larger (albeit at a cosmically slow pace). 'Course, I could be wrong. Had an hour long argument with a friend who said that there was no angle that would allow one mass to capture another approaching mass approaching into orbit, while I was relying on my experience of reading of various suspected "captures". After much googling, we decided he was right from a two-body position, but that the Sun ( or other mass) can provide the necessary nudge to turn a swingby into a lasting orbit, so I could be right too.