Contrary to our initial ignorant thoughts, the crater has nothing to do with meteors or asteroids. Rather is is a volcanic land form, and apparently, or word on the street is that it was a massive volcanic mountain about the same size as Kilimanjaro. Its base was however full of volcanic vents and eventually the mountain collapsed in on itself creating a massive basin. It truly is one of the most amazing places i have ever been to, and i think we all agree, that it is somewhere we will all visit again some day!
We also spent a night camping inside the reserve - on the crater's rim. Initially we thought that most of the game was inside the crater, but we took a small night drive on which we saw lion twice, hyenas, elephants, Buffalo, and a massive herd of spring hares (kept us guessing for quite a while). And since the Tanzanians are about as keen on game fences as the Kenyans, we had a fairly entertaining night of camping. First a Buffalo interrupted washing dishes, then bush-pigs attacked our food crate, and later hyenas bit holes into our beers :)