So I was out at the track running some tests today. We're right at the edge of town. Fairly literally actually... to the North it's semi-industrial park, to the South and East it's fields and bush. It's just open enough to make me FREEZE while I was out there, this being the cold time of year - just warm enough to be damp, and we're still used to summer.
So anyway, I was out at the track when I hear a sudden bang. I wasn't too worried about it, because we weren't running a test at the moment, we were in fact backing the graders up after running a test. However it's still not normally a good thing, and this was from the direction of the bush - the only thing between me and it was graders, so I couldn't think what else could have caused it. I asked the test engineer, who looked markedly unworried (another good sign). I'm sure he was amused when he told me what the noise was.