I missed the recent competition based around "Luck" but this probably would have been my entry. One of my early and certainly not best astrophotography shots was attempting to capture the Milky Way over a large railway viaduct in North Yorkshire, UK.
The shot was interrupted by an extremely bright meteoroid and on examination a satellite flare (and aircraft). Not sure of the chances of this ever happening but they've got to be reasonably slim! So not my best but certainly my luckiest!
Anyone else have a lucky astro shot?