I have had Ambitions since the day it launched and I have only had two meteor strikes (I am not counting Seasons + Ambitions alien meteor strikes, since you control those). The two meteor strikes oddly happened to me this past year. One of them hit a park, other one near the military base. I am pretty sure it wasn't even on any lot so to speak. Because of that really no items were damaged, and if I recall correctly tha ground will retain it's shape at some point. It is quite easy to get your sims away from the meteor though, so I would not be worried about it. All in all I would say that they are really rare. I know other players who have had Ambitions since the beginning and have only encountered one or no meteor strikes.
I think meteor strikes are caused by having sims be in outdoors. Telescoping might increase the change and it also causes sims to be at the same spot for a long time, which I think is one of the factors for meteor strikes.
