Wierd Experience

Around 3.00am this morning, i was woken by the dogs around the campo all barking like mad,then i heard the sound of what seemed like a very powerfull engine go overhead, i sat up in bed and looked out the window and the sky was a bright red which faded silhouetting the hills over Blanca. I jumped out of bed and went to the window but by then the red glow had faded completely,and there was no sound,(even the dogs had stopped barking). what ever it was moved very fast although the engine seemed like it was just idling, because this happened in no more than 5 or 6 seconds. Today we have been smelling a indistiguishable chemical type of scent in the air, Was the happening chemical spraying? was it a UFO?