Patricia, when I have dark pictures like that or pictures that are to bright, I always try the "Screen"(if they are to dark) or "multiply"(to light) options in Layers first… for your picture, try going to window and open the layers window.. when there, copy the background layer by dragging the background layer down to the little square next to the trash can on the bottom of the layers popup box.. uncheck the eyeball on the original background then copy the background copy you just made, just like before.. at the top of the box right under layers there is a box that says "normal" change it to screen.. you will notice a change in the picture.. but it is still too dark so repeat the copy part with this new layer.. the new layer produced will already be allocated as "screen" so the picture should change again.. I did this till I had 7 copies with your picture… (there are sliders called "opacity" and "fill" located besides the screen box, these can be adjusted for fine tuning when you get to the level of picture you want) .. Then save as PSD with layers checked for editorial use later…. then as a JPG for computer/web/mail uses.. this pretty well conserves your original and provides a picture as seen:
this is the first time I tried to put a picture on here so if it does not work… go to: <
http://tinyurl.com/y7npua>
after all this you can just use the history brush to bring back the sky..