How to get three stars in angry birds space world 1 level 27
This one took me a while to figure out, but here it goes. To get three stars on this level you need to wipe the planet with just the one bird. The way to do so is to fire the first bird directly towards the ice structure on the smaller planet. As the bird it half way there press down on your screen so the bird splits up. The upper and the lower bird will now have to bounce of the surface of the small planet and hit the crate of explosives. This will make just about all things on the big planets surface blow up and get you all the points needed to get your phone those stars.
A video guide of the whole thing can be seen below.