Golden Eggsteroid 8 is located on level 4-24 of Angry Birds Space Utopia. Zoom out and you will see the Golden Eggsteroid hidden in the bushes on the top right. Just fire the Lazer Bird up and redirect into it. Once you hit the egg, you’ll immediately be transported via a wormhole to the level.
This level is hard because you have to use only one bird for three stars.
One strategy 3-starring this level is to fling the Orange Bird into the group of small square wood blocks, expanding just before it reaches them so it pushes the blocks all over the place. With a little luck and this will cause a chain reaction exploding the TNT and popping all the pigs.