Golden Eggsteroid 9 is located on level 6-24 of Angry Birds Space Pig Dipper. The Golden Eggsteroid is slightly below the normal line of sight between the slingshot and the main target. While there are several birds that can reach it, the Lazer Bird is easiest. Once you hit the egg, you'll immediately be transported via a wormhole to the level.
Reach the target score is quite hard.
One strategy 3-starring this level is to send the first Terence vertically, following the tomatoes and popping three pigs. Send the next Terence slightly below horizontal to the right, popping the last pig. Before your final score tallies, send one more horizontally leftward, since there are more than five tomatoes at 2,000 points each.