In Angry Birds Space for the iPhone, iPad, and Android platforms, there are six golden eggs you can find that will unlock six bonus levels in the Eggsteroids world. These hidden levels are throwbacks to old school games, like Super Mario, Space Invaders, etc.
1. The first golden egg can be found in 1-9, hidden in plain sight behind a tiny bush.
2. The second golden egg is found in 1-20, hiding in the bushes on the top of the planet. You may get this one without even trying.
3. The third golden egg can be found in 2-13 on the planet at the bottom of the screen. Just shoot the purple bird down, and tap near the golden egg to have it shoot there.
4. The fourth golden egg can be found in 2-25 on the planet at the bottom of the screen. Like the previous egg, just shoot the purple bird down, and tap near the golden egg to have it shoot there.
5. The fifth golden egg is hidden completely in the snow on 2-28.
6. There is a new golden egg hidden in the Fry Me To The Moon world, which is on 3-10. Use the purple bird, shoot it off to the left, and tap the golden egg to make it fly to it.