You will find a knight on each of the planets on the Queen's list:
Sir Cador - Jungle Planet (get the Laser Lance from the jungle)
Sir Gawain - Ice Planet (gives you the Force Shield)
Sir Peleas - Fire Planet (gives you the Ice Arrow)
When you defeat the large (boss) monster on each planet, the knight will come with you. When you have all three knights with you, you can travel to the secret asteroid at X-11 Y-82 and pull out the Golden Key that opens the portal there.
You do not get or use a bucket on Astro Knights Island.
There is no treasure chest on Astro Knights Island.
There are no bird eggs in astro knights island.
How do you talk to the girl in the hay loft at astro knights island?
its on the island
On every island you have to be the one to save whatever needs saving. That includes the kingdom in Astro Knights Island.
it is in the left
Astro Knights
With Mordred
Once you have built a new spaceship on Astro Knights Island, it will park on top of the castle whenever you leave the island.
on astro knights island
To see the solar system on Astro Knights island, go to the Planetarium. (not part of the game, but an interesting view)