On a giant asteroid in the asteroid belt.
you just click it.
The small key in Astro Knights Island is for Mordred's secret hideout. When you come to that wind mill area, move the hay bales apart and use the key on that.
the door that's locked
just click it.
The secret room between the hay bales!
it's in the astro belt at the bottom left coner area.you have to defeat the planets and have all the knights with you to get to the castle. once you have all the knights with you go to the astro belt then, go to the sword key and pull it out. after that you jump in the spining wheel thing.
The key on the big asteroid in Astro Knights Poptropica is located in the lower right corner of the asteroid near the entrance to the base. You need to use the bridge to reach it, but be careful of the falling debris.
The key unlocks mordreds secret lab. You can get there by seperating the two hay bales.
Go to the place where the order is in. Talk to the guy with pimples on his face. He gives you the key. That is how to get the key for astro knights on poptropica.
There are no bird eggs in astro knights island.
You do not get or use a bucket on Astro Knights Island.
The key opens the entrance to Mordred's secret underground lab. The entrance is between the two hay bales in the farm area near the mill. (see related question)