You have to click 10 of the cards exactly once each to flip them all over :
if you mean the planet in the asteroid belt then it is X:11 Y:82
you have to finish the puzzle then click on the door
When you have all three knights with you, they suggest you look for a giant asteroid, which happens to be at X-11 Y-82 in the Asteroid Belt.
She isn't on a planet.she is on a asteroid (if you are talking about astro-knights island)
No, because you need the three knights to go with you. (see related question)
On a giant asteroid in the asteroid belt.
Once you have beaten all three planets and have all three knights with you, travel to the secret asteroid in the Asteroid Belt (down and left in the solar system). The asteroid is at X-11 Y-84.
You do not get or use a bucket on Astro Knights Island.
When you have all three knights but can't find the Princess, the knights suggest you look for a fabled "giant asteroid". There is one in the Asteroid Belt near X-11, Y-82.
If you have all three Knights with you, proceed to the Secret Asteroid (X-11 Y-82) and rescue the Princess. If not, there's nothing to do but shoot space rocks.
There is no treasure chest on Astro Knights Island.
After you beat all three planets (fire, ice, jungle) and have all three Space Knights with you, you can go to the secret planetoid at X-11 Y-64 in the asteroid belt. Pull the Golden Key from the crystal to open the portal.