You can go to any of the three planets in any order. Jungle Planet X-15 Y-15 Ice Planet X-73 Y-83 Fire Planet X-83 Y-20 (The fire planet is the hardest, but you must beat all three.)
The lava is the first challenge on the Fire Planet (X-83 Y-20), which is up and to the right of the planet Poptropica. (see related question)
he is on an asteroid in the asteroid belt i think the cooridnates are 12x 80y but get all the knights first!
The game designers are making the player think, which makes Astro Knights harder than the previous games. Unlike the first five jumps over the lava, the 6th jump appears impossible, until you jump while BOTH platforms are moving DOWN.
It doesn't matter which order as long as you complete all three planets (jungle, fire, and ice). Fire is the hardest of the three.
This is the first item on the island. Go to the Mordred Musseum and spend it. Get the library slip and go to the castle library.
To catch the mechanical mouse, in the Princess's Maid's room (castle first floor left).
The first time, you have no choice. Fix the saucer and launch it (see the related question). Once you have a spaceship, you can land on Poptropica, the Pewter Moon, or any planet by clicking on it. (The exception is the ice planet, see related question)
The library is in the Castle, to the right on the first floor. The three areas of the kingdom are the Village, the Castle, and the Mill.
In the Maid's room (castle first floor left) you will find a mechanical mouse.
In Astro Knights Island on Poptropica, the fuel for the hovercraft can be found in the fuel canisters located next to the dock where you first arrive on the island. You need to collect the fuel canister and use it to power the hovercraft to cross the toxic swamp.
In the Maid's room (castle first floor left), feed the cheese to the robot mouse.
You show her the message that you get from the castle (maid's room, first floor left).