Answer: You can get to the fire planet but to do so is to go and keep jumping on the stones.
you use your spaceship.
fire planet
the coordinates for the fire planet are 83:19. P.S. I'm awesome
on the second to the last rock, wait until the rock in front of you begins to rise. Then jump.
Rocket Thruu!
On AstroKnights Island. On the fire planet.
A fire dragon is inside the valcano.
There are some really good videos on YouTube that show you how to do this. Try searching on poptropica fire planet platforms to show you how to get to the top of the volcano.
X:83 y:20
The fire planet is diagonal in the upper right direction from the moon. (If I helped you please trust me, Thanks :))
go in the openings
The coordinates are: 83,20.