Joe: If you can play on an unlimited number of planets,
it would make no sense that each is stored in the memory.
A much better idea is to have autogenerated planets.
Just a (pseudo) random number, and based on it are all the relevant parameters.
When looking for a new planet you could perform some tests to determine the value of this random number.
And from there, discover the values of the parameters that you are interested in.
And look for a planet which meets your criteria.
Again, use automated scripts for this, to speed up the task.
This way after many iterations you could maybe find a planet with an extremely high value of a parameter which is, for example, tree growth rate.