Balloon Kid takes place in a small part of an unnamed, Earth-like world.
If they're able to locate another Earth-like world, they'll eventually plant us there.
New space instruments under development are expected to directly observe planets around other stars, perhaps even some Earth-like worlds.
It could not be an Earth-like world.
The first stop is supposed to be an interesting little Earth-like world about twenty light-years from here.
Hadley - Earth-like world with a large city.
It might theoretically show features on Earth-like worlds around other stars.
To find Earth-like worlds will need a new generation of telescopes.
And we have no assurance of finding another Earth-like world.
The number of Earth-like worlds per planetary system.