Some or all of the features on this page requires the Gas Giants Expansion in-app purchase.
The Planets Expansion is one of the 4 expansion packs for the game. Once purchased, it adds Jupiter to the player's SFS universe, along with its four Galilean moons (Io, Europa, Ganymede, and Callisto). The Planets Expansion can be purchased by itself for $3.99 (USD) or it can be purchased with the other expansions for $7.49 (USD). In 1.6, it may be split into the Gas Giants Expansion and Ice Giants Expansion.
The Planets Expansion in-app purchase page