The ExtraPlanets mod is an add-on for GalactiCraft that will complement and expand the main mod by adding new types of rockets, planets, and new resources to the game.

In total, the addon adds 4-10 new rockets (depending on the version of the game), 10+ new planets that you can fly to, and in the future the author plans to add about 12 more planets. Among the planets are Mercury, Jupiter, Uranus, Neptune, Pluto, Eris, Kepler22b, Ceres and others.
Each planet is unique in its own way, has its own ecosystem, style and resources. In addition to the planets, there are also moons, for example, the moons of Uranus, Neptune, Mars, Jupiter, including the famous IO, Europa, Ganymede, Callistro.

All these planets add many new blocks and even types of vegetation, mobs (on certain versions only), you can use new types of spacesuits, create your own space bases on new planets and explore them with cars (ala moon rover or rover.)