All you need to travel to another world is coal. You can find it in dirt and rock fairly easily on the surface, or with a little digging. Teleport up to your ship, head for your fuel tank towards the front of the ship, and put some coal in your fuel tank.
Yes, your interstellar spaceship runs off of basic fossil fuels.
Wood no longer acts as a fuel source for your spaceship, but you can now smelt 10 Unrefined Wood into a piece of coal, as of the Frustrated Koala patch
Coal no longer acts as As of 1.0 stable, only the purple colored Crystal Erchius and Liquid Erchius Fuel (requires upgraded Matter Manipulator) found on the surface and in the caverns on Moons (requires Breathing EPP to visit) can be used to fuel for ayour spaceship. As ofNote that travelling between planets in the same system Upbeat Giraffe patch:does not require fuel.
radioactive ores or the new Liquid Erchius Fuel that now appears in Moon biomes
Are what'sLiquid Erchius Fuel can also be bought from the Infinity Express store on the Outpost, but at 5 pixels per unit it is rather expensive and should only be used to fuel your spaceshipas a last resort.