STRINGS.CODEX.EXOBASESDLC1.PARAGRAPH_2
To scan space and see nearby interstellar destinations a Telescope must first be built on the surface of a Planetoid. Sending an Orbital Data Collection Lab into orbit around a Planetoid, and having a Cartographic Module attached to a rocket can also reveal places on a Starmap.
Always check engine fuel to determine if your rocket can reach its destination, keeping in mind that rockets can only land on Planetoids with a Rocket Platform on it. Notably, some modules, like Rover's Modules and Trailblazer Modules, can be sent to the surface of a Planetoid from a rocket in orbit.
If a rocket runs out of fuel before it reaches a viable landing site, it will become stranded.