Certain planets require special gear; players will be unable to beam to these planets unless they meet the requirements.
Players can activate beam transport by clicking the 'Teleport Button' in the UI. On planets this button has an arrow pointing up, and on ships the arrow is pointing down. Each planet has a default point that players will beam down to, but players will eventually have the ability to craft an object to relocate their spawn point on the planet.
The player is able to beam back up to the ship from underground if the background is removed and they are still close to the surface.
In its predecessor's (Terraria) term, height 0 is the minimum height before you can beam back up from underground.