Interplanetary (adjective)

1. Occurring or existing between planets.
2. Relating to or involving travel or communication between planets.
3. Relating to or dealing with the study of planets or the solar system as a whole.

Origin:

From inter- ("between") + planetary.

Examples:

1. Interplanetary missions have been launched to explore other planets.
2. The interplanetary probe is on its way to Mars.
3. The interplanetary dust particles are constantly bombarding the Earth.
4. Interplanetary travel is a key goal of NASA.
5. Interplanetary communication is a major challenge for scientists.