Planetary engineering is the practice of deliberately modifying the environment of a planet or moon to suit the needs of a particular population or to make it habitable for humans.

Elon Musk's vision is to create a multi-planetary civilization.

The planetary gears in the transmission system are responsible for transferring power between different gears.

The proto-planetary disk is a key component in the formation of planets.

The planetary gear train is used in many automotive transmissions.

Planetary gear trains are commonly used in automotive transmissions.

The planetary nebula nuclei are the remnants of dying stars.

The planetary nebula's nucleus is composed of hot, dense matter.