A number of short phrases have come into use to describe various extra-solar planets that could be termed planet types. The planets Earth, Jupiter, and Neptune are often used to designate the size as are super-Earth and mega-Earth, the latter two which may simply designate the size or may also suggest it is rocky. The adjectives hot and warm are added to designate a planet closer to the star than its habitable zone, e.g., a planet with a week-long orbit around a Sun-like star. The terms gas planet, liquid planet, and rocky planet are used to designate its primary constituents. Hot typically means very close to the star, perhaps an orbit of a few days and temperatures in thousands of degrees. Warm has been used for planets with close to Earth temperatures or for considerably warmer.
Based on solar system models;