Interplanetary space refers to the region of outer space between planets in a solar system. Interplanetary space is roughly defined by the end of substantial influence from a local planet's gravity well, with more influence from the primary object of the system, in our solar system's case, the Sun. Outer space (also called just space) as a name for a region, refers to the relatively empty parts of the Universe, outside the atmospheres of celestial bodies. ... A planet in common parlance is a large object in orbit around a star that is not a star itself. ... Presentation of the solar system (not to scale) The solar system consists of the Sun, all the objects that orbit around it, including meteoroids, planetoids, comets, moons, and planets, and the tenuous plasma of the interplanetary medium. ... A gravity well is the scientific/science fictional term for the distortion in space-time caused by a massive body such as a planet. ... By ancient tradition, the Sun is the light in the heavens whose presence is day and whose absence is night. ...