Solar System
The planetary system of which the Earth is a member.
The number of bodies popularly considered part of Earth's Solar System has gradually increased over the millennia, and more radically over the past few centuries. For some thousands of years, the perceptions of nonwizardly human beings included only the two innermost and three outermost planets, now known as Mercury, Venus, Mars, Jupiter and Saturn -- in other words, the brother and sister worlds visible from Earth with the naked eye. This situation began to change with the invention of the telescope, and the outer planets Uranus and Neptune were added in the later centuries of the last millennium, along with Pluto, whose status as a planet has become controversial as of this writing. The system also contains numerous moons associated with the various planets, an asteroid belt between the orbits of Mars and Jupiter, and the Oort Cloud, a large zone of post-formation detritus and minor bodies left over from the Solar System's formation.
The term "solar system" is also used in lower case to describe other planetary systems. The name of the star which is the system's primary, or the system's main inhabited planet is usually prepended (as in, for example, "the Rirhath B solar system"), sometimes in an adjectival form (as in "the Wellakhit solar system", indicating that the star is the one orbited by the planet Wellakh).