Solar System

The Solar System is the collection of astronomical objects that are within the gravitational influence of the star called the Sun. The Solar System is located in the Milky Way galaxy, in the inner rim of the Orion-Cygnus arm of said galaxy. In the Solar System contains 13 known planets, 8 known major planets and 5 known dwarf planets. Of the 8 known major planets, four of them are terrestrial planets (Mercury, Venus, Earth, and Mars). The other four known major planets are giant planets, which can be again divided into gas giant planets (Jupiter and Saturn) and ice giant planets (Uranus and Neptune). Out of all of these planets, Earth is the only one known with confirmed life and is the homeworld of humanity.
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== Formation ==
The Solar System formed approximately 4.6 billion years ago when a molecular cloud of gas and dust coalesced into many other stars; one of these stars being the Sun. Over time, as the Sun formed, a protoplanetary disk emerged to orbit the Sun, which later coalesced into the planets and other objects. Closer to the Sun, only high boiling point materials like iron and rock could exist in the condensed form, giving the rise of terrestrial planets orbiting close to the Sun, including the Earth. Farther away from the Sun, beyond the solar frost line, it was cold enough for volatile materials to exist in the condensed form, and so is the place where the giant planets formed, orbiting the Sun at a much farther distance. The preceding nebula in which the Sun formed in had only a small fraction of high boiling point materials, since volatile materials were more plentiful, which is the reason why the giant planets are much bigger than the terrestrial planets.
Because of a protoplanetary disk's almost always nature to rotate in the same direction as it's star's rotation, all of the planets and most other astronomical objects gravitationally bound to the Sun orbit the Sun in the same direction as the Sun's axial rotation. Similar to this, large or small moons orbiting the planets of the Solar System also orbit their respective planet in the same manner, because the planets themselves had or have disks of their own, called circumplanetary disks. There are exceptions tho however.
== About the Solar System ==
=== The Sun ===
The Sun is, of course, the star at the center of the Solar System, in which all of the planets and other astronomical objects of it orbit. It is a typical and relatively common type of star known as a yellow dwarf star; more specifically, it is a type of star known as a G-type main sequence star of spectral type G2V according to the Morgan-Keenan stellar classification scheme made by humanity. The "G2" means that it has an average surface temperature of approximately 5800 Kelvin and the "V" means that it is a main sequence star currently fusing hydrogen into helium in it's core through nuclear fusion; the most common stage that a star is in. 
Despite being a relatively insignificant star in the universe, the Sun holds a special place to life on the terrestrial planet Earth, as almost all life on Earth depend on the Sun's heat and radiation output to sustain itself. Although it is a life-bearing star, the Sun still emits things that could be considered harmful to life on Earth, like for example ionizing radiation in the form of ultraviolet radiation and it's stellar wind. The way as to how life on Earth is protected from these harmful activity of the Sun will is discussed in the Earth section. 
=== The Planets ===
As said before, there are 8 known major planets and 5 known dwarf planets orbiting the Sun.
==== Terrestrial planets ====
===== Mercury =====
 
Category:Real objects
Category:Objects
Category:Planetary system