The '''solar system''' consists of the [[Sun]] and its associated objects and phenomena, including the [[Earth]], the planet on which we live. It is the best-known example of a '''planetary  system''', which more generally is composed of one or more stars and whatever matter ([[planet|planets]], rocks, dust) is gravitationally bound to them.

The principal component of the solar system is the
[[Sun]], a comparatively small star which nevertheless contains 99.9 percent of the mass of the system and dominates it gravitationally. In addition, because of its large mass, the interior of the Sun achieves the density necessary to sustain nuclear fusion, releasing enormous amounts of energy, some of which is radiated into space in the form of electromagnetic radiation, mostly visible light, and a flow of charged particles called the solar wind, which profoundly affects the environment of the solar system. The remaining small amount of mass outside the Sun includes the nine planets ([[Mercury]], [[Venus]], [[Earth]], [[Mars]],
[[Jupiter]], [[Saturn]], [[Uranus]], [[Neptune]] and [[Pluto]]), and their
[[moon]]s and [[ring system]]s. In addition, there are [[asteroid]]s,
[[comet]]s, [[trans-Neptunian objects]] and [[Kuiper Belt]] objects, a theorized [[Oort cloud]], and interplanetary [[dust]] and [[gas]].

'''Origin and Evolution of the Solar System'''

The solar system as a whole is currently believed to have formed through the normal process of star formation which produced the Sun itself, rather than through some special process (such as a stellar near-collision) as was once thought. The process is believed to have begun with the gravitational collapse of a cloud of interstellar gas and dust to produce what is called the solar nebula.


'''Discovery and Exploration of the Solar System'''

Because of the geocentric perspective from which humans viewed the solar system, its nature and structure were long misperceived.
The apparent motions of solar system objects as viewed from a moving Earth were believed to be their actual motions about a stationary Earth. In addition, many solar system objects and phenomena are not directly sensible by humans without technical aids. Thus both conceptual and technological advances were required in order for the solar system to be correctly understood. 

The first and most fundamental of these advances was the Copernican Revolution, which adopted a heliocentric model for the motions of the planets. Indeed, the term "'''solar''' system" itself derives from this perspective. But the most important consequences of this new perception came not from the central position of the Sun, but from the orbital position of the Earth, which suggested that the Earth was itself a planet, and the planets other Earths. This was the first indication of the true nature of the planets. Also, the lack of perceptible stellar parallax despite the Earth's orbital motion indicated the extreme remoteness of the fixed stars, which prompted the speculation that they could be objects similar to the Sun, perhaps with planets of their own.

<b>Major Planets of the Solar System - Equatorial diameter (miles)</b>

* Mercury 3,031
* Venus 7,520
* Earth 7,926
* Mars 4,200
* Jupiter 88,700
* Saturn 74,600
* Uranus 31,570
* Neptune 30,200
* Pluto 1,900


<b> Major Planets of the Solar System - Mass in relation to the Earth's mass</b>
* Mercury 0.06
* Venus   0.82
* Earth   1.00
* Mars    0.11
* Jupiter 318.00
* Saturn  95.00
* Uranus  14.60
* Neptune 17.20
* Pluto   0.0017

/Talk
