So, before we get into looking at the universe and all of the galaxies you can see, let’s talk about our own solar system. Did you know that before Galileo came on to the scene, everyone thought the planets and the sun revolved around the Earth? Galileo, through his many observations and improvements on the telescope, thought that the theories of Nicolas Copernicus where the truth. Copernicus theorized that the Earth was not the center of the universe, but rather the sun was. Well, we know now that it is not the center of the universe, but rather the center of our galaxy. The solar system can be thought of in various parts: the inner solar system, which is made up of 4 planets, Venus, Mercury, Earth and Mars; the mid solar system, made up of the asteroid belt and several comets; and finally the outer planets consisting of Jupiter, Saturn, Uranus, and Neptune. Where is Pluto, you ask?  It was classified a planet up until August 24, 2006 when the International Astronomical Union (or the IAU for short) decided that a planet “is any body in orbit around the Sun that has enough mass to form itself into a spherical shape and has cleared its immediate neighborhood of smaller objects.” Pluto then became known as a “dwarf planet” which is the same as a planet essentially, but it has not cleared its neighborhood of smaller objects. Poor Pluto, oh well. So let’s look at the main parts of our Solar System in order.

Sun		Venus		Mercury		Earth
Mars		Jupiter		Saturn		Uranus

Neptune

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