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Contents
1. Introduction
2. Earth
3. Other planets of the Solar system
4. Conclusion留学生论文代写网提供英文论文代写,英国留学生论文代写,澳洲留学生论文代写,留学生essay.QQ在线客服：949925041.美国留学生论文代写,留学生商科论文代写,留学生硕士毕业论文代写,代写dissertation，记住我们的网址：

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Introduction
Solar system includes nine planets each of them is a unique space object which possess features that make them different from each other. Probably the most particular planet is Earth, which is the only planet where variety forms of life co-exist. At the same time other planets are also interesting to explore and compare that will provide an opportunity to better understand the solar system at large, its origin and the processes it undergoes in particular. It is particularly important to compare Earth with other planet because of its uniqueness and such a comparison will probably reveal the mystery of the only planet where life exists.
Earth
Earth is one of the most particular planet of the solar system. It is also known as Terra, or else it is called the third planet from the Sun because among the nine planet of the solar system it is the third closest to the star. It is the largest of the solar system’s terrestrial planets and it is the only planetary body that modern science confirms as harbouring life. The planet is relatively young in astronomic terms for it was formed around 4,5 billion years ago and shortly thereafter acquired its only natural satellite, the Moon.
Speaking about the structure of the planet, it should be said that the Earth consists of several atmospheric, hydrologic and mainly geologic layers. However, in comparative analysis of the Earth and other planets geologic layer would be particularly noteworthy since other planets basically lacks atmosphere and hydrologic layers identical to terrestrial. On analysing the structure of the Earth, it should pointed out that it is chemically divided into an outer silicate crust, a highly viscous mantle, a liquid outer core that is much less viscous than mantle and a solid inner core. The liquid outer core gives rise to a weak magnetic field due to the convection of its electrically conductive material.
It is noteworthy that an important source of information about the inner structure of the Earth are volcanoes and cracks in the ocean floors as well as the analysis of the mountains structure for many of the rocks now making up the Earth’s crust formed less than 100 million years ago. At the same time it should be pointed out that the oldest known mineral grains are 4.4 billion years old, indicating that the Earth has had a solid crust for at least that long.
It should be emphasized that the average density of the Earth is 5515 kg/m3, making it the densest planet in the Solar system. The average density of the surface is only 300 kg/m3 indicates at the presence of denser materials within the core of the earth. The core is divided into inner and outer. The former is believed to be solid and consists of iron and some nickel while the latter is liquid and consists of liquid iron mixed with liquid nickel and lighter materials. It is believed that convection in the outer core, combined with the rotation of the Earth, gives rise to the Earth magnetic field. The mantle is believed to be solid/plastic rich in iron and magnesium.
Furthermore, it should be pointed out that the surface of the Earth is constantly changing and several processes influence 本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。