This page contains additional information for the study of the solar system for Grade 7.1.

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Although it is still a mystery as to why the Earth’s atmosphere formed in the way it did, the atmosphere’s formation was essential to life forming on our planet.

At first, the atmosphere would not have been able to support life as we know it. It was composed of different amounts of water, carbon dioxide and monoxide, nitrogen, hydrogen, hydrogen chloride and oxygen than it is now. There was very little oxygen, and much larger amounts of other gasses in the air.. Earth was no more than an extremely hot and large rock, that soon split into the Earth and moon . The most important factor, many believe, that contributed to the formation of life on Earth, was water.

According the Big Bang theory, the universe is full of dust, thought to be one of the results of the Big Bang.
About 5 billion years ago, a nebula, a cloud of dust and gas, was the start of the solar system. A solar system forms around a star, which is born inside a nebula. Planets are the left-over matter after a start forms. The gravitational pull of a star pulls the planets into orbit around it. Our solar system has eight or nine planets (there is a current dispute on whether Pluto is actually a planet), which are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.