Chapter 2 Section 1 Planet Earth
Our Solar System - Getting to know Earth
Our Solar System
The sun remains in the center, which is about 109 times wider than the Earth. The amount of matter it contains creates a strong pull of gravity which keeps the earth and other objects revolving around it.
Planets are the largest objects in our solar system- nine exist, each with their own orbit.
Astroids are small, planetlike objects. They are found in a region called the astroid belt.
Comets are made of icy dust particles and frozen gases.
Meteoroids are pieces of space debris made of rock and iron.
Meteorites are those that collide with the Earth.
Getting to know the Earth
70% of the planet's surface is water. Bodies of water make up part of the earth called the hydrosphere. 30% of the earth's surface is land. Land makes up a part of the earth called the lithosphere - the earth's crust. The air we breathe is part of Earth's atmosphere. All people, animals, and plants live in the earth's atmosphere. The part of the earth that supports life is the biosphere. Life cannot exist outside of the biosphere without the assistance of life-support systems.
Earth's landforms are made out of different shapes or elevation , including rivers , lakes , and streams. There are also underwater landforms, in some places the ocean floor is a flat plain and other parts contain mountain ranges, cliffs, valleys, and deep trenches.
Great contrasts exist in the heights and depths of the earth's surface, such as the highest point: Mount Everest and the deepest: The Mariana Trench. Other than these there are many other natural features that have developed over the years.