Planet Earth

Section 1

Our Solar System

our sun is the center of our solar system. it is about 109 times wider than earth, the suns gigantic size and enormous mass-the amount of matter it contains-creates a strong pull of gravity.

The Planets: neighbors in space

besides the sun, planets are the largest objects in our solar system. At least nine planets exist, and they are all in their own orbit around our sun. Mercury, Venus, Earth, and Mars are the inner most planets, or those closest to our sun. Farthest away from our sun are outer planets: Jupiter, Saturn, Uranus, Neptune, AND Pluto.

All of the planets Vary in size. Jupiter being the largest and pluto being the smallest.

Earth ranks 5th in size among the other planets. All of the planets besides Mercury, and Venus have moons, smaller spheres or satellites orbit them.

Comets, Asteroids, and Meteoroids

Along with the planets, thousands of small objects, including comets, asteroids, and meteoroids, revolve around the sun.

Asteroids are small, funny looking irregular shaped, planet like objects. they are usually found between the orbits of Mars and Jupiter in a region called the asteroid belt.

Comets, which are made of icy particles of dust and frozen gases, look like bright orbs with long, feathery tails.

Meteoroids are pieces of space debris, chunks of iron and rock. when they sometimes enter our atmosphere, friction most of the time usually burns them up before reaching earths surface.

Water, Land, and Air

The earths surface is made up of water and land. around 70% of earths surface is water, which gives the earth its deep blue appearance that astronauts see from space. Lakes, Oceans, Rivers, and other bodies of water make up an area of the earth called the hydrosphere.

Abut 30% of Earths surface is land, including continents and islands. Land makes up an area of the earth called the lithosphere.

The oxygen we breathe is a part of the earths atmosphere, a layer of all kinds of gasses that span about 6,000 miles above the earths surface. Our atmosphere is composed of 78% Nitrogen, 21% oxygen small amounts of argon and other gases.


Landforms are the natural features of the earths surface. Four of the major landforms are Mountains, Hills, Plateaus, and plains. others are valleys, canyons, and basins. the landforms often contain lakes, rivers, and streams.

Earths Heights and Dephts

Great contrasts exist in the depths and heights of earths surface. The highest point on earth is at the top of Mount Everest, which is 29,035 feet above sea level. the lowest land point on dry land is at 1,349 feet below sea level is the shore of the Dead sea in southwest Asia. The deepest depression known to us lies beneath the pacific ocean southwest of Guam in the Mariana Trench, a long, narrow underwater canyon about 35,827 feet deep! these and other natural features have developed as the earth has changed over millions of years.