T H E E A RT HI N S I D E A N D O U T

CHAPTER 2 SECTION 1

I. Earth

A. The earth is the only habitable planet in the sun’s solar system.

B. The drifting of the continents shaped the world we live in today.

C. Continental Puzzle1. The seven continents on earth fit together

like a jigsaw puzzle. 2. Continents—landmasses above water on

Earth. 3. Francis Bacon (1620) first to suggest 7

continents were once one.

II. The Solar SystemA. The Earth’s Neighborhood

1. Earth is third planet in the solar system of the sun.

2. Sun is medium-sized star at edge of the Milky Way galaxy.

3. The solar system includes:a. sun and nine known planets. b. comets—icy spheres orbiting the sun.c. asteroids—large chunks of rocky

material orbiting the sun.

III.The Structure of the EarthA. Matters of Size

1. Circumference of the earth: about 24,900 miles.

2. Diameter of the earth: about 7,900 miles.

B. Inside the Earth 1. The core is the center of the earth; made

up of iron, nickel.2. Outer core is liquid; inner core is solid.3. The mantle surrounds the core:

a. has several layers.b. contains most of Earth’s mass.

C. Inside the Earth 1. Magma—molten rock that forms in the mantle. 2. Crust—thin layer of rock at Earth’s surface.

D. On and Above the Earth 1. Atmosphere is the layer of gasses surrounding the

earth: a. contains oxygen.b. protects Earth from radiation, space debris.c. is the medium for weather and climate.

E. On and Above the Earth 1. Lithosphere—solid rock portion of Earth’s

surface, forms ocean floor. 2. Hydrosphere—water elements on Earth

including atmospheric water.3. Biosphere—atmosphere, lithosphere,

hydrosphere combined. a. Plants and animals live within biosphere.

F. Continental Drift 1. Continental Drift—1912 hypothesis of

Alfred Wegener: 2. Earth once one supercontinent; Wegener

calls it Pangaea, “all earth.” 3. Pangaea splits into many plates that

slowly drift apart.