The Earth in Space

Chapter 1, Section 2Pages 29 - 32

The Solar System

• Solar System- Earth, seven other planets, and thousands of smaller bodies that revolve around the Sun.

• Orbit- path that a body in the solar system travels around the sun.

Earthlike Planets

• Mercury, Venus, Mars, and Pluto.

• Solid and small.

• Few or no moons.

• Rotate, or spin, slowly.

Non-Earthlike Planets• Jupiter, Saturn, Neptune,

and Uranus.

• Very large.

• Balls of gas.

• Spin rapidly and have many moons.

• Rings of rock and dust.

Sun, Earth, and Moon• Sun is 93 million miles from

earth.

• Atmosphere- the layer of air surrounding the Earth.

• Atmosphere holds oxygen and nitrogen.

• Atmosphere also keeps in suns heat and reflects sun’s bad rays.

• Moon is Earth’s nearest neighbor.

Earth’s Movement• Axis- an imaginary line that runs

through the earth’s center between the North and South poles.

• Earth takes 24 hours to finish one complete spin on its axis.

• Revolution- complete orbit around the sun every 365 ¼ days.

• Leap Year- a year that contains an extra day.

The Earth is tilted 23 ½ degrees on its axis.

Earth’s Seasons

Solstices and Equinoxes• Summer Solstice- the day with

the most hours of sunlight and fewest hours of darkness. - June 21st

• Winter Solstice- the day with the fewest hours of sunlight. - December 22nd

• Equinoxes- when day and night are equal length in both hemispheres. – March 21st or September 23rd