11.1 Days and Night
1.Scientists who study space = astronomers
2.The brightest star in the night sky seem to form patterns, called constellations.
3.The Sun rises from the east and travel through the sky, after that sets to the west.
4.The Earth axis is the line joining the North Pole to the South Pole.
5.The Sun appears to move across the sky from east to west can happens because of the Earth is turning from West to East.
6.The Earth takes one year to obit around the Sun.
7.The Earth is one of eight planets in our solar system.
8.The planets do not drift into space because of the pulling force of the Sun's gravity.
9.The Sun, all the orbiting planets and their moons make up the solar system.
10.The four planets closet to the Sun are called rocky planets.
11.The four planets further from the Sun are called gas giants.
12.The Sun and all the stars are sources of light.
13.When sunlight reaches a planet, it reflects off the planet and the light reaches our eyes.
14.The full moon is when the Moon's face is a complete circle.
15.The new moon is when the Moon's face is a completely dark.
16.The Moon to change from full moon to new moon takes about two weeks.
17.The Moon orbits around the Earth and it takes about one month to complete an obit.
18.Copernicus suggested that the Earth and all planets travel around the Sun and it is called heliocentric model.
19.A galaxy is made up of many billions of stars.
20.There is an enormous number of stars in the Universe.
21.To get into space , we have to travel above the Earth's atmosphere.
22.A spacecraft must be equipped with supply of oxygen so that astronaut on board can breath.
23.Giant rockets are needed to push the spacecraft upward.
24.The Moon's gravity is much weaker than the earth.
25.The Moon has no atmosphere and no air resistance.