教学ppt课件 lesson 54 satellites.pptVIP

Lesson 54 Satellites What was carried up into space on Oct. 15th, 2003? Shen Zhou Ⅴ Shen Zhou Man-made A speed of… Equipment Sun panels unfold In a high circle Weather satellites What is a satellite? A satellite is an object, either natural or man-made, which travels in an orbit round another object in space. 1.Why is it possible for satellites to go into space? 2. Why are satellites so expensive? 3. How does a satellite produce electricity? 4. What can satellites send back to the earth? 5.Why don’t most broadcasting satellites change their positions? 1. Why is it possible for satellites to go into space? Because when the speed of a rocket that carries a satellite up into space reaches 28,440 km/h, it can escape the pull of the earth. 2. Why are satellites so expensive? Because it has to be light and it has expensive equipment: cameras, etc. 3. How does a satellite produce electricity? A satellite produces electricity by using very broad sun panels. 4. What can satellites send back to the earth? Radio and TV programmes; signals; information and photos of weather conditions. 5. Why don’t most broadcasting satellites change their positions? Because only in this way, they are able to connect broadcasting stations which are a long distance from each other. Note making WHAT SATELLITES CAN DO TYPES OF SATELLITES TYPES OF SATELLITES Broadcasting satellites Weather satellites Communications satellites Space satellites WHAT SATELLITES CAN DO Make electricity Take photos Change direction Receive and send signals Collect and send information Carry out experiments Information on satellites and man-made satellites Definition(定义） Types Natural satellites of the earth An object, either natural or man-made, which travels in an orbit round another object in space, is called a satellite. Natural satellites;Man-made satellites The moon.It travels round the earth once every month. Something about the man-made satellites How…carried up into space? Speed to escape the pul