What are Satellites?  Artificial satellites are objects built and sent into Earth’s orbit by humans  A “natural” satellite is a small body that orbits a larger body, i.e. a moon orbiting a planet  Satellites help us communicate, observe, forecast weather, predict magnetic storms, watch TV, make long-distance phone calls and even find our location on the planet

How Do Satellites Work?

Communication Satellites  Before communication satellites, cable connections needed to physically reach from one person to another  Setting up telephones across an ocean meant laying submarine cables along the ocean floor!  Today, satellites use digital systems which allow clearer transmissions and a greater number of users at one time  Every nation in the world has gone “wireless”

Observation and Research Satellites  Weather satellites are designed to stay in one position about Earth  This is called geosynchronous orbit  The result is 24 hour a day weather conditions  Two Canadian satellites, LANDSAT and RADARSAT, have been used to follow ships at sea, monitor soil quality, track forest fires, report on environmental change, and search for natural resources

Remote Sensing Satellites  The main purpose of satellites in low Earth orbit (200 too 1000km altitude) is to carry out remote sensing.  This is a process in which imaging devices in a satellite make observations of Earth’s surface and send this information back to Earth.  This is used for monitoring the condition of Earth, natural resources, and effects of urbanization.  This information is used for planning.

Satellites as Personal Tracking Devices  The Global Positioning System (GPS) lets you know your position accurate to within a few meters.  Twenty-four GPS satellites are in orbit around Earth, which means that at least three are above any given location in the world at any time.  Radio signals from the satellites are picked up by a hand-held receiver – which then creates a digital display

When Space Age Technology Helps Us  Go to pg. 431 – write down five space technologies and how they led to new uses on Earth:  Example: Designing electronics for Hubble Space Telescope = Led to digital imaging detection & treatment of breast cancer

Section 1 and 2 Review  Pg. 406 #2-10,  Pg. 433 #1-8