Sci. 5-2 Artificial Satellites Pages 132-135

A. Artificial Satellites- any human-made object placed in orbit around a body in space, such as Earth.

B. The Soviet Union launched the first Earth-orbiting satellite in 1957.

1) Sputnik 1- carried instruments to measure the properties of Earth’s upper atmosphere

2) Sputnik 2- carried a dog named Laika

C. The first United States satellite went up in 1958.

1) Explorer 1- carried scientific instruments to measure cosmic rays and small dust particles.

a) discovered the Van Allen radiation belts around Earth.

2) Tiros 1- weather satellite

3) Echo 1- 1st communications satellite

D. Low Earth Orbit (LEO’s) are located a few hundred kilometers above the Earth’s surface. ( Still in Earth’s atmosphere)

E. Satellites in geosynchronous orbits (GEO’s) have an orbit period of 24 hrs and remain over one spot.

1) This allows ground stations to be in continuous contact with these satellites so your TV program or phone call is not interrupted.

F. Using satellites, scientists have been able to obtain information by remote-sensing – gathering images and data from high above the Earth’s surface.

G. Satellite programs are used for weather observations, communications, mapping the Earth, tracking ocean currents, crop growth and urban development.

H. Military Satellites are used to spy on other countries to see their military strength and to serve as early warning systems against missiles launched toward the USA.