Satellite Motion

Communication: Satellites enable global communication by transmitting signals for television, radio, internet, and phone services across vast distances.

Weather Forecasting: Satellites monitor weather patterns, track storms, and gather data to predict weather conditions and natural disasters.

GPS and Navigation: Satellites provide precise location and timing information, essential for navigation systems in cars, airplanes, and smartphones.

Satellite - smaller body revolving around a larger body

Teacher Domain Discussion Questions

Why doesn't the Moon hit Earth even though it is "falling" toward it?

What would happen if the Moon moved faster than it does now?

How is the Sun able to have so many planetary bodies in orbit around it?

Why do planets closer to the Sun than Earth not fall into the Sun from the pull of gravity?

If someone asked you if it's true that the Moon is always falling towards the Earth, what would you tell them?

See where the earth's satellites are right now! Satellite Tracker3D

Click this link and wait until the program jumps to the screen.

1. To send an artificial satellite into circular orbit around earth it must first achieve a speed of 7900 m/s.

If greater than 7900 m/s, the satellite has an elliptical orbit.

If velocity is greater than 11 km/s then the satellite leaves earth's orbit (called escape velocity).

2. Air resistance slows down satellites and eventually causes them to spiral back to earth.

1. When a satellite orbits in time with earth's rotation it is called geosynchronous.

2. Time for one revolution - 24 hrs

3. A satellite at distance of 6 earth radii from earth's center will orbit earth every 24 hrs.

4. Since both satellite and earth move together, it always remains directly above the same spot above earth's equator.

"On Earth, impact craters are harder to recognize because of weathering and erosion of its surface. The Moon lacks water, an atmosphere, and tectonic activity, three forces that erode Earth's surface and erase all but the most recent impacts. Approximately 80% of Earth's surface is less than 200 million years old, while over 99% of the Moon's surface is more than 3 billion years old. Essentially, the Moon's surface has not been modified since early in its history, so most of its craters are still visible."