1. Satellite Motion Kepler’s law

2. Satellite Motion A satellite is often thought of as being a projectile which is orbiting the Earth. 1.How can a projectile orbit the Earth? Doesn't a projectile accelerate towards the Earth under the influence of gravity? 2.And as such, wouldn't any projectile ultimately fall towards the Earth and collide with the Earth, thus ceasing its orbit?

3. A satellite is any object that is orbiting the earth, sun or other massive body. Satellites can be categorized as natural satellites or man-made satellites.

4. Elliptical Orbits of Satellites Satellites will orbit in paths that can be described as ellipses. In such cases, the central body is located at one of the foci of the ellipse.

5. In summary, satellites are projectiles that orbit around a central massive body instead of falling into it. Being projectiles, they are acted upon by the force of gravity - a universal force that acts over even large distances between any two masses.

6. The Laws of Ellipses-Kepler’s laws Kepler's first law is all planets orbit the sun in a path that resembles an ellipse, with the sun being located at one of the foci of that ellipse

7. The Laws of Ellipses-Kepler’s laws The second law states that a planet sweeps out equal areas in equal times. In a highly elliptical orbit, the long, thin area is equal to the broad, fan-shaped area. The Law of Equal Areas

8. The Law of Ellipses-Kepler’s law Kepler's third law - the law of harmonies Unlike Kepler's first and second laws that describe the motion characteristics of a single planet, the third law makes a comparison between the motion characteristics of different planets.  Kepler’s third law is that the ratio of the squares of the periods to the cubes of their average distances from the sun is the same for every one of the planets.

9. Planet Period (s) Average Distance (m) T 2 /R 3 (s 2 /m 3 ) Earth3.156 x 10 7 s1.4957 x 10 11 2.977 x 10 -19 Mars5.93 x 10 7 s2.278 x 10 11 2.975 x 10 -19 Kepler’s third Law equation

10. These plots represent three possible mathematical relationships between period of revolution, T and mean distance from the Sun, r.