Astronomy

Planet - Any of the nine large heavenly bodies revolving around the sun and shining by reflected light in the order of proximity to the sun.

Star -  Any of the planets, except the moon, appearing as fixed points in the night sky.

Gravity - The force of attraction between masses.

Galaxy - Large system of stars held together by gravitation and isolated from similar systems by vast regions at space.

Milky Way Galaxy - Galaxy that contains the solar system.

Universe - Millions of galaxies

 Mass - A body of coherent matter.

Weight - The amount of quanitity of heaviness or mass.

Natural satellite - is already made by nature e.g. moon.

Artificial satellite - is a man-made satellite.

Geostationary orbit - stays above same point on earth.

Polar orbit -  a orbit that passes over the poles of the earth.

Comet - Streams away from the sun leaving a trail of dust behind and gas.  It moves about the sun.

·         Gravity is an attractive force that acts between all objects that has mass.  The size of the force depends on the mass of the object.

·         The force of gravity between two objects depends on the mass of the objects and also the distance between them.

·         The greater the distance between the masses, the weaker the pull would be.

A satellite is any object that orbits another object.  It is kept in orbit by gravity.  The gravitational field strength…