8 - 26 Motion in the universe
Gravitational force
● Gravitational field strength varies (different on other suns/planets/satellites), as
depends on sun/planet/satellite’s mass
● ***Greater masses of objects, stronger attractive forces between them
● ***Distance between masses ↑, forces between them ↓
●
1
, ●
● ***Gravitational force causes......
○ Moons orbiting planets
○ Planets + comets orbiting suns
○ Artificial satellites orbiting Earth
Satellites and moons
● ***Satellites orbit planets
● Natural satellites are called moons
● Artificial satellites orbit Earth, high orbit for communication over large distances,
international phone calls/video links, internet etc.; low orbit for monitor in detail
the Earth’s surface, e.g.: temperature of oceans, progress of forest fires
2
Gravitational force
● Gravitational field strength varies (different on other suns/planets/satellites), as
depends on sun/planet/satellite’s mass
● ***Greater masses of objects, stronger attractive forces between them
● ***Distance between masses ↑, forces between them ↓
●
1
, ●
● ***Gravitational force causes......
○ Moons orbiting planets
○ Planets + comets orbiting suns
○ Artificial satellites orbiting Earth
Satellites and moons
● ***Satellites orbit planets
● Natural satellites are called moons
● Artificial satellites orbit Earth, high orbit for communication over large distances,
international phone calls/video links, internet etc.; low orbit for monitor in detail
the Earth’s surface, e.g.: temperature of oceans, progress of forest fires
2
