The World of Satellites
What do you know about Satellites?
With the term Satellite we indicate every celestial and natural body or object that moves in the outer space, orbiting around a planet or a body different from the stars.
In our Solar System there are more than one hundred and fifty natural satellites: it’s obvious that there are various satellites around other stars planets that we don’t know.
Generally, the giant gases have extensive satellites, while the terrestrial planets systems have just a few of these celestial bodies: for instance, in our Solar System Mercury and Venus don’t have any satellites, while the Earth has a very big satellite (comparing it to its own size) named Moon.
Furthermore, Mars possesses two small satellites, named Phobos and Deimos.
We have made a brief presentation of natural satellites. But it is important to explain that there are also artifical satellites.
In fact, nowadays it is very common to use the term satellite to indicate an instrument made by man sent into orbit around the Earth to accomplish certain functions and useful services.
For instance: Internet and telephone communications, GPS positioning and photos to study the weather changes, which can be useful for certain scientific researches.