There are 24 satellites in the United States GPS system that are active. There are 6 more that are "asleep" and saving power until they are activated to replace one of the 24 satellites that has to be taken off line for maintenance, damage, and so forth.
The Russians also have roughly that number of satellites in their GLONASS system.
Europe is deploying satellites in its Galileo positioning system.
Japan has or will launch its first satellite in its QTZZ positiong system.
There are also about 4 satellites in WAAS, the Wide Area Augmentation System that makes GPS more accurate. Europe's version of this is EGNOS, or European Geostationary Overlay Service. It has 4 or 5 satellites.
Three.
Update: For communication, geostationary satellites can only 'see' to +/- 75 degrees of latitude. Another type of satellite would be required to see the caps.
Three
It uses 66 small satellites in low earth orbit
Please be a little more precise in your meaning when you say "cover" the Earth. For radio or TV communications, three satellites in geosynchronous orbit will be visible from any inhabitable locale on the planet. (The polar regions aren't really "inhabitable", and aren't visible from GEO. ) For navigational purposes, more are required. The GPS system requires line-of-site to FOUR satellites at one time in order to give a good "fix" of your position; the USAF uses 27 satellites to accomplish this, anywhere on the Earth.
There are hundreds. If that seems like "many" to you, then the answer is 'yes'.
Earth's Moon has no satellites of its own. While it might be possible, I am not aware of any moons that have natural satellites of their own.
Every GPS unit needs a minimum of four (4) satellites to compute a 3-dimensional position, and performs more accurate calculations with more satellites. I think my TomTom is capable of using 12 simultaneous satellites if it can see that many. Yours may be different.
You need 4 to locate a position. There are 24 satellites in use in the sky with 8 spares.
It takes at least 3 satellites.
2,217
It uses 66 small satellites in low earth orbit
Satellites cannot orbit the US; they orbit the Earth, and there are several thousand of them.
Ganymede Jupiter's moon has 6 satellites in total from the north Pole on the Earth.
A satellite of earth that is not man made is the moon. There are many satellites that are man made that orbit the earth. These satellites are used for communication between Internet and television viewing.
The planet Earth upon which we live has precisely one natural satellite, which is known as the moon, or Luna, and it has a great many artificial satellites, including the International Space Station, communication satellites, surveillance satellites, global positioning satellites, etc.
10
Around 6000
yes
2465 artificial satellites orbiting the Earth