Lunar Reconnaissance Orbiter comes to the mind first. It's NASA spacecraft which takes images of the lunar surface from about 50 km height. And GRAIL pair of satellites will (or maybe already are) study the interior composition of Moon by measuring it's gravitational field.
Probably there are others which i don't know about.
There are two types of satellites that are located in a foxed spot over earth the first is reconnaissance satellites for observation of earth and usually used by the military.. The second is earth observation satellites and are intended for environmental monitoring
The Global Positioning System (GPS) currently consists of a constellation of 31 operational satellites. These satellites are spread out in six orbital planes, approximately 20,200 kilometers above the Earth's surface.
Mapping satellites.
satellites
Satellites are monitoring our planet on a second-by-second basis. Many of them are on 'scientific' missions - specifically monitoring the planet's surface for sudden changes. Any shift in the Earth's tectonic plates can be detected - and warnings given to allow people to flee to safety.
Most communications satellites operate outside of the earth's atmosphere. The GPS satellites are about 23,000 miles from the surface of the earth.
Actually only 3 geostationary satellites are enough to cover the earth.
remote sensing satellites develop highly detailed and accurate maps on earths surface.
because they are used!! dahhh!! lol ;)
- No ...
satellites
Go do your homework.