In the context of spaceflight a satellite is an object that has been intentionally placed into orbit these objects are called artificial satellites to distinguish them from natural satellites such as earth s moon.
What can satellites do.
Satellites differ greatly in the level of detail they can see.
Like every other machine satellites do not last.
Data acquired by satellite borne radars were able to show sea levels have been rising by three mm a year over the last decade.
Two things can happen to old satellites.
Imaging satellites can measure the changing sizes of glaciers which is difficult to do from the ground due to the remoteness and darkness of the polar regions.
Artificial satellites can be sent to orbit other planets too.
Why can t noaa s satellites see someone s house.
For the closer satellites engineers will use its last bit of fuel to slow it down so it will fall out of orbit and burn up in the atmosphere.
Because instead of close up high resolution images our polar orbiting satellites provide much more frequent coverage twice daily over the whole planet in order to understand global weather patterns.
Further satellites are instead sent even farther away from earth.
For example there are currently satellites orbiting the moon the sun and several other planets including mercury venus mars and saturn.
The soviet union launched the first artificial satellite sputnik 1 on october 4 1957.