Where does Google Earth imagery come from?

google gets its imagery from a variety of sources such as commercial satellite providers such as DigitalGlobe and GeoEye as well as from government and local agencies. Once the imagery is acquired by google, it next has to be processed into the format and coordinate system of google Earth's databases. Then it goes through a quality control process and processing system before getting distributed to the google Earth database servers. This is one reason you usually do not find any imagery newer than about 6 months in google Earth.