every 6 months, to keep things more updated, it used to be every 12 months.by: Dr. michaelson (retired scientist)
they take photos every day, every hour. what you want to know is when will they have new ones published, and that depends on the people that own them.
With a camera!!
Really depends on the source of the satellite imagery. Google for examples purchases or leases its satellite imagery from a number of imagery providers such as GeoEye and DigitalGlobe. Google updates...
With cheese