I enjoy numbers... So lets see how many photographs one would have to take of every square yard of land on this wonderful blue sphere we call earth... and for extra credit quickly figure out how long it will take... so lets do a little simple math...
There are approximately 57.5 million square miles of land on earth, only 29.2 percent of the earth's surface.
Lets assume my Canon EOS 60D with a macro wide lens takes a perfectly square yard with each 18 meg photo resulting in a 5meg compressed image file.
There are 3,097,600 square yards in a square mile.
So that results in having to take 178,112,000,000,000 photos to capture every square yard of land of earth
My disk storage to hold all those photos needs to be at least 890,560,000,000,000,000,000 bytes large... 890 Sextillion...
Off topic, this random number is almost the exact number of G forces of the Wakefield plasma accelerator 890,000,000,000,000,000,000Gs... source
Or even more bizarre this number is also close to the number of photons from cell phone "
Ok getting back to photos.... If it takes 60 seconds (i.e.1 minute) to take each photo.. so that 525,600 photos can be taken per year. or it will take an incredible 338,873,668 years to complete the task. That over 338 million years!
Or from a balloon capturing every sq mile with one per minute to take each photo would still take 109 years to complete.