After Hours

Desktop Wallpaper: The Blue Marble known as Earth

The Blue Marble from Apollo 17

The Blue Marble from Apollo 17 taken in 1972. I have used this image as my Desktop Wallpaper many times.

Courtesy NASA Johnson Space Center - Credit: NASA


Mark W. Kaelin has been writing and editing stories about the IT industry, gadgets, finance, accounting, and tech-life for more than 25 years. Most recently, he has been a regular contributor to,, and TechRepublic.