(from the Washington Post's list of 40 Maps that Explain the World)

This NASA moving image, recorded by satellite over a full year as part of their Blue Marble Project, shows the ebb and flow of the seasons and vegetation. Both are absolutely crucial factors in every facet of human existence — so crucial we barely even think about them. It’s also a reminder that the Earth is, for all its political and social and religious divisions, still unified by the natural phenomena that make everything else possible.

(from: http://www.washingtonpost.com/blogs/worldviews/wp/2013/08/12/40-maps-that-explain-the-world/)