By Brad Friedman on 5/12/2013, 8:48pm PT  

As posted by NASA's Astronomy Picture of the Day, which explains the above as follows:

What are these humans doing? Dancing. Many humans on Earth exhibit periods of happiness, and one method of displaying happiness is dancing. Happiness and dancing transcend political boundaries and occur in practically every human society. Above, Matt Harding traveled through many nations on Earth, planned on dancing, and filmed the result. The above video, the latest in a series of similar videos, is perhaps a dramatic example that humans from all over planet Earth feel a common bond as part of a single species. Happiness is frequently contagious --- few people are able to watch the above video without smiling.

[Hat-tip and Happy Mothers Day to BRAD BLOG reader CA.]