This is not animation, it is data visualization. The movie depicts flight patterns that occurred over a few days in 2005 March. There's a higher resolution version at http://antwrp.gsfc.nasa.gov/apod/ap080429.html that clearly shows a count on the lower left of the number of USA-related flights at the time of day listed on the lower right. The trails shown are not contrails but rather generated artificially by a computer algorithm. Major cities in North America and the USA are discernable.