During the first decade of the 2000s, superhero films abounded, as did earthbound science fiction such as the "Matrix" trilogy. In 2005, the "Star Wars" saga was completed (although it was later continued, but at the time it was not intended to be) with the darkly themed '. Science-fiction also returned as a tool for political commentary in films such as "A.I. Artificial Intelligence", "Minority Report", "Sunshine", "District 9", "Children of Men", "Serenity", "Sleep Dealer", and "Pandorum". The 2000s also saw the release of "Transformers" (2007) and ' (2009), both of which resulted in worldwide box office success. In 2009, James Cameron's "Avatar" garnered worldwide box office success, and would later become the highest-grossing movie of all time. This movie was also an example of political commentary. It depicted humans destroying the environment on another planet by mining for a special metal called unobtainium. That same year, "Terminator Salvation" was released and garnered only moderate success.