Watch Horses on Mars (2001) HD Full Movie Free on solarmovie.do. Watch Horses on Mars (2001) online free. Some 3.6 billion years ago, two microbes are playing "king of the pebble" when an event occurs that ...Some 3.6 billion years ago, two microbes are playing "king of the pebble" when an event occurs that will separate them and change their future forever. This is the story of the microbe that remains on that pebble, and his amazing journey through time and space.