Life is tenacious and the universe is vast, so some are confident that extraterrestrial life is hiding out there. These worlds are the top contenders.

There are 8 planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Naptune. The solar system formed about 4.6 billion years ago from a cloud of interstellar gas and dust.

Full of extraordinary footage, Robert Stone's blissed-out mind-bender of a movie meditates on the possibilities of life in ...