Theory has it that Planet X was once part of our solar system and that a cataclysmic event split it into two pieces, creating Earth and Mars. This might be one explanation for Earth's similarity to Mars. It might also explain how UFOs have influenced Earth throughout history. Many religious beliefs, legends, images, icons and myths show remarkable similarities across cultures, bridging time and space, suggesting aliens (or are they actually our true ancestors?) have had a profound impact on our planet.