© Shutterstock/The Daily Galaxy - Great Discoveries ChannelUnexplained Encounters During Training MissionsCraft That Travel Between Air And SeaFour Major Incidents Still UnexplainedThis New U.S. Law Could Expose Alien Technology"We're at a unique moment in history. People have access to tools that can reveal things. The momentum is building." "Maybe they lived here for a long time, before we even evolved, and sought safety from the Earth's atmospheric and geologic cataclysms by creating a habitat or place to live beneath the seafloor... That's one hypothesis."