There are an estimated 70 billion, trillion stars out there in the visible universe. Many are surrounded by planets, and some might be suitable for habitable life. A small percentage of these worlds might have existed and been habitable long before Earth, but in the context of the universe, this small percentage still represents millions, probably billions of places where advanced life may have sprung forth.Well, that’s a super depressing way to start a video! Sadly, this will be the case for the majority of civilizations out there in the universe that is older than humanity. Earth-based life has had its fair share of good fortune over the past few billion years, with the planets literally aligning in our favor to protect us from cosmic dangers. The Great Filter is a hypothesis which seeks to explain why mankind is yet to meet an advanced civilization. If advanced civilizations were present billions of years before us, then it’s possible that they lived long enough to leave some form of mark on the universe.