Happy Space Day! To celebrate today’s enormous theme, TED-Ed invites you on on a sprawling adventure into the great unknown. What’s the deal with our universe? What’s going on out there? And is anybody home? We may have more questions than answers, but these five lessons will surely ignite your curiosity about the immense, wondrous cosmos we call home.

Let’s begin at the beginning. The very, very beginning. How did the universe begin — and how is it expanding? CERN physicist Tom Whyntie shows how cosmologists and particle physicists explore these questions by replicating the heat, energy, and activity of the first few seconds of our universe, right after the Big Bang.

Moving a little closer to home, we ask — where in the world is Earth actually located? If we aren’t at the center of the universe, then what is? Marjee Chmiel and Trevor Owens discuss where we stand in the (very) big scheme of things.

What would it be like to actually explore the cosmos firsthand? As commander of Skylab, astronaut Jerry Carr spent over 2,000 hours in space, orbiting the Earth over 1,000 times. Recounting his life story, Carr remembers the enchanting years he spent at NASA (and check out Jay Buckey’s lesson for what astronauts like Jerry could expect to happen to their body during these huge changes in gravity).

We can’t take a trip into space, of course, without addressing that elephant in the room: aliens. Could there be intelligent life on other planets? This question has piqued imagination and curiosity for decades. Jill Tarter explores the answer with the Drake Equation — a mathematical formula that calculates the possibility of undiscovered life.

Despite our short time here on Earth, the universe will go on and on. Well…until one day in the very distant future. We know that all stars will eventually burn out into a cold nothingness. Renée Hlozek expands on the beauty of this dark ending.

To find out what makes up most of our universe, how we’ll go about finding Earth-like planets, whether or not space is really out to get us, or the ins and outs of the international space race, look no further than the series Out of This World. Have we left out an important lesson on space? Nominate an educator and lesson idea here.