We finally start the tale of Earth’s history from the beginning, in the cold depths of outer space. The Sun is born and the first asteroids assemble. When these asteroids crash into Earth today, they provide time capsules from the beginning of the solar system.

Extra credit: look for the Orion Nebula in the night sky, or go meteorite hunting with a friend.

How did Earth grow from ant-size to, well… Earth-size? What perils did it face along the way? And how was the early Earth like a fine vinaigrette?

Extra credit: try to freeze a mixture of oil and vinegar before they separate.

Today, we'll learn how deep humans have traveled into the planet, and how we know what's even deeper down. We'll meet mineral oozes, coils of liquid iron, and a Danish woman from the 1930s who discovered the center of the Earth.

Extra credit: Make a tin-can telephone, find an inductor in one of your electric appliances, or look for an aurora.

Earth's first oceans were hundreds of times deeper than the Pacific and made of molten rock. Where did they come from, where did they go? What stuff was in them, how do we know? Today, let's dive in and see how these oceans turned into today's mantle.

Extra credit: Drink a glass of ice water, watch The Core (2003), or see if you can find a garnet in your home or a museum.

Our Moon is unlike any other in the solar system, and the story of its' birth is truly extraordinary. This episode, we'll weigh the evidence for various Moon origin stories alongside Neil Armstrong, George Darwin, and more recent scientists. In the end, truth is stranger than fiction.

Extra credit: Take some time for yourself and have a good long look at the moon.

The Earth of 4.5 billion years ago was perhaps the most alien version of our world, thanks to a collision with a rogue planet. Days and nights were six times shorter, the newborn Moon was as close as a weather satellite, and everything was covered with a sea of magma. Today, we learn how the Moon transformed from a giant Eye of Sauron into our pale nighttime companion.

Extra credit: Squeeze a stress ball, eat only one color of candy, and try to solve this week's hidden word puzzle.

What is the oldest thing on our planet? How old is it, and where was it found?

Today, we tell the story of a worldwide, decades-long hunt for a single grain of sand. We'll journey to underground magma chambers, the sun-baked Australian Outback, and the lair of a giant shrimp.

Extra credit: Let a handful of sand run through your fingers, or go pressure-wash something.

The idea of plate tectonics is the cornerstone of modern geology.

But it wasn't always that way, and it wasn't an easy idea to sell. Today, we'll meet two scientists who faced ridicule for proposing continental drift: a German climatologist and an American cartographer, the greatest of her generation. We'll also meet a lost expedition to Greenland, the Mid-Atlantic Ridge, and Jacques Cousteau.

Extra credit: Look at maps of the ocean floor, or try to align the continents in various patterns on a map.

How is new crust made, and why isn't the Earth constantly expanding like a party balloon? To answer these questions, we'll track the life, death, and rebirth of Earth's surface. Stops along the way include the Mid-Atlantic Ridge, a prize-fight between tectonic plates beneath New Zealand, and a stop for dessert on the Italian island of Vulcano.

Extra credit: Experiment with your carpets at home, pushing them together and testing which one sinks beneath the other.

When did Earth's crust form?

It's easy to take the ground beneath our feet for granted, but the story of our crust's origins is one of the most hotly debated topics in Earth history. Today, we'll learn about how elements inside zircon crystals can help solve this mystery. In fact, the element hafnium was discovered inside a zircon by two researchers who also helped keep gold and scientists out of German hands in World War II.

Extra credit: Look at table salt under a microscope, or find different colors of quartz in your local mineral collections.

How did water arrive on planet Earth?

Today, we learn just how much water Earth has (spoiler: probably not as much as you'd think), and where it came from in the first place. We'll take a joyride around the early solar system, learn how our stellar neighborhood is like a snow-capped mountain, and discover how the planet Jupiter might have played a crucial role in creating the oceans of Earth.

Extra credit: Drink some water, make a snowball, or watch the Kevin Costner classic Waterworld.

How do we know when the first oceans existed?

Water leaves its' fingerprints over every surface of Earth, even in the oldest, toughest crystals. Today, we'll take an imaginary ride through the earliest oceans, examine how water slowly transforms everything it touches, and how these changes are recorded in the Jack Hills zircons, 4.4 billion years ago.

Extra Credit: Make an underwater rock garden, walk into a muddy beach, or visit a dog park.

When did life arise on planet Earth?

Today, we look at the search for biological remains in the oldest minerals on Earth, the Jack Hills zircons of Western Australia, 4.4-4.0 billion years ago. We learn why carbon is an excellent building block for life, how to turn that carbon into diamonds and graphite, and why it's very hard to find conclusive fossils in very old rocks.

Extra credit: Try to find all the things in your house that have carbon in them. Bonus points if you can find graphite or diamonds.

When did life begin on planet Earth?

That's a big question to tackle, one that will take a few episodes to answer. Today, we start this new arc by introducing three key ingredients of life: proteins, carbohydrates, and fats. These three molecules can be found in the food we eat, our own bodies, and as we'll see in future episodes, in the voids between stars.

Extra credit: Keep tabs on which foods you eat have more carbs, proteins, or fats. Make yourself a dish that has all three ingredients.

How were life’s ingredients assembled billions of years ago?

Today, we journey to the deepest reaches of space to take the first steps from non-living molecules towards life. On the way, we learn what it really means to be organic, how to break a rainbow, and what space smells like.

Extra credit: Separate light using a prism, or cook a steak.

How did the ingredients of life arrive on Earth?

Today, we look at how asteroids brought organic material from the depths of space to Earth's surface. On the way, we'll run into an old friend from Episode 4, meet an ancient Greek astronomer, and search for aliens hidden in Antarctic ice.

Extra credit: Eat something with glutamic acid in it- meat, mushrooms, or soy sauce. Extra extra credit if you can have all three at once.

How did the Earth transform simple carbon into the complex ingredients of life?

Today, we'll meet a troubled Charles Darwin hunting for fossils, we'll create slime from thin air in one of the greatest laboratory experiments, and we'll learn what was in Earth's earliest atmosphere.

Extra Credit: Breathe in, breathe out, and have a sip of your favorite soup.

When did DNA show up in Earth's past, and how does it actually work today?

In this episode, we brush up on biology, learning about DNA's hardworking but underrated sister RNA, how cells turn genetic code into meat, and inch closer to actual living things in the Hadean.

Extra Credit: Help someone make a tasty dish in the kitchen today, or thank someone you think doesn't get enough credit for their work.

How and where did the first cells form on planet Earth, 4 billion years ago?

To answer that question, we investigate why oil and water hate each other, explore the seafloor with the Titanic's discoverer, and take a relaxing dip inside a hot spring.

Extra credit: drop some olive oil into water, or make a trip to the closest hot spring in your local area.

Season 1 Finale.

What was the first living thing on Earth, when did it live, and what did it do?

Today, we end Season 1 by meeting LUCA, the oldest ancestor for every living thing on Earth today. On the way, we'll tackle how complex life formed in a chaotic universe and why it hasn't formed again, take a trip down life's family tree, and meet a deadly modern microbe- one of the closest relatives of the oldest living thing.

Thank you all for listening to Season 1, and stay tuned for Season 2!

Extra Credit: Take a look at family photos, or check your canned foods for botulism.