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.