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.