How can rocks tell us the stories of ancient Earth- stories of magma, water, and life? To answer that question, we look at a few common rock types and examine how they formed.

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.

My guest today is Dr. Joti Rouillard, a research fellow at the University of Science and Technology in Hefei, China. Dr. Rouillard talks about his research on the earliest fossils on Earth, microscopic bacteria 3.5 billion years old. It turns out, identifying a fossil bacteria is extremely difficult since they resemble other tiny non-living objects. We also talk about working in the Australian Outback, kangaroo encounters, and what happens when you mix alcohol and rocks.

Dr. Rouillard's email: joti.rouillard@gmail.com

Miniseries Episode 2

Australia is one of the top destinations for people who love the ancient Earth. Today, we take a brief tour around the three oldest regions in Australia: the Yilgarn Craton near Perth, the Pilbara Craton near Port Hedland, and the Gawler Craton near Adelaide. On the way, we'll meet the oldest minerals, the oldest fossils, and learn the connection between ancient bacteria and modern steel.

Miniseries Episode 3

Africa is a continent with many different nations and rocks. Today, we learn how most of Africa was fused together billions of years ago, and which pockets preserve the best evidence for ancient life (South Africa, Zimbabwe). Along the way, we'll meet the richest human in history, a giant knife made from magma, and a two-billion-year family reunion.

Miniseries Episode 4:

South America has impressive geology, but most of its' ancient rocks are found in just once country. Today, we'll learn about ancient connections between Brazil and Africa, how Pangaea split apart, and how most iron mines got their start.

Miniseries Episode 5:

Asia is the largest continent, and has a lot of ancient rocks to share with the world. Today, we learn how to map a hidden continent using magnets, how copper forms in undersea castles, and how the Himalayas were born.

Miniseries Episode 7:

The oldest rocks on Earth are hidden deep in the Canadian North, 4 billion years old. For our final stop of our tour, we sneak a peek at these and other rocks we'll meet soon in the main series, including reefs made from bacteria and mysterious stones hidden beneath Greenland's glaciers.

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.

What's the next step after the oldest rock on Earth?

Today, we'll move the story forward 200 million years and 1,000 miles.

The time: 3.8 billion years ago... or maybe much older (March 3 on the Earth Calendar).

The place: Nuvvuagittuq (noo-voo-ah-git-took), Quebec, Canada, in the lands of the Inuit.

In this episode, we'll learn how this seaside outcrop was found and the ongoing debate about its' exact age. Depending on who you talk to, these are either the second-oldest rocks on Earth, or almost as old as the Earth itself.

Where does humanity get most of its' iron, and what do these rocks tell us about the ancient Earth?

Today, we'll learn about banded iron formations, the backbone of the modern steel industry an important stop in the search for early life and oxygen, and a rock that is impossible to make today. It's rare to find a rock as important to both economics and research. Along the way, we'll take a breath of fresh air, meet orange pond scum in a forest stream, and find a dagger carved from a meteorite.

Extra Credit: Find as many steel objects as possible around you, or search for bog iron in a local swamp.

What is the oldest major slice of rock, one that's relatively well-preserved, one that's fueled a half-century of research?

The episode's name kinda gives it away, but stay tuned as we meet the last location of Season 2: a series of rocks near Greenland's capital. Along the way, we'll meet the different groups of people who have settled on this remote island, and a geologist from the other side of the world. I'll also take a brief detour into why I unfortunately can't talk about every single ancient rock out there.

Extra Credit: Find a choir to sing in, or play some ping-pong.