Bedrock: Earth's Earliest History

Why are some ancient rocks well-preserved, while others are extremely messed up?

Today, we'll take a side quest from our Greenland arc to learn more about metamorphosis, which changes rocks beneath our feet. On the way, we'll transform toast into cookies, take an elevator ride deep into the crust, and meet an ancient rock with a babyface.

Extra credit: make some toast, or go looking for butterflies.

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.

How did the Man in the Moon form? What does the Moon's Far Side look like?

Today, we'll learn about the most visible remnant of the ancient world- the pattern of dark lunar rocks that stares down on us each night. On the way, we'll hitch a ride with a flying fax machine, play a game with crystals in magma, and learn why bananas are slightly radioactive (and why that doesn't really matter).

Extra Credit: Try to send me a fax, or just eat a banana.

When did the Moon's craters form? Can they tell us any stories about the ancient Solar System?

Today, we'll learn some early explanations for lunar features, meet a "lunatic asylum" of planetary geologists, and learn how the larger planets might have bullied their smaller neighbors.

Extra Credit: Watch Apollo 13, or The Right Stuff.

What are the oldest disputed fossils on Earth? Why are they disputed?

Today, we wrap up our tour of Nuvvuagittuq in northern Quebec, 3.8 billion years ago, March 3rd on the Earth Calendar. In 2017, microscopic rusty threads were discovered inside these rocks, thinner than a human hair. Were they bacteria, or something else entirely? Stay tuned to find out!

Extra Credit: Learn how to make a chemical garden, or find a piece of chert, flint, jasper, agate, or onyx.

Common Descent Interview: https://youtu.be/amQ9rntfKV0?feature=shared

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 are Earth's oldest volcanic rocks, and how did they form?

Today, we'll explore the seafloor 3.8 billion years ago through dark basalt rocks in Nuvvuagittuq, northern Quebec. Along the way, we'll earn a green belt in geology, rest our heads on volcanic pillows and journey to the deepest spot in the modern ocean.

Extra Credit: Try to find dark black basalt in a building or countertop near you.

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.

If the sun was dimmer 4 billion years ago, how did the Earth stay warm?

Today, we learn how just a small percent of Earth's atmosphere goes a long way in controlling global climate, both today and in the ancient past. Along the way, we'll visit an imaginary frozen Earth without any sun, a hazy giant moon of Saturn, and learn exactly what the greenhouse effect is.

Extra credit: Visit a greenhouse, or find a cleaning product with ammonia.

How has the Sun changed over the past 4 billion years?

While the Sun may seem unalterable, it has brightened dramatically over Earth's history, with major implications for our world. Today, we'll meet a team of women who catalogued thousands of stars in the 1800s, play in a galactic ball pit, and puzzle over a cosmic paradox alongside Carl Sagan.

Extra Credit: Watch Cosmos (1980)