MEMBER REVIEWS: 1) This is a Nova program about how rocks and life co-evolved. Rather than dividing Earth history into the usual eras and epochs, they use chemical markers and colors. Black earth – roughly the Hadean. Grey Earth when things cooled a bit, and then blue Earth when water flooded the surface. They go into the chemical precursors of life, and how it may have evolved. Then they talk about life changing the chemistry with all that oxygen. (Why is there air? Stromatolites.) This created red Earth. Then comes white Earth – snowball Earth. And finally, green Earth with the Cambrian explosion. This is a new way to look at how the Earth and life co-evolved, and it makes you think differently about a few things. It is well worth watching more than once.

2) This is a Nova program and absolutely fascinating. The premise is that without clays and other minerals, life would never have happened. Not so much the actual mineralogy, but the structural forms of clays and other rocky stuff allowed the chemical precursors of life hiding places where they could consolidate and rearrange themselves to create actual life. I give this one an unconditional thumbs up.

Description: Four and a half billion years ago, the young Earth was a hellish place–a seething chaos of meteorite impacts, volcanoes belching noxious gases, and lightning flashing through a thin, torrid atmosphere. Then, in a process that has puzzled scientists for decades, life emerged. How did it happen? NOVA joins mineralogist Robert Hazen on the rocky trail to resolve this enduring mystery. As Hazen journeys around the globe–from an ancient Moroccan market to the Australian Outback–he advances a startling and counterintuitive idea–that the rocks beneath our feet were not only essential to jump-starting life, but then, as microbes flourished and took over the biosphere, life helped give birth to hundreds of minerals we know and depend on today. This intriguing perspective of the co-evolution of Earth and life is reshaping the grand-narrative of the story of our planet. In this stunning adventure through billions of years of history, the story of life on Earth is revealed as fundamentally interwoven with the epic, unfolding story of Earth itself.