Starts With A Bang podcast

Starts With A Bang #118 - Snowball Earth


Listen Later

When we search for life in the Universe, it makes sense to look for planets that are similar to Earth. To most of us, those signatures would look the same as the ones we'd see if we viewed our planet today: blue oceans, green-and-brown continents, polar icecaps, wispy white clouds, an atmosphere dominated by nitrogen and oxygen, and even the modern signs of human activity, such as increasing greenhouse gas emissions, planet modification, and electromagnetic signatures that belie our presence.

But for most of our planet's history, Earth was just as "inhabited" as it is today, even though it looked very different. One fascinating period in Earth's history that lasted approximately 300 million years resulted in a planet that looked extremely different from modern Earth: a Snowball Earth period, where the entire surface, from the poles to the equator, was completely covered in snow and ice. This isn't just speculation, but is backed up by a remarkable, large suite of observational and geological evidence.

So what was Earth like during this period? How did it fall into this phase, how did it remain trapped in that state for so long, and how did it finally thaw again? To help explore this topic, I'm so pleased to welcome PhD candidate Alia Wofford to the program, who conducts intricate climate models of early Earth to try to reproduce those early conditions. From that work, we're learning about what we should be looking for when it comes to potentially inhabited exoplanets, because Earth has been inhabited for around 4 billion years, and wow, has its appearance changed over all that time. Have a listen and see for yourself!

(This illustration shows a frozen-over planet, but one that still possesses a significant liquid ocean beneath the surface ice. Many worlds in our Solar System may be described by this scenario at various points in cosmic history, including even planet Earth more than two billion years ago. Credit: Pablo Carlos Budassi/Wikimedia Commons)

...more
View all episodesView all episodes
Download on the App Store

Starts With A Bang podcastBy Ethan Siegel

  • 4.7
  • 4.7
  • 4.7
  • 4.7
  • 4.7

4.7

65 ratings


More shows like Starts With A Bang podcast

View all
Big Picture Science by Big Picture Science

Big Picture Science

933 Listeners

Planetary Radio: Space Exploration, Astronomy and Science by The Planetary Society

Planetary Radio: Space Exploration, Astronomy and Science

1,335 Listeners

StarTalk Radio by Neil deGrasse Tyson

StarTalk Radio

14,202 Listeners

Universe Today Podcast by Fraser Cain

Universe Today Podcast

549 Listeners

Ask a Spaceman! by Paul M. Sutter

Ask a Spaceman!

826 Listeners

The Quanta Podcast by Quanta Magazine

The Quanta Podcast

509 Listeners

Space Nuts: Astronomy Insights & Cosmic Discoveries by Professor Fred Watson and Andrew Dunkley

Space Nuts: Astronomy Insights & Cosmic Discoveries

229 Listeners

SpaceTime: Your Guide to Space & Astronomy by Stuart Gary

SpaceTime: Your Guide to Space & Astronomy

301 Listeners

Into the Impossible With Brian Keating by Big Bang Productions Inc.

Into the Impossible With Brian Keating

1,050 Listeners

Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas by Sean Carroll | Wondery

Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas

4,121 Listeners

Daniel and Kelly’s Extraordinary Universe by iHeartPodcasts

Daniel and Kelly’s Extraordinary Universe

2,318 Listeners

The Origins Podcast with Lawrence Krauss by Lawrence M. Krauss

The Origins Podcast with Lawrence Krauss

509 Listeners

The Supermassive Podcast by The Royal Astronomical Society

The Supermassive Podcast

281 Listeners

Why This Universe? by Dan Hooper, Shalma Wegsman

Why This Universe?

361 Listeners

The Joy of Why by Steven Strogatz, Janna Levin and Quanta Magazine

The Joy of Why

507 Listeners