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Astronomy Cast Episode 220 from Monday, February 14, 2011. Mass Extinction Events.

Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know.

My name is Fraser Cain, I'm the publisher of University Day, and with me is Dr. Pamela Gaye, a professor at Southern Illinois University, Everestville.

And Pamela, how are you doing?

I'm doing well. How are you doing, Fraser?

I'm doing really well. Let's roll.

I have to be Valentine's Day.

For those of you confused, we're already confused. For those of you confused by the laughter week week.

We're recording this about six weeks late, so we're recording this in order.

We backdate things so that in the future, the weeks that we release four and the weeks that we release zero even out to one week.

This is going to be one of those four in a week, so lucky you.

All right.

So the earth seems like a safe place most of the time.

We have evidence of terrible catastrophes in the ancient past, times when almost all life on earth was wiped out in a geologic instant.

What could have caused so much devastation and will something like this happen again?

So there's a few of those like these names, right?

There's these various extinction events and they all many of them have names.

Katie extinction is the Katie extinction.

Yeah, yeah, the Permian extinction, the late Devonian.

The late Devonian.

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