This is CBS, I on the World. I'm John Batchel. Hotel Mars, episode N. I welcome my colleague and

co-host and co-pilot David Livingston of the Space Show, Dr. Space himself. And we're very

pleased to welcome the author, Robin George Andrews. His new book in stores now, published by

Norton in the U.S. and in the United Kingdom. How to Kill an Asteroid, the Real Science of

Planetary Defense. Though it reads like a romance, it is in fact a nonfiction book, and it describes

the conditions right now how we got here and where

we're going when it comes to planetary defense. Importantly, Robin makes the key point that we've found

the planet killers, mostly. There's always the odd comment that comes hurtling in from outside,

but in any event, the planet killer idea is off the table for now.

City killer, however, is to be emphasized.

Robin, congratulations and a very good evening to you.

What is the city killer and what is it going to look like when it comes? It's been here before. It'll come back. What are we

watching for? Good evening to you. Good and good morning. After evening to you. It's, yeah, so a city

killer is an interesting term because it's quite a dramatic sounding thing that isn't like

dreamt up by the media or anything. Like a city

killer kind of does exactly what it says. It's an asteroid that is around 140 meters or 460

feet across. And if it hit the city, even if it didn't actually hit the ground, it would explode in the

air and it would carve a heart out of the city. You know,

the impact zone for Mars around would be fluid for a second, which isn't great. And the blast wave

would seriously injure or kill people for tens of miles around. So it does exactly what the

name suggests. And I think contrary to what a lot of people think about when they think of asteroids,

it's quite small for space.

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