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This is Stephanie Desmond. Today I talk to Andy Rifkin, Johns Hopkins astronomer, who was involved in last year's NASA mission to change the orbit of an asteroid in space.

We talk about what it's like to move from setting stars in the sky to a project that really someday could save humanity in the event of a planetary emergency.

Let's listen.

Andy Rifkin, thanks so much for joining me.

Thanks for having me.

So you are a planetary astronomer who was involved in that really cool project last year,

I'm sure it's ongoing, where you moved the orbit of an asteroid.

Tell us more about that.

Yeah, absolutely. I'm the investigation lead for the double asteroid redirection test, or dart.

It's a test of a planetary defense technique called the kinetic impactor, which basically is you take your spacecraft,

you ram it into an asteroid you're worried about, and you change its orbit. In case of an actual emergency, you would change the orbit into an asteroid you're worried about and you change its orbit.

In case of an actual emergency, you would change the orbit that an asteroid had around the sun

so that the asteroid in the Earth don't get to be at the same place at the same time.

For DART, what we did was change the orbit of an asteroid that's orbiting another asteroid.

So it's a moon of an asteroid.

So we didn't change the path around the sun.

We just changed the path of the asteroid around its main body.

And this was a success.

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