Ray Bradbury is back on Planetary Radio.

Hi, everyone. I'm Matt Kaplan.

We welcome you back to another installment of our show presented, as always, by the Planetary Society.

Special greetings go out to all of our new listeners at WMUH in Allentown, Pennsylvania.

We hope you'll join us each week on this continuing mission of exploration.

You're in good company.

Planetary Radio has attracted a family of regulars all over the world. By the way, you can find every past program at planetary.org

slash radio. That's planetary.org slash radio, part of the Planetary Society's comprehensive website. We'll tell you how to send us your

comments and questions at the end of today's show. And you've picked a good week to get acquainted.

We'll hear from beloved author, playwright, poet, and eternal optimist Ray Bradbury in just a

couple of minutes. Bruce Betts will be here toward the end of our half hour with What's Up?

His regular helping of universal truths, madness, and space trivia contests.

Yes, we give away a planetary radio t-shirt every week, but you have to work for it.

Let's get started as we usually do with a visit from the Planetary Society's

Emily Loctawala. Here's part one of her regular feature, Q&A. She's got rocks in her head, Martian

rocks. I'll be right back with Ray Bradbury at Uri's Night.

Hi, I'm Emily Lockdawala with questions and answers.

A listener asked, news reports about meteorites from Mars claimed to show that Mars had a warmer,

wetter environment in the past, or even that it had life.

But how do scientists know that the meteorites came from Mars?

Chemical analysis of meteorites found on Earth can reveal their Martian origin.

We have direct observations of the chemical composition of the Martian atmosphere from the Viking landers.

...