This is planetary radio. Hi everyone I'm Matt Kaplan.

Mars looms large on this week's planetary radio just as it is growing in the sky.

Join us for a special talk by Dr. James Bell of Cornell University as he examines the recent

robotic exploration of Mars and the most ambitious mission ever beginning next month.

We'll have that right after Emily tells us about the search for life near Earth, but not on Mars.

Hi, I'm Emily Loch Duwala with questions and answers.

A listener asked, I've been following the debate on whether that Mars meteorite contains evidence

of early life on Mars.

I wondered if anyone investigated the Apollo moon rocks with the same zeal.

As a matter of fact, a lot of work went into searching the lunar samples for organic materials.

Organic chemicals contain carbon and oxygen and are considered along with water to be the building blocks of life.

Scientists did find reduced carbon in the lunar surface layer,

most of which arrived there from asteroids in the solar wind.

At one time, papers reported the presence of small quantities of complex organic compounds,

like amino acids, the building blocks of proteins in the lunar samples.

Sadly, these compounds proved to be artifacts of the researcher's analytical techniques

and had not come from the moon at all, so there is no evidence for complex organic materials on the moon.

But as they say, absence of evidence is not evidence of absence.

Could there have been life on the moon?

Stay tuned to planetary radio to find out. Jim Bell is a professor of astronomy at Cornell, where Carl Sagan once taught, and like

Sagan, Dr. Bell is intimately involved with planetary exploration, with a special focus on Mars.

Seven years of Jim's hard work are about to climax in the launches of the twin Mars Exploration

...