Winget Messenger is off to Mercury on planetary radio. Radio.

I'm at Kaplan. Sean Solomon is principal investigator for the messenger mission headed this week to Hot Little Mercury. He's our guest on today's show.

Bruce Bats brings news of What's Up, including a meteor shower and a new trivia contest.

We'll begin with Emily's explanation of both the Yellow Moon and the Blue Sky.

And you can't ask for much more than that.

Stay with us. Hi, I'm Emily Lockawala with questions and answers. A listener asked, why does the moon appear

gray in Apollo pictures when it appears yellow from Earth to the naked eye and through a telescope?

Asking why the moon looks yellow from the Earth is just another way of asking why the sky is blue.

If the Earth had no atmosphere, our sky would

look black even during the day and the sun would be astonishingly bright. But the nitrogen and

oxygen in our atmosphere scatters some incoming sunlight, which has the effect of dimming

the appearance of the sun and brightening the appearance of the sky.

Nitrogen and oxygen scatter short wavelength blue light much more than longer

wavelength red and yellow light which makes the sky appear blue. What does that have to do

with the moon's color? Stay tuned to planetary radio to find out. Mercury surface, space environment, geochemistry, and ranging.

With a little imagination, those seven words become messenger, an apropos name for a mission

to the innermost planet of our solar system.

Though it's not nearly as far from us as Jupiter or Saturn, we really know very little about Mercury.

Much of what we do know was discovered three decades ago by Mariner 10, the only other spacecraft

to visit the planet.

That ignorance will end when Messenger passes Mercury and later

goes into orbit above its crater-covered surface. Every mission presents unique challenges

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