One year to go at Saturn, this week on planetary radio.

Welcome, I'm A Kaplan, of the Planetary Society with more of the Human Adventure

across our solar system and beyond.

Our most frequent guest, Linda Spilker, of the Cassini Mission, returns with more news from the

Queen of planets, its rings and moons.

Bill Nye is away this week, but we'll hear from senior editor Emily Lockwale in a moment, and Bruce Betts will drop

by in virtual fashion with night sky and other goodies, including a new space trivia contest.

Emily Good is always to talk to you this time about a mission that I think a lot of people

or at least a lot of Americans are not as aware of as they probably should be.

Yeah this is a European Space Agency mission called Gaya, and Gaya is not a planetary mission.

It's a mission that's simply designed to survey the positions of stars in our galaxy.

It is returning some truly stunning results, just the numbers alone tell the story.

Yes, we're talking about literally billions of stars in our galaxy.

And what it's doing is it's mapping the density,

the position, and eventually the motions of all of those stars

so that we'll be able to intimately understand

how our galaxy evolves with time as the stars move through

their own individual orbits around the galaxy center. Now this is all well and good

but it has a surprising amount of significance for people who maybe don't care about other stars but do care a lot about

planetary science.

I think that most of us do care about stars even if we only care about planets most of the time.

But yeah, so planets are by definition

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