A astronomy cast, episode 609, the benefits of volcanoes.

Welcome to Astronomy Cast, a weekly facts-based journey through the cosmos where we help you

understand not only what we know, but how we know what we know.

I'm Frieza Kane, publisher of Universe Today, with me as always as Dr. Pamela Gay, a senior

scientist for the Planetary Science Institute and the Director of CosmoQuest.

Hey Pamela, how are you doing?

I am doing well.

It is glorious summer weather here, which means it isn't good for observing because you

will be carried away by the mosquitoes before you get good data.

But it also means we have four episodes before summer hiatus this year.

That's true.

Two things that I think are really important right now, that people should be aware of.

One, Juno sent back new pictures of Ganymede and they are stunning.

The first time we've seen close-up pictures of Ganymede since Galileo, they're amazing.

Actually, I found out from one of the team scientists that Galileo's data wasn't as good

as Voyagers.

So this is the first time we've gotten data this good since Voyager.

Oh wow.

Yeah.

So it's amazing.

And I learned something new looking at those images and then talking with Candace Hansen.

Did you notice how the craters have divots in the center?

...