A big week in space and year at Saturn this week on planetary radio. Hi everyone, welcome to Public Radio's travel show that takes you to the final frontier.

I'm Matt Kaplan.

Coming up a first anniversary review of Frontier. I'm Matt Kaplan.

Coming up a first anniversary review of Cassini at Saturn from one of our favorite people,

Linda Spilker, the Deputy Project Scientist for the Mission.

What a year it has been. Toward the end of our conversation,

you'll hear Linda talk about the just announced news of relatively warm water

and a possible nitrogen atmosphere at the south pole of Enceladus, one of the ring planets

icy moons.

Speaking of news, how does this grab you?

My very educated mother just served us nine pickles 2003 UB-313.

It's going to have to do until there's a catchier name for what may be our solar system's

tenth planet or 9th or 11th.

Astronomers really have to get together on this planet definition thing.

Anyway, a team headed by past planetary radio guest Michael Brown says 2003

UB 313 is bigger than Pluto and for the moment anyway much much farther away.

You can read about it and Enceladus at planetary.org.

The other big story is Discovery.

As we finished this week's show, NASA was about to announce whether astronauts would take a walk in space to make their first actual repair of a shuttle.

The Return to Flight mission has been extended by at least a day, partly so that Discovery's crew can transfer more supplies to the

International Space Station, which may not see another shuttle for quite a while.

Emily is up next with the tail of the biggest rock around so long as you're not

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