France invested over a billion dollars to clean up the river sun before the Paris Summer Olympics and it's still polluted with well poop.

What we see is not necessarily a sign that the

infrastructure project are not working. They might be working and the river is

also polluted from upstream. It's Friday June 27th, or as we call it around here, it's Science Friday.

I'm Scifry producer Shishonabucks found.

With the Paris Games less than a month out,

will the send clear up in time for swimmers to take a dip for the first time and over a century?

We'll dive into the science of urban river pollution.

But first, here's guest host Anna Rothschild with some of the other top science

news of the week.

This week, China's Chang' uh-6 robot lander returned to Earth, bringing samples of rock and dust from the far

side of the moon. Here to tell us more and other stories from this week's news is

Rachel Feltman, host of the weirdest thing I learned this week,

and Scientific American Science Quickly Podcasts.

Welcome back, Rachel.

Thanks for having me.

So we talked about this moon mission when it was just about to land. What's it been up to since then?

So it has successfully landed back in Inner Mongolia and scientists are now going to be able to start studying the rocks that it

brought home from the far side of the moon which is super cool.

Yeah that's so exciting. So what could these samples tell us about the moon that we don't already know?

These will be our first samples from the far side of the moon.

China is the first space agency to successfully get landers over there at all. And the thing to keep in mind is that before the Apollo 11 mission brought back any moon rocks, we were totally wrong about how we thought the moon formed and we still don't have like the

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