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Narrator: What happens if you have something like this, and you want to find out if something

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like this is inside? Obviously, you can

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but if you separate things out, the answer becomes

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clear. Scientists have the same problem. How do you know if there was

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once water on Mars...or, for that matter, life? Obviously

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you can't tell just by looking at pictures of Mars, but scientists think the answer may lie hidden in

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tiny molecules in Martian soil. So, how do you take apart

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a molecule to see what's inside? Luckily, scientists have a tool to do just

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that. It's called a mass spectrometer, and it lets us take an extremely close look

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at whatever we're studying. And even though Mars immediately comes to mind, mass

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spectrometers are used in multiple NASA missions. They're also used in labs for hundreds

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of scientific purposes. But the important question is: How does it work?

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Today, we'll be looking at a special kind of spectrometer called the quadrupole mass

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spectrometer. It's called this because of the four long poles that make up the center

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of the instrument. So say you have a sample that's been turned into a gas, and you want to

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find out if it contains certain things. The gas is sent into the mass spectrometer

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first hitting a piece called the ion source. Here, a stream of electrons

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hits the molecule, breaking it into fragments and giving each fragment a charge.

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Next, the fragments enter what's called the analyzer. Here,

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they're separated based on their mass, and the analyzer is tuned so that only

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the fragments we want to see make it through. Everything else flies off in a different

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direction. After this, the fragments hit what's called the detector,

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and scientists record the data. If you're looking for more than one kind, the analyzer

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can scan across a range of fragments, building up a record of not only what kind,

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but how many. Once you have these results, called a mass spectrum,

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you can verify that your sample in fact contains what you're looking for. And here,

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the real work begins. The mass spectrometer is a powerful tool, and

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by taking many samples, looking at the results, and studying what we find,

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scientists can work to discover not only the secrets of water and life on Mars, but

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also answers to bigger questions about the universe. And all by studying something

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as tiny as a molecule.

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