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\h        The Chandra X-ray Observatory orbits high above the Earth, peering into the blackest reaches of space.

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\h        Exploring the most menacing and magnificent features of the cosmos, this remarkable telescope is revealing what

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\h        our eyes can't, taking us beyond visible light.

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\h        The bad boys of astronomy, black holes inspire well-deserved wariness and strange fascination.

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\h        But what exactly are they?

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\h        Scientists harnessing the incredible power of Chandra have discovered that black holes     
    play a

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\h        critical role in both the development and demise of stars and galaxies.

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\h        While astronomers have long known that     
    black holes existed, it wasn't until Chandra     
    was launched in

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\h        1999 that some of their elusive secrets were revealed.

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\h        With its insightful perspective, Chandra has shed a revealing light on the dark mysteries of black holes.

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\h        Focusing on the deepest depths of space, Chandra has witnessed the gluttonous eating habits of some black holes.

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\h        HARVEY TANANBAUM: And in those     
    regions where the X-rays are deficient,

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\h        where the gas voids exist, is the same regions where you see the radio lobes,

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\h        these jets and lobes that are formed from the radios.

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\h        So you know that energetic particles are being shot away from the black hole by some kind of mysterious process,

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\h        and they're clearing the gas away.

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\h        They're pushing the gas aside.

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\h        Because the gas has a density and a temperature, properties that we measure in the X-rays,

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\h        it's very easy to calculate the amount of work that's needed to clear these voids.

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\h        So you can actually measure the energy that's carried out by these jets of particles.

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\h        However, not all black holes mean certain doom for their neighbors.

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\h        Consider for example, one known as Sagittarius A Star, a black hole churning at the center of our own Milky Way galaxy.

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\h        Unlike its more malicious siblings, this black hole appears to be protecting a flock of young stars instead of eating them.

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\h        TANANBAUM: With Chandra, we're able to     
    measure the density and temperature of the     
    gas just outside

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\h        the black hole at the center of the Milky Way galaxy,

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\h        and there's plenty of gas there and it's hot!

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\h        And we should see, even with conservative theories, instead of 100 billion times the amount of radiation that we see,

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\h        we should see a billion times or some 100 million times; it doesn't matter, it's a large factor greater than what we see.

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\h        Equal parts stellar destroyers and cosmic creators, Chandra's black holes exhibit dual nature.