Watch the Program Teachers

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Early Clues

This chapter:

• explains how astronomers study the galactic center.

• reports what one astronomer found when he studied the galactic center with an infrared detector.

running time 4:31

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Nature's Most Bizarre Creature

This chapter:

• states where the sun is located in the Milky Way galaxy.

• notes that astronomers believe a black hole exists at the galaxy's center.

• reviews Einstein's view of space, time, and gravity.

• explains the nature of a black hole and states that the laws of physics don't apply inside one.

running time 6:56

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Tracking the Monster

This chapter:

• states that a large black hole dominates the center of the Milky Way.

• indicates that the most powerful telescopes reveal only a blur because the motion of gases in Earth's atmosphere distort distant astronomical objects.

• explains how astronomers found a way to help eliminate the distortion and observe the center of the galaxy.

• explains how the pattern of stars in the galactic center revealed that they were circling a supermassive black hole.

running time 6:51

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Inside Black Holes

This chapter:

• explains how black holes form.

• notes that there are millions and millions of small black holes—about 10 miles in diameter—in our galaxy that cannot be seen.

• describes what happens when matter approaches a black hole.

• tells what would happen if a person were to enter a small black hole.

• simulates what the interior of a supermassive black hole would be like.

running time 6:24

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Actors on the Galactic Stage

This chapter:

• questions whether the supermassive black hole at the center of the Milky Way is unique.

• reports on the Sloan Digital Sky Survey that took a census of galaxies within a billion light years.

• shows how astronomers detect how gas swirls into a black hole.

• reveals that nearly every galaxy has a supermassive black hole at its center and explains how black holes arise at a galaxy's center.

running time 10:09

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Our Very Own Monster

This chapter:

• explains that a supermassive black hole can be quiet or active.

• notes that the black hole at the center of the Milky Way galaxy was quiet until 1999 when the Chandra X-ray Observatory detected an explosion near its event horizon.

• follows astrophysicists' five-night study of activity in the black hole at the center of the galaxy and describes what was learned each night.

running time 7:06

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Fate of the Milky Way

This chapter:

• speculates what it might take for the area around the black hole to be active again.

• explains that in time, galactic cannibalism will occur when the Andromeda galaxy is 2 million light years away and is charging toward our galaxy.

• displays a simulation of what might occur to the Andromeda and Milky Way galaxies.

• states that black holes actively shape the universe.

running time 6:20