One of my favorite parts of observing the night sky, of going sky watching, is the depth,

that you're not just looking at things in our own atmosphere or even our own solar system.

These objects there sending their light to you are thousands,

tens of thousands of light years away. These incredibly, almost impossibly distant objects. And you

get to see them. So there's this incredible richness and depth to the night sky. This almost

overpowering, to me at least,

sense of depth.

And the things you look at, if you look in any one particular direction in the night sky,

you are looking at something incredible.

For example, if you look in the direction of the constellation Sagittarius, you're looking in the direction

of the center of our own Milky Way galaxy.

In the center of the Milky Way is a dense cluster, a bulge of stars, of nebula, of gas.

It's the bustling downtown as viewed from way out here where our solar system is

out here in the suburbs. And it's a beautiful, if you get a chance to see the center of the

Milky Way galaxy through binoculars or a telescope, it's just flooded with stars. But deep in the

center of the Milky Way galaxy, there is a black heart, a black hole, four million

times more massive than the sun. The closest example that we have of a class of giant black holes

called supermassive, appropriately named supermassive black holes.

This one particular black hole has a name, Sagittarius A. Star.

This object, like I said, four million times more massive than the sun, is a monster.

It's a beast, but it's well hidden. It's obscured by the countless stars surrounding it and the

clouds of gas and dust enveloping it. And right now, it's slumbering. It's sleeping. It's not

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