Understand that the Sun is one of hundreds of billions of stars in the galaxy, and that there are countless galaxies in the universe.
Where we really live
Our address in the universe
All the stars you can see at night with the naked eye belong to one galaxy — the Milky Way. A galaxy is a gigantic collection of stars, gas, and dust held together by their shared gravity.
The Milky Way is a spiral galaxy: picture a flat disk with curving arms, like a pinwheel. It holds about 200–400 billion stars. Our Sun is just one of them, and it lies not at the center but closer to the edge, in one of the spiral arms.
That pale band stretching across the whole sky on a dark night is our Milky Way. We see the disk of our galaxy from inside, edge-on, so it looks like a hazy path of countless distant stars.
And that's only the beginning of the scale: there are hundreds of billions of such galaxies in the universe. The Milky Way, by the way, is slowly approaching the neighboring Andromeda Galaxy; in about 4 billion years they will merge into one.
Lesson notes
Our address in the universe
All the stars you can see at night with the naked eye belong to one galaxy — the Milky Way. A galaxy is a gigantic collection of stars, gas, and dust held together by their shared gravity.
The Milky Way is a spiral galaxy: picture a flat disk with curving arms, like a pinwheel. It holds about 200–400 billion stars. Our Sun is just one of them, and it lies not at the center but closer to the edge, in one of the spiral arms.
That pale band stretching across the whole sky on a dark night is our Milky Way. We see the disk of our galaxy from inside, edge-on, so it looks like a hazy path of countless distant stars.
And that's only the beginning of the scale: there are hundreds of billions of such galaxies in the universe. The Milky Way, by the way, is slowly approaching the neighboring Andromeda Galaxy; in about 4 billion years they will merge into one.