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The Milky Way Galaxy

The Milky Way is the galaxy where our solar system is located. It is a huge collection of billions of stars, along with planets, gas, dust, and other space objects. On a clear, dark night, the Milky Way looks like a bright, milky band of light stretched across the sky, which is how it got its name.

Scientists believe the Milky Way is about 13.6 billion years old and contains somewhere between 100 and 400 billion stars. Our Sun is just one of them.

Our solar system sits inside one of the Milky Way's spiral arms, called the Orion Arm. This arm is located about 26,000 light-years away from the center of the galaxy, so we're actually out in one of the outer arms, not at the center.

Scientists also believe there is a supermassive black hole at the very center of our galaxy, called Sagittarius A*. It is one of the largest black holes known and it is about 4.3 million times heavier than the Sun. Black holes like this are usually described as having a few key parts: the event horizon (the point past which nothing can escape), the photon sphere, the accretion disk (a ring of swirling gas and dust), and the singularity at the center.

Our solar system doesn't just sit still. It orbits the center of the Milky Way at an incredible speed, around 514,000 mph. Even at that speed, it still takes about 250 million years to complete just one full orbit around the galaxy!

We don't feel this enormous speed for the same reason you don't feel the speed of a plane cruising smoothly through the air: everything around us ,the Earth, the Sun, and the rest of the solar system is moving together at the same steady speed, so there's nothing to feel relative to. It's only when speed suddenly changes, speeding up, slowing down, or turning ,that we actually feel motion.

The Milky Way is just one of an estimated two trillion galaxies in the universe, but for us, it's the one that matters most. Without it, our solar system, our Sun, and our Earth wouldn't exist at all.