The Milky Way Galaxy
....and other celestial bodies...
There is only one star in our solar system: the Sun. While there are billions of stars in our galaxy, the Milky Way, the Sun is the sole star that our planets, dwarf planets, moons, asteroids, and comets orbit.The Milky Way is our home galaxy, a vast collection of hundreds of billions of stars, along with gas, dust, and dark matter, all held together by gravity. Our Sun is just one average star among this immense number, located in one of the galaxy's spiral arms.
Facts about our galaxy:
- The Milky Way is ancient. Scientists estimate that the Milky Way is about 13.6 billion years old, which is nearly as old as the universe itself, which is estimated to be about 13.8 billion years old.
- We can't take a picture of it from the outside. Because we're inside the Milky Way, we don't have a vantage point to take a full picture of it. Any image you see of our galaxy is either a picture of another spiral galaxy or an artist's rendition.
- It's estimated that the Milky Way contains between 100 and 400 billion stars. This is not a precise number because it's impossible to count every single star, especially since we're located within the galaxy itself.
- Our solar system is on the move. The Sun and our entire solar system are orbiting the center of the Milky Way at an incredible speed of about 515,000 mph (829,000 kph). Even at this speed, it takes our solar system roughly 230 million years to complete one orbit around the galactic center. This time period is known as a galactic year.
Learn more about the Milky Way Galaxy here.