“Our solar system is a part of milky way”… Have you ever heard someone saying this? And then have you wondered what Milky Way is? Solar system is of-course, the group of Sun and all the other nine planets. Milky Way is a galaxy. Hmmm again confused? What is a galaxy?
You might think that all the stars in the universe are just randomly scattered. Nah! Instead they are nicely grouped together. Galaxy is a group of many million stars, some gases and space dust. Now you know that, there is an invisible force (also called pull) that attracts any two objects found in the Universe. All the stars in the galaxy are held together by each other’s pull to form a large group.
Galaxies are so big that we cannot measure it in kilometers or miles. So we use another measurement called a light year. Now what is a light year? We must leave it for now, and explain it to you another time!
Galaxies also come in many shapes and sizes. Our Milky Way is a spiral galaxy. Elliptical (egg shape) is another common shape for a galaxy like M87. Like how stars are collected together into galaxies, galaxies are collected together into clusters. The largest structures in the Universe are galaxy super clusters, which contain millions of galaxies and therefore trillion of stars. Some scientists say that there are more stars in the universe than there are grains of sand on every beach in the world. Whoa!
Did you know?
The word galaxy comes from the Greek word “galaxias” meaning “milky one” which they gave to our own galaxy for its appearance in the sky.