The night time stars are like raindrops on a window we look through to see what lies beyond . All the individual stars we see with our unaided eye are within a small section of our own galaxy, the Milky Way. The rest of the universe lies beyond.The Milky Way Galaxy is a group of several hundred billion stars, in the shape of a disk with spiraling arms. It is 100,000 light years wide and 10,000 light years thick (a light year is the distance light travels in one year). Our own star, the sun, is about 8 light minutes away from Earth. The closest neighbor star is about 4 light years away. The furthest star we can see with the naked eye is a blue supergiant about 1,800 light years away.
Beyond the Milky Way are unknown numbers of other galaxies in all directions, each with vast numbers of stars. About 22 of these are relatively "close" to our galaxy. Scientists have named this group of galaxies, that we are part of, The Local Group. There are two dominant, giant galaxies in The Local Group. One is our own, the Milky Way. The other is the Andromeda Galaxy.
The Andromeda Galaxy is about 2 million light years away from the Milky Way, about 20 times as far as the width of the Milky Way itself. Each of these two giant spiral galaxies appears to have several smaller "satellite" galaxies clustered around it. Two satelite galaxies of the Milky Way, named the Large Magellanic Cloud and the Small Magellanic Cloud, are visible with the naked eye from the southern half of the Earth. The Andromeda Galaxy is visible with the naked eye from the northern half of the Earth. In fact, it is the one and only object we can see with just our eyes that is not within the Milky Way Galaxy.
Our Local Group of galaxies is part of a still larger cluster of galaxies called the Local Supercluster. It is estimated to be about 300 million light years across. It is one of many, many other superclusters, that astronomers are just beginning to identify.
The stars are the raindrops on the galactic window through which we see the universe beyond.
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