BY DAVID ABBOU
IT IS our island in the sea of space, but we cannot leave it. Our Milky Way galaxy we live in can be seen under dark skies as a ghostly band of light stretching from horizon to horizon, especially in late summer and early fall. when we look towards its luminous center. Every star we see in the sky belongs to it, including our own sun.
The Milky Way is a huge galaxy spanning 100,000 light years. Our solar system resides in its outer suburbs about 26,000 light years, or 153 quadrillion miles, from its center. It’s too far for the human brain to understand, but it’s also far enough to be a safe distance from the monstrous black hole residing in the center of the galaxy.
Since we live inside the Milky Way, we cannot see or photograph it from the outside, so we can only see it from our internal perspective to determine its structure. It turns out that the Milky Way is a type of galaxy known as a barred spiral containing around 200 billion stars, many of which look like the sun. Most of these stars are surrounded by planets, a recent and important discovery in science and astronomy that increases the chances of finding extraterrestrial life in the future.
Just over 100 years ago, astronomer Edwin Hubble (hence the name of the Hubble Space Telescope) first discovered that other galaxies existed outside of our own. Before that, astronomers had no idea of the existence of other galaxies. Today, more than 2,000 billion galaxies are estimated to reside in the observable universe, a number that is sure to increase as telescope technology advances, but the most important will always be our own Milky Way.