The facts of the Universe always leave me spinning. With the naked eye, I can see a couple of thousand stars strung across a night sky that seems to have no end. Above me is the Milky Way, a disc-shaped island in space which is our home and which, therefore, we see from the inside. It is a sweeping band of light, turning in space like a giant wheel, composed of 300,000 million stars. Each one shines because it is a furnace of raging gas held together by the force of gravity, and each shine as brightly as our sun, itself one of those millions upon millions of stars, but located much closer to the edge.
Until recently, scientists thought that this was the extent of the Universe. That was mind-boggling enough. But more powerful telescopes, together with research on the analysis of light from those fuzzy patches of brightness called the nebulae, revealed something strange: a subtle shift in the colors of the spectrum from the blue end to the red end. This so-called red shift indicated that the distance between them and us was growing greater, rather like the siren of a police car or ambulance has a lower pitch the further it gets from us.
In 1990 the Hubble space telescope was finally ready to transmit images back to earth. It was named after Edwin Hubble, who in 1929 had proved that the Universe is expanding, and fast. In the time it takes you to read this post, it will have expanded about a quarter of a million miles in all directions.
The Hubble telescope was pointed at areas of sky which to a small telescope looked blank. What the resulting photographs revealed was that what had previously been seen as blurry blobs of light were in fact galaxies like ours, islands in space of which there are now thought to be at least 10,000 million, each home to some 100,000 million stars. That would be roughly 1,600 galaxies for every person on earth. Clusters contain two or three galaxies; superclusters contain thousands of them. Imagine looking back from somewhere out there among the myriad galaxies, seeing one teeny dancing snowflake suspended in midair. That is our Milky way. Huge, but no longer the center of the Universe. It’s facts like these that leave me spinning. And humbled.
WATCH
Watch the following clip for a perspective of where the Earth and our Sun stands in relation to other stars in the vast Milky Way and beyond. Near the end of the video, you will see the Andromeda Galaxy, the nearest galaxy to our own. It is 2.5 million light years away from the Earth, roughly similar to the width of the Milky Way (note: one light year equals 9.46 trillion miles). Video credits: Pablo Carlos Budassi.