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Distance

Let’s start off by talking about our little piece of the universe. To truly understand it, one must have a simple (not the best term but please bear with me) understanding of distances. We all pretty much know that Earth is the third planet in our Solar System and is 93 million miles from the sun. Even that is not easily grasped.

NASA launched Voyager 1 in 1977 and it has been traveling at a speed close to 40,000 miles an hour since its launch. (It could orbit the Earth almost twice in one hour.) It has been traveling at that speed for a little more than 38 years and, just recently, passed the outer edge of the Solar System and entered intergalactic space. Think about that! Thirty eight years to leave the Solar System. Traveling at its current speed, it will take Voyager 1,634 more years to travel one light year. The closest star to us (other than our sun) is a little further than three light years. Have I lost you yet?

The point I’m trying to make here is that even traveling at 40,000 miles an hour, the closest star (Proxima Centaura) will take longer than a human life span to reach. Much longer! About five thousand years will get you there at the speeds we’re currently launching rockets from Earth. Now, if the ship we launch is capable of continuing to accelerate to much higher speeds, then the time could be shortened. That would require some means of propulsion that we currently don’t have. Think about how large the ship would have to be to carry enough fuel.

However, the topic today is distance, not how to travel quickly. This next part of the discussion is going to get, as my good friend Roy would say, HEAVY. We’re going to use a light year to measure things and just remember that it takes sixteen hundred years to travel one light year at 40,000 miles an hour.
The sun is one star in the galaxy our Solar System is in. There are more than three billion stars in the Milky Way and our galaxy is approximately 120,000 light years across. Let’s pause a moment. Using our measures, it would take Voyager one hundred and ninety two million years to fly the width of the Milky Way. On Earth, 192 million years ago, T-Rexes were the boss hogs. (They would meet their undoing 27 million years later when the giant asteroid slammed into Earth causing a massive extinction. But that’s another story. Check out the series Trapped in Time which deals with that time in history.)

At this point, I hope you have an idea of the sheer size of the galaxy we inhabit. The Milky Way is a beautiful spiral galaxy with two (some scientists are now claiming three) arms that spin around the central black hole, whose gravity keeps everything in its place. Everything in the Milky Way spins around that black hole. It takes the Milky Way 220 million years to complete one rotation around the central black hole.

Alright, enough of the small stuff. Are you ready to really expand your mind? Our galaxy is part of a cluster of galaxies called the Local Group. There are 54 galaxies that appear to revolve around a point located between the Milky Way and the Andromeda Galaxy. Most of the galaxies that comprise this cluster are dwarf galaxies that are much smaller than the two largest galaxies (Milky Way and Andromeda). Andromeda is 2.5 million light years from the Milky Way and is currently headed directly toward us. In four billion years, the two will collide and merge into a super galaxy. (Keep your eyes out for that one.) The space these fifty four galaxies are located in is 10 million light years across. (If you google The Local Group, you’ll find a list of the 54 galaxies and where they’re located.)

So now you’re getting an idea of our little nook in the universe. However, there’s one more thing and I’ll end this long diatribe. Most of my stories are written with the various galaxies in our cluster in them. However, the galaxy I use most often is M-87. Ohhh, what a monster it is! You see, the Local Group is part of a much larger group of Galaxies named the Virgo Supercluster.

The Local Group is part of this giant gathering of galaxies which number between thirteen hundred and two thousand galaxies. They are bound to each other through gravity and are all revolving around a center located about 54 million light years away. M-87 is the largest galaxy in the cluster and is estimated to be more than six to eight times larger than the Milky Way. However, it is a ball shaped galaxy and it is estimated to contain 2 trillion stars compared to the Milky Way’s three billion. (That’s more than six hundred times more stars.) I use it in many of my stories because there’s six hundred times more stars where intelligent life could exist. 

Understanding just the area our galaxy exists in is not easy but it’s a start at getting a feel for just how large the universe truly is. This is something that must be digested in small bites and makes appreciating the larger picture a bit easier. I hope you find this information interesting and helpful.  
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