They say that on a clear day you can see forever, but on a clear night you can see even farther. Do you want to try for the farthest object visible to the naked eye?
You will need a very clear, dark night with no moon getting in your way. Get out of town away from distracting lights, and do not forget a pair of binoculars if you have them.
Find the constellation Cassiopeia, the Queen, in the North. It looks like a W — which has two points, and so does Cassiopeia. One of them looks flattened like somebody sat on it. You do not want that one. The other one is nice and sharp. Use that one to point over about the width of the entire W.
This is where those binoculars will come in handy. See if you can find an oblong fuzzy spot. Once you locate it with binoculars, see if you can still find it without them. If you see it, congratulations! This is the biggest and the farthest away thing you have ever seen.
How far away is it? Those little photons hitting your eyeballs coming from that fuzz ball, have been traveling at the speed of light,186,282 miles per second, across an unimaginable vast void of space for a staggering two and a half million years. Wow!
What is it? Now you are looking beyond our own Milky Way galaxy to another galaxy entirely, the Andromeda galaxy. With a spiral shape like our own, it is often referred to as our sister galaxy, but she is our big sister with twice the number of stars as our own Milky Way.
The name Andromeda comes from the constellation of stars in which she is found. She was the beautiful daughter of Queen Cassiopeia and King Cepheus. There are some interesting mythological stories associated with these characters which I will tell you about sometime.
Looking up at Andromeda, try to let go of your perception of what is up and down and try to imagine that you are looking downhill in the biggest sense of the word. Andromeda has more stars than the Milky Way. More stars means more mass. More mass means more gravity. More gravity means we are falling into Andromeda. The Earth, our sun, every star in the sky, and yes, even you are falling at over a million miles an hour into Andromeda.
Collision course
There is good news and bad news about all of this. The bad news first. We are going to crash, and neither of our political parties have a plan to do something about this. The good news is that you do not have to rush out and buy collision insurance tomorrow. It will be a while before we get there, about 3.5 billion years.
So what will happen and what will it look like a few billion years from now. First of all our friendly sun will turn on us long before we get there, expanding into an angry red giant, frying us into a crispy critter and swallowing the remains whole in a gulp or two. We will have to move somewhere else, if we want to witness the collision.
The two galaxies approaching each other at an angle will fill up most of the sky. Dust and gas in both galaxies compressed by the titanic gravitational forces unleashed by the event will precipitate an unprecedented period of new star formation. Millions of hot blue-white stars will be scattered across the sky. You might think stars will be crashing into one another right and left, but astronomers predict few if any star collisions. The stars are simply too far apart.
A whole new galaxy will be created, quite different from either of its predecessors. Astronomers have gotten ahead of themselves and have already named it “Milkomeda.”
I know all this sounds confusing, galaxies careening across the sky on a collision course with each other. Here is a simple demonstration you can conduct in the comfort and safety of your living room. Amaze your family and friends with your knowledge of celestial mechanics.
All you need are two footballs with an A painted on one for Andromeda, and an MW on the other for MilkyWay. Place them on the floor 30 feet apart. Interestingly, this is pretty much the scale of the size and the distance apart of the two galaxies. All you have to do is sit down on your couch and watch closely. In 11,111,11 years the two galaxies will move one inch closer together.
That, my friends, is gravity at work, the same force that allows you to collapse into your easy chair after a tiring day of working in your yard.
If you want to see something closer to home, look for Saturn in the east just after it gets dark. At dawn, Venus and Jupiter are blazing in the east. Venus is the brighter one of the two.
Do not worry too much about falling into Andromeda. Three and a half billion years is a long time.
