It's called the Andromeda Galaxy, and it's twice the size of our Milky Way Galaxy. At least in terms of the number of stars in it. The galaxy seems to be on a collision course with ours, which may not be a good thing. The Andromeda galaxy is believed to be a cannibal (as they call it) that eats up other galaxies that come to close. There apparently is evidence for this, with small dwarf galaxies being gobbled up by Andromeda. But there is some good news.
Andromeda is about 2.5 million light years away from earth. It is traveling roughly at the speed of 70 miles per second, and is expected to be here in about 4.5 billion years. So we still have some time. But Ha! The Doomsday people were correct! They were just off... by about 4.5 billion years. Really not to bad when you think about it, (yes that's a joke).
For more information on the Andromeda Galaxy, or on the Collision with the Milky Way, click one of the links.
Now, it is just me, or is this news a little depressing? I mean, I'm pretty sure I wont live for another 4.5 billion years to see this collision come to pass. But, I still don't like this news. I started looking into this a little wanting to find some hope. Something that would say everything would be alright. What I found was what sounded like only a small chance that things could go very badly, and most likely the two would collide, likely form together, and we would become one giant happy galaxy, with our little solar system intact. Because of so much space in galaxies, planets and stars colliding is pretty rare.
I should have left it there with what little hope I had acquired. I went on to read that if all went well, it wouldn't matter, because our sun is going to boil this planet like an egg. At that point I put my happy face away, and brought back out my sad one. What makes this even sadder is our sun is expected to do this to us in about 1.4 billion years from now. Which means even less time. Good news is this sun problem is based on theoretical models that the sun was actually less bright, billions of years ago.
Something else that is interesting is, this theoretical sun problem creates a sort of paradox. Because it argues against observations of early earth's history of liquid water. It suggests that the sun being less powerful a few billion years ago, would not have been enough to sustain water for life to form, and as we know, it did. However, to compensate for this problem, it was theorized that there was more greenhouse gases in early earth's history, which would have allowed for the less powerful sun to sufficiently warm the planet, and thereby it's water.
Another problem to this theory is that sediments acquired from the Archean period were examined and found to not support the greenhouse gas hypothesis.
So in other words, I don't know if the sun is going to kill us or not, but hey, we still have that cannibal galaxy to look forward to if it doesn't. Yay for optimism!
I think I will end this post with a couple of questions. To anyone who happens to read this and knows more then I about the sun and galaxies, can you comment and say what are the chances of the sun cooking us and the galaxy eating us, and if the earth, and us have a chance to make it through all of this, alive.
I'm hoping we have a chance.
Hope you enjoyed this gloomy post. It is interesting... kinda, but at the very least, 1.4 billion years away. There's a silver lining, right?
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