Bill's Topics

Another very troubling event I have been reading on-line about is the issue of our closest spiral galaxy neighbor, Andromeda, crashing into the Milky way and destroying the earth in the year 2012.

The Facts

The Andromeda Galaxy, or M31 (Messier Object M31) was once thought of as a 'cloud' in space - a nebulae.  Today, with much more powerful telescopes and much better measuring tools, we know that M31 is a galaxy of billions of stars that lives 2,500,000 (two million, five hundred thousand) light years away.  In miles, this is 1,466,300,000,000,000,000 miles into space.  I don't even know how to 'pronounce' this number, but you could probably say 1.466 million million million miles away.  In an automobile, driving at 60 miles an hour, it would take you 27,898,000,000,000 quadrillion years to get there.  It's not just 'around the block'.

So, at this great distance, even at the speed of light (nothing can travel as fast or faster than the speed of light), it would take the Andromeda galaxy two million, five hundred thousand years to reach our galaxy, the Milky Way.

Today, the Andromeda galaxy is traveling towards the Milky Way (and the Milky Way towards Andromeda) at about 87 miles per second.  Gravity does accelerate objects as they get closer, so by all estimates, the Andromeda galaxy and Milky Way Galaxy will collide in about 4.6 billion years.

Will we be here when the fireworks start?

Let's sit back and think about this for a few minutes.

The earth, is about 4 and a half billion years old.  This is almost the exact amount of time it will take the Andromeda galaxy to reach the earth.  But, this really doesn't matter since we are talking about the future and not the past.

It is estimated that our Sun will turn into a red-super giant star in about five billion years or less (perhaps 4.5 billion years) and then will fizzle away as a white dwarf star.  It is estimated that life on the earth will become extinct before this as the sun is becoming hotter as time moves forward, so in perhaps, 4 billion years, the earth will not be able to support life any longer because of the temperature increase.

So, do we need to worry about the Andromeda galaxy colliding with the Milky Way?  Probably not as the earth won't even be here when it does and we surely will not be here.

But, what if humanity finds it can travel through space and colonize other planets.  What then?

What will actually happen?

So, let's say the human race migrates out into space and colonizes other worlds.  Let's say for a moment that we are able to keep from killing ourselves in the next four and a half billion years and we get to see the Andromeda galaxy collide with the Milky Way galaxy.  What will we see?

The distance between the stars is enormous, and there is no reason to believe it is any different in the Andromeda galaxy.  For example, our closest neighbor is 4.4 light years away (Alpha Centauri).  That is 25,809,000,000,000 miles away.  A star like the sun is normally about 870,000 miles in diameter.  This means that the distance between the sun and our closest stellar neighbor is 29,665,517 times greater than the size of our sun.  Or to put it a little differently, you could fit 29,665,517 stars between our sun and our closest neighbor.   That's a whole BUNCH of stars, and the stars in a galaxy are just not packed that closely together.

So, in all reality, as the two galaxies (Andromeda and the Milky Way) collide, most stars will just pass by each other, most, probably not even seeing others as they do because of their distance.  If you are still alive at that time, it will be a beautiful site, and I hope that reincarnation is true because I would LOVE to see the show!

What will be the Result?

Once it's all over, the two galaxy's, together, will form what is commonly known as an elliptical galaxy.  Not as beautiful, but just as functional.