January 17, 2006--The Martians Are Coming

You mean to tell me that we just learned about this last Monday? That there is a previously unrecognized galaxy, yes galaxy, with hundreds of thousands of stars heading our way? In fact, it is so close to our own galaxy that there is already evidence that it is merging with us.

Why was this story buried on page A15 of the NY Times? (See link below for the brief article.) This seems to me deserving of front page treatment. OK, if not above at least below the fold.

I am not an astronomer but it seems to me that this is a huge deal. Our galaxy is not that big in cosmological terms, even though it contains 200 billion stars and measures more than 100,000 light year across its breadth. The one they just discovered, which is in the process of merging with ours, is by no means that large (I think I should say Thank God for that), but what are the potential consequences of this merger?

I must hasten to add that this is not of that immediate a concern to us since it is now about 30,000 light years from Earth. (Recall that a light year is the distance light travel in a year and since its speed is 186,000 miles per second, if you do the math, you will see that this means our new galactic partner is still quite far away.

But since the astronomers who made this surprise discovery do not know the implications of this cosmic collision (for example will all this additional mass joining our galaxy affect gravitational forces on Earth?), I would suggest, if you are at all inclined, that you might want to stock up on canned foods and AAA batteries. Just to be safe.