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| Galaxies VV340 North and VV340 South approaching collision. |
But, now we have another crash to comtemplate: our Milky Way galaxy, which is the home of our solar system, is on a collision course with the larger Andromeda galaxy, similar to that of the two galaxies pictured. The collision will completely disrupt both galaxies, flinging star systems hither and yon before the two galaxies coalesce into a larger galaxy.
That's the bad news. The good news is that we have a couple billion years to get ready for this, so don't run out for bread and milk just yet. The other good news is that in spite of the huge population of stars in the two galaxies, the distances between individual star systems is so vast that stellar collisions will be rare, if any occur at all. A star like the sun is approximately a million miles in diameter. The closest star system to us is over 25,000,000 times that diameter, a lot of room for misses. And that's just one star. All the others are farther.
The 2 galaxies shown are about 450 million light years from us, about 2.7 sextillion miles (2.7 x 10^21 for you math whizzes). At their present rate of progression, their collision will start in about a million years. Assuming they are the size of our own Milky Way galaxy each is about 100,000 light years (600 quadrillion miles) in diameter, and contain about 100 billion stars each. The topmost galaxy is seen edge-on, while lower one seen flat-side-on.
Actually, my report that the collision of galaxies VV340 North and VV340 South will occur in a million years is misleading. It will be visible to our descendents in a million years, but in actual fact, the collision occurred about 449 million years ago. As the galaxies are 450 million light years from us, light takes 450 million years to traverse that distance. The universe is a big place.
Whew! At least I get to watch the last season of House!!
ReplyDeleteNot necessarily. There is yet another rapture coming October 21, and if you get LEFT BEHIND, there is the threat by Anonymous to "kill" FaceBook on November 5. If that happens, most likely the world will end the same day.
ReplyDeleteAs to the galaxy collision, when I was about six I saw a movie that began with scientists on Earth watching an explosion in deep space. A few days later, the aliens began landing in NY and LA.
ReplyDeleteI was already pretty savvy about the vast distances in space so asked my father how they got here so quickly. He explained that the explosion had occurred millions of years before and the aliens had been traveling all that time to reach Earth (he could be like Calvin's dad in Calvin & Hobbes when he wanted to), so I figured that these were pretty old aliens. I was never much impressed with the Old Testament patriarchs who lived only a few hundred years after that.
Interesting about time and distance: we look out into space, we look back in time. We can see all the way back to the time light first shone through the universe, called the Recombination by cosmologists. We still see that light, now stretched to microwaves, showing up as a small part of the static visible in an old-style TV screen, and a bit of the static on radios.
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