Did Our Sun Capture Alien Worlds?

[Dover]

Did Our Sun Capture Alien Worlds?

Salt Lake City UT (SPX) Dec 01, 2004

Computer simulations show a close encounter with a passing star about 4 billion years ago may have given our solar system its abrupt edge and put small, alien worlds into distant orbits around our sun.
The study, which used a supercomputer at NASA's Jet Propulsion Laboratory in Pasadena, Calif., was published in the Dec. 2 issue of the journal Nature by physicist Ben Bromley of the University of Utah and astronomer Scott Kenyon of the Smithsonian Astrophysical Observatory in Cambridge, Mass.

Bromley and Kenyon simulated what would have happened if our sun and another star in our Milky Way galaxy had passed a relatively close 14 billion to 19 billion miles from each other a few hundred million years after our solar system formed.

At that time, our solar system was a swirling "planetary disk" of gas, dust and rocks, with planets newly formed from the smaller materials.

Imagine the encounter of two young solar systems by envisioning two circular saw blades brushing past each other while spinning rapidly. When they make contact, their outer edges are buzzed off by the other saw...cont'd

http://www.spacedaily.com/news/extrasolar-04zs.html

[soothsayer]

1. I still don't understand how things get near each other if the big bang

meant that all matter expanded outward, like blowing up a balloon and all the stars and stuff are on the surface of the balloon, moving outward and apart from each other. So how do they pass one another?

[Tace]

2. Good Point -- I Suppose It Could Have Been Gravitational Forces Pulling...

the two stars toward one-another. But, I'm not an expert. Cheers

[On the Road]

3. Intially, That Was True

But there were two waves of star formation and development ending in supernovas. The explosions meant that matter began flying in all different directions.

And at the same time, gravitation caused solar systems, black holes, and galaxies to form, all of which rotate and change the direction of large amounts of mass.

[Massacure]

5. The galaxy spins, and the inner solar systems spin faster than the outside

Plus you have the up-down wabble of the galaxy.

Think of it as a hammer thrower. The ball tends to wabble up and down, and the ball spins faster than the arm because it has more distance to cover.

[RawMaterials]

4. so wouldn't it be cool if there was an close alien planet that

is only the other side of space that has similar characteristics to our galaxy.

side note,
you wouldn't think this would come out of salt lake would you.

[Xithras]

6. There are several oddities in our system that this might explain

Why is Uranus on its side? Why does Pluto have such an odd orbit? What screwed up the rotational period of Venus? How did Sedna form so far out? Why did the water vanish from Mars 4 billion years ago? Why did the first life appear on Earth about the same time?

An intense gravitational disruption caused by a close pass with another star could explain these mysteries, and a few more.