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When Worlds Collide



 
 
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  #1  
Old October 5th 08, 06:23 PM posted to sci.space.policy
Pat Flannery
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Default When Worlds Collide

Two Earth-sized planets in orbit around a double star... then, one
day...KA-BLEWEY!
http://www.astrobio.net/news/index.p...ticle&sid=2886

Pat
  #2  
Old October 6th 08, 12:34 PM posted to sci.space.policy
[email protected]
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Posts: 1,465
Default When Worlds Collide

On Oct 5, 1:23*pm, Pat Flannery wrote:
Two Earth-sized planets in orbit around a double star... then, one
day...KA-BLEWEY!http://www.astrobio.net/news/index.p...ticle&sid=2886

Pat


This is interesting. Two stars come to orbit one another very
closely. So, closely that astronomers thought it was one star. They
wondered about the excessive dust. Two planetary systems orbiting in
opposite directions in nearly the same plane. This would be like
driving down the wrong side of the highway. Its only a matter of time
before a collision! Then of course, debris flies off in all
directions, showering the other planets. Eventually, the angular
momentum of both systems cancel, and it all falls down!

Sheez.

At the end they note that even small collisions have dire consequences
- yeah.

Here's what would happen if a small Ceres sized object struck Earth

http://www.youtube.com/watch?v=yYgEwXWilUc

Of course, the moon was formed when the proto Earth - smaller than
today's Earth - collided with a mars sized object.- moving in the same
direction. Moving in opposite directions, both planets would have
been obliterated.

Moving in the same direction, two planets would have hit one another
with a 10 km/sec speed, which would be less than their escape velocity
- leaving debris that would eventually fall back together - leaving
perhaps a large moon. Off axis collisions would cause the objects to
spin wildly as the careened off one another.

Moving in opposite directions in the same plane the two planets would
hit one another with 70 km/sec speed, ejecting material across the
ecliptic.- off axix collisions would have caused objects to spin even
more wildly - tearing apart from the spin.
  #3  
Old October 6th 08, 03:33 PM posted to sci.space.policy
Martha Adams
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Posts: 371
Default When Worlds Collide

wrote in message
...
On Oct 5, 1:23 pm, Pat Flannery wrote:
Two Earth-sized planets in orbit around a double star... then, one
day...KA-BLEWEY!http://www.astrobio.net/news/index.p...ticle&sid=2886

Pat


This is interesting. Two stars come to orbit one another very
closely. So, closely that astronomers thought it was one star. They
wondered about the excessive dust. Two planetary systems orbiting in
opposite directions in nearly the same plane. This would be like
driving down the wrong side of the highway. Its only a matter of time
before a collision! Then of course, debris flies off in all
directions, showering the other planets. Eventually, the angular
momentum of both systems cancel, and it all falls down!

Sheez.

At the end they note that even small collisions have dire consequences
- yeah.

Here's what would happen if a small Ceres sized object struck Earth

http://www.youtube.com/watch?v=yYgEwXWilUc

Of course, the moon was formed when the proto Earth - smaller than
today's Earth - collided with a mars sized object.- moving in the same
direction. Moving in opposite directions, both planets would have
been obliterated.

Moving in the same direction, two planets would have hit one another
with a 10 km/sec speed, which would be less than their escape velocity
- leaving debris that would eventually fall back together - leaving
perhaps a large moon. Off axis collisions would cause the objects to
spin wildly as the careened off one another.

Moving in opposite directions in the same plane the two planets would
hit one another with 70 km/sec speed, ejecting material across the
ecliptic.- off axix collisions would have caused objects to spin even
more wildly - tearing apart from the spin.

===================================

I just watched the video, it was interesting. In fact,
there are very many such scenarios that could happen
and sooner or later, one of them certainly will. The
processes that made this solar system are certainly
not going to stop just because we are here at this
time.

Details! Astronomically speaking. That is
because our solar system's mechanics are chaotic, not
stable, perfect, and eternal. If you add to this the
business of selling arms, very profitable to the makers
of the arms but intensely destabilizing to everyone else,
and the governments and even large institutions who can
now build their own bacteriological and nuke weapons,
it all adds up to practical certainty that at a point,
it all comes down. All our world.

That's why I'm advocating to spend a little of that
military money somewhere else: to build settlements
off-Terra, enough of them to amount to an economic
system that can survive if Terra doesn't. This would
be a winner to do in at least three ways:

1) Lots of brownie points to whoever's language is the
human language of the Solar System. ...Mandarin
Chinese?

2) I don't think the Ceres scenario features human
survivors. Very many of those don't. Except, if we
have those settlements and economic network out there,
off-Terra. Thus off-Terra settlement and economics
are a very good insurance. This insurance is today
accessible and for the past 50 years. Kind of bad
to be doing without it for ...whatever reasons.

3) Movement into space could give us a frontier again.
Presently, we've exhausted our local resources for
frontiers, or made them into war zones. The new
frontiers could provoke a needed renaissance, large
change from the present increasingly autocratic way
of things, so that *maybe* plain rationality could
come back into governmental styles. Then the system
crash so easily foreseen, could be relegated to
horror stories for those who like reading
constructions of deviant history. And the astro
crash may be inevitable but it's (probably) very
much farther away than what our governments are up
to.

I hope for reason again here in America. But one of
the candidates is truly remarkable: she's a living
proof that "virulent" and "mundane" can indeed both
co-exist in one single person. Further, she seems
to be a millennialist: she believes the Christian
'Last Days' and 'Rapture' will happen *in her life
time*. Imagine her as President. With her thumb on
the nuclear Big Red Button. Anyhow, I'm not seeing
a lot of good sign for the future.

Titeotwawki -- mha [sci.space.policy 2008 Oct 06]




 




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