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RalofTyr
2008-Apr-04, 08:57 PM
The first bombardment was 4.5 billion years ago when the solar system formed, then, about 3.8BYA, there was a second bombardment of asteroids. So, what was the cause of the second?


Secondly, just how long would it take for our solar system to drift away from the nebula it formed it and away from its sister stars?

Hornblower
2008-Apr-04, 10:05 PM
The first bombardment was 4.5 billion years ago when the solar system formed, then, about 3.8BYA, there was a second bombardment of asteroids. So, what was the cause of the second?
Was there a lull? If so, can you quote some references?


Secondly, just how long would it take for our solar system to drift away from the nebula it formed it and away from its sister stars?The Sun would blow away the remnants of the nebula. I do not know how long that would take, and we probably do not have any way of telling what other stars, if any, formed a loose cluster at the time.

01101001
2008-Apr-04, 10:24 PM
The first bombardment was 4.5 billion years ago when the solar system formed, then, about 3.8BYA, there was a second bombardment of asteroids.

Which one was the Late Heavy Bombardment (according to Wikipedia (http://en.wikipedia.org/wiki/Late_Heavy_Bombardment) between 3.8 and 4.1 billion years ago)?

Hans
2008-Apr-04, 10:25 PM
That brings up a question, the nebula we formed in, do we know where its at or are we still in it?

01101001
2008-Apr-04, 10:31 PM
That brings up a question, the nebula we formed in, do we know where its at or are we still in it?

Our sibling stars are long gone, scattered. I'd expect the nursery to have dispersed, too.

Casus_belli
2008-Apr-05, 12:26 AM
Wasnt the late heavy bombardment caused by a gravitional resonance between Jupiter and Saturn?

I answer your question with a question because Im a bit of a thickie and am normally wrong. :D

RalofTyr
2008-Apr-05, 07:12 PM
Was there a lull? If so, can you quote some references?


A show on one of the science channels.




Which one was the Late Heavy Bombardment (according to Wikipedia (http://en.wikipedia.org/wiki/Late_Heavy_Bombardment) between 3.8 and 4.1 billion years ago)?

Yes.

John Mendenhall
2008-Apr-08, 06:57 PM
Anybody ever look at the possibility of the solar system drifting through another stellar nursery as the source of the late heavy bombardment? Should be a testable idea, if the late heavy impactors are not of solar system composition.

RalofTyr
2008-Apr-11, 06:01 AM
Anybody ever look at the possibility of the solar system drifting through another stellar nursery as the source of the late heavy bombardment? Should be a testable idea, if the late heavy impactors are not of solar system composition.


Perhaps they didn't just drift through, but a near (1ly) miss, which caused all the Oort cloud material to fall inward?

Another theory suggests that's when Sol's second star was ejected.

What gets me, is that the period between bombardments, is when Mars had an early Earth-like environment.

Eroica
2008-Apr-11, 02:53 PM
What Caused the Second Bombardment?
I've heard two theories:

1: Jupiter perturbed the young planetesimals accreting in the asteroid belt, preventing a planet from forming there and scattering much of the debris, which collided with the terrestrial planets and the Moon.

2: Neptune's migration carried it from about 15 AU out to 30 AU, into the Kuiper Belt. This scattered Kuiper Belt Objects into the inner Solar System, causing the Late Heavy Bombardment.

Essan
2008-Apr-11, 03:06 PM
Oddly enough only came across this by chance when watching a Nat Geo documentary earlier this week

Origin of the cataclysmic late heavy bombardment... (http://www.nature.com/nature/journal/v435/n7041/pdf/nature03676.pdf)