[meteorite-list] Planet V (for Five)

[Rob McCafferty]

Hello list

For those people recently who wereharping on about the
apparent disintegration of this list, this is an
example of the sort of gem which I find make it all
worth while.

I like a lot of what is in this post and wish I had
the celestial mechanics ability (and time too) to work
on it (With a healthy dollop of simulation programming
thrown in too)

I will restric myself to one thought to raise
regarding this topic and this is; Did all trace of
this planet disappear? Does anyone have any idea where
NWA3133 may fit into the picture?

Rob McCafferty

--- "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
wrote:

> Hi, List,
> 
>     With several stories being posted about the new
> research on lunar return samples showing that there
> was indeed a Late Heavy Bombardment with a sharp
> peak after a quiet period, instead of the Final
> Flurry 
> of an ongoing bombardment, I realized that the
> Planet V
> hypothesis put forward several years ago to account
> for the LHB also ties in with several other new 
> developments.
> 
>     The Asteroid Belt "should be" a zone of
> relatively
> similar objects in relatively circular, non-inclined
> orbits;
> that's what ALL the Solar System formation theories 
> would predict, despite the differing formation 
> mechanisms they propose.
> 
>     But, of course the "real" Asteroid Belt isn't
> like
> that. There are a wide variety of compositions, like
> iron asteroids (that could never have formed that
> far
> out), dry asteroids, wet asteroids, carbonaceous 
> asteroids, differentiated asteroids,
> non-differentiated
> asteroids, asteroids with diamonds, asteroids that
> smell
> like bubble gum... You name it.  In short, every
> oddball composition we know from meteorites.
> 
>     The SRI published a computer simulation earlier
> this year (about which Ron Baalke posted to The
> List) 
> that suggests the Asteroid Zone is full of objects
> that formed elsewhere in the Solar System (like iron
> asteroids) because they were ALL deflected there
> from
> other parts of the Solar System. It is silent on
> what
> did the deflecting, but the simulations seems to
> show
> that's the only way they could get there
> 
>     And, there are asteroid "families" with very
> distinctive
> eccentric and inclined orbits, grouped together. The
> "delta-V" required to drive asteroids into those
> orbits
> requires repeated close encounters with a body
> larger 
> than Mars (about 1 to 4 Mars masses). This
> observation
> is decades old, but no one has ever suggested,
> again,
> what did the deflecting, or when.
> 
>     Below is a news story about Chambers and
> Lissauer's
> Planet V (for Five) hypothesis, which they offer as
> an 
> explanation for the Late Lunar Bombardment, but it
> seems to me that the hypothesis may have "legs," as 
> they say, and that the other unexplained conditions
> described above offer some confirmatory
> implications.
> 
>     And, if you're looking for other unexplained
> facts
> to tuck into the envelope, there's the anomalous
> slow,
> backward rotation of Venus (a "day" longer than its
> "year"), for which repeated close encounters with a 
> large body has been suggested as a cause. Planet V?
> 
>     And last, there's the mantle-stripping Big Splat
> 
> on Mercury. We've always "assumed" that it took 
> place as early as our own Moon-forming Big Impact, 
> but it could have happened at 3.8 to 3.9 billion
> years 
> ago instead, the final outcome of Planet V's rogue 
> career. Guess we have to wait for that Mercury 
> Sample Return Mission to find out...
> 
>     Here's the only Chambers paper on the hypothesis
> that I could get to, for free anyway:
>
http://www.lpi.usra.edu/meetings/lpsc2002/pdf/1093.pdf
> 
>     There's an Australian paper that tries to
> duplicate
> the results of  Chambers and Lissauer, but can't.
> http://eo.ucar.edu/staff/dward/sao/dward617paper.pdf
> 
>     Its flaw is that it makes Planet V a puny little
> thing, about 5 to 8 times too small to do the job.
> But then, so does Chambers, because he wants 
> Planet V to end up crashing into the Sun, a silly 
> notion whose attractions I am blind to. I like the 
> Big Splat.
> 
>     But I understand his problem. If you're going 
> to stick another planet in the Solar System to 
> account for all these things, why, you have to get
> rid
> of it somehow since it doesn't seem to be around 
> any more!
> 
>     Mercury makes a perfectly good "hit man."
> 
> 
> Sterling K. Webb
>
----------------------------------------------------------
> 
>
http://www.space.com/scienceastronomy/solarsystem/fifth_planet_020318.html
> 
> Long-Destroyed Fifth Planet May Have Caused 
> Lunar Cataclysm, Researchers Say 
> By Leonard David, Senior Space Writer
> posted: 03:00 pm ET, 18 March 2002
> 
> HOUSTON, TEXAS -- Our solar system may have had a 
> fifth terrestrial planet, one that was swallowed up
> by the Sun. 
> But before it was destroyed, the now
> missing-in-action 
> world made a mess of things. 
>     Space scientists John Chambers and Jack Lissauer
> of 
> NASA's Ames Research Center hypothesize that along 
> with Mercury, Venus, Earth, and Mars -- the
> terrestrial, 
> rocky planets -- there was a fifth terrestrial
> world, likely 
> just outside of Mars's orbit and before the inner
> asteroid 
> belt.
>     Moreover, Planet V was a troublemaker. The
> computer 
> modeling findings of Chambers and Lissauer were
> presented 
> during  the 33rd Lunar and Planetary Science
> Conference, 
> held here March 11-15, and sponsored by NASA and the
> 
> Lunar and Planetary Institute.
>     It is commonly believed that during the
> formative years 
> of our solar system, between 3.8 billion and 4
> billion years 
> ago, the Moon and Earth took a pounding from space
> debris. 
> However, there is an on-going debate as to whether
> or not 
> the bruising impacts tailed off 3.8 billion year ago
> or if there 
> was a sudden increase - a "spike" -- in the impact
> rate 
> around 3.9 billion years ago, with quiet periods
> before 
> and afterwards? 
>     This epoch of time is tagged as the "lunar
> cataclysm" - 
> also a wakeup call on the cosmological clock when
> the 
> first evidence of life is believed to have appeared
> on Earth.
>     The great cover-up: Having a swarm of objects 
> clobbering the Moon in a narrow point of time would 
> have resurfaced most of our celestial next door
> neighbor, 
> covering up its early history. Being that the Moon
> is so 
> small, Earth would have been on the receiving end of
> 
> any destructive deluge too.
>     Moon-walking astronauts brought back a cache of 
> lunar material. Later analysis showed that virtually
> all 
> impact rocks in the "Apollo collection" sported
> nearly 
> the same age, 3.9 billion years, and none were
> older. 
> But some scientists claim that these samples were 
> "biased", as they came from a small area of the
> Moon, 
> and are the result of a localized pummeling, not
> some 
> lunar big bang.
>     There is a problem in having a "spike" in the
> lunar 
> cratering rate. That scenario is tough to devise.
> Things 
> should have been settling down, according to solar 
> system creation experts. Having chunks of stuff come
> 
> zipping along some hundreds of millions of years
> later 
> 
=== message truncated ===


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