Thanks a lot to everyone who gave me an answer! I hoped that there were some
sharp idea about the chodrules and the CAI's but I have understand that
there are just tons of doubts :(
Best regards!
<>X<>X<>X<>X<>
Francesco Moser
IMCA #1510
----- Original Message -----
From: "MEM" <[email protected]>
To: "ZZ ML Meteorite-List" <[email protected]>; "Francesco
Moser" <[email protected]>
Sent: Thursday, October 01, 2009 9:55 AM
Subject: Re: [meteorite-list] CAI and chondrules
I've my own collection of ideas as to how chondrules developed but will
save them for later. As to CAIs and their presence in carbonaceous
meteorites. A list member and I had this discussion some time ago and the
answer may lie in a process in the "T-Tauri" stage of stellar evolution.
When the T-Tauri protostar goes thermonuclear it loses a mass through a
high solar wind output which sweeps a lot of the remaining unaccreted
debris from the inner solar system--we believe. This is the foundation
for our ability to develop isotopic curves of regions based on distance
from the sun and explains the rocky inner planets and the gas giants much
further out in the solar system. This probably is a player in chondrule
formation. CAIs are dated to about 2 million years older.
Prior to the hydrogen fuel-burning stage, there was an ongoing fission
process which is the likely source for the short-lived isotopes such as
26Al. While I can't lay my hands on the link, I recall some diagrams of a
particular phase of T-Tauri accretion where the dynamics were such that
even though the solar disk was being spun into a flat, thin, rotating
disk, the poles of the proto-sun were ejecting major mega streams of
lighter, probably charged particles-- mainly such as calcium, aluminum,
carbon, helium, etc. The particle streams resembled fountains spraying
very high speed particles many many AUs up and out of the plane of the
ecliptic into two giant hemispheres.
If true, this tends to explain the Ort cloud formation and how CAIs were
available for inclusion in cometary-like carbonaceous meteorites along
with younger chondrules. It explains how CAIs predate the sun's fusion
stage and how they were able to skip the mega solar winds generated when
the sun kicked over to fusion from fission. Comets forming inside the Ort
Cloud but outside the ecliptical plane my be devoid of chondrules
(possible example: Tagish Lake)
1) supernova
A super nova is theorized to be the catalyst for compressing enough dust
close enough for gravity to take over and condense the early initial solar
disk getting things spinning into a disk.
2) few time later CAI formation
Yes but a long time later, possibly explained under the T-Tauri pre-fusion
stage during the collapse of the solar disk.
3) at the same time collapse of nebula
Yes but probably well after the accretion stage was under way.
4) 2My later condrule formation.
Yes again
5) at the same time proto-sun and proto-planetary formation
Probably in connection with the fusion to fusion change-over and during
the interval before mega-solar wind swept out the lighter elements from
the inner solar system and stopped chondrule formation.
6) ...
There were probably at least 6 additional Mars sized planets else
planetary centers of accretion and some theorize 30 or more. One was
accounted for by our moons formation, another knocked Uranus on its side
one or more contributed to the asteroid belt. Someplace in the sequence
comets formed outside the mainstream goings on in the solar disk/system it
self.
Elton
--- On Wed, 9/30/09, Francesco Moser <[email protected]> wrote:
From: Francesco Moser <[email protected]>
Subject: [meteorite-list] CAI and chondrules
To: "ZZ ML Meteorite-List" <[email protected]>
Date: Wednesday, September 30, 2009, 5:37 PM
Hello!
I take a look on wikipedia about CAI and chondrules, but I
have still some doubt.
http://en.wikipedia.org/wiki/Calcium-aluminium-rich_inclusion
http://en.wikipedia.org/wiki/Chondrule
What prompted the formation of CAI? and what's caused the
formation of chondurles???
The supernova gave the energy for the formation of CAI and
for the collapse of the solar nebula?
Some other energy source, still unknow, 2 million years
later molten the material which formed the chondrules? But
wich type of energy source?
Is correct this time line?
1) supernova
2) few time later CAI formation
3) at the same time collapse of nebula
4) 2My later condrule formation
5) at the same time proto-sun and proto-planetary
formation
6) ...
Thanks a lot!
Best regards!
Francesco Moser
IMCA #1510
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