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Science Forum Index » Bio Evolution Forum » Panspermia Catch 22
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| Tom Hendricks |
 Posted: Mon Apr 14, 2008 7:17 am |
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On the one hand, a planet needs enough gravity to hold
in the necessary gases to have the atmosphere that
leads to life.
On the other, 'there is probably not enough energy in
the most violent volcano eruption to eject gravel size
or larger rocks out of the gravity well of a
terrestrial planet and into space." 'Life As We Do Not
know It.'
Therefore it is highly unlikely for a planet with the
necessary gravity to begin life, to also eject that
life into space.
Comment? |
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| J.A.Legris |
| Posted: Tue Apr 15, 2008 1:46 pm |
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On Apr 14, 1:17 pm, Tom Hendricks <tom-hendri...@att.net> wrote:
Quote: On the one hand, a planet needs enough gravity to hold
in the necessary gases to have the atmosphere that
leads to life.
On the other, 'there is probably not enough energy in
the most violent volcano eruption to eject gravel size
or larger rocks out of the gravity well of a
terrestrial planet and into space." 'Life As We Do Not
know It.'
Therefore it is highly unlikely for a planet with the
necessary gravity to begin life, to also eject that
life into space.
Comment?
Forget volcanoes. Life may have arisen out there, under water or
underground in severe conditions of heat, pressure or salinity,
yielding tough little critters. One good impact from a meteor could
have ejected large amounts of material into space where it would have
freeze-dried until finding a new home far, far away.
--
Joe |
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| Lorentz |
| Posted: Tue Apr 15, 2008 1:46 pm |
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On Apr 14, 1:17 pm, Tom Hendricks <tom-hendri...@att.net> wrote:
Quote: On the one hand, a planet needs enough gravity to hold
in the necessary gases to have the atmosphere that
leads to life.
On the other, 'there is probably not enough energy in
the most violent volcano eruption to eject gravel size
or larger rocks out of the gravity well of a
terrestrial planet and into space." 'Life As We Do Not
know It.'
Therefore it is highly unlikely for a planet with the
necessary gravity to begin life, to also eject that
life into space.
Comment?
Although I am not a believer in universal panspermia, the
probability of life propagating within this solar system to other
planets does not seem impossible. Your argument has a lot of flaws. I
will give you my version of the theory proposed by scientists in the
Jet Propulsion Laboratory of NASA. If anyone at JPL sees this and
thinks I got it wrong, he should protest.
A bolide collision can produce the necessary energy to project
small objects into space. We know this is true because of tekatites
from the moon and Martian rocks found on earth. The heat and shock
would be distributed unevenly, so there may be part of the ejected
material with living microorganisms. We know this again because of
Martian rocks with gaseous residues. Some microorganisms have a
dormant state which will allow a few of them to survive the millions
of years to fall to a new planet. Bacterial endospores are common
microorganisms on earth. If the organisms are deep in the material
that falls, some microorganisms may survive. Basic physics. Small
bodies can't burn up due to air friction since they reach terminal
velocity too fast.
I think the individual microorganism has a small if not
astronomically small chance of surviving all this. However, a small
amount of material can contain a lot of microorganisms. The
probability of one or two microorganisms surviving all this out of all
the microorganisms in a livable planet may not be so improbable.
I think NASA has a plausible program for investigating this
possibility. And I don't think a few manned space missions will do it.
Hundreds of tiny robotic missions is the way to go.
The Hoyle panspermia idea is nonsense. |
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| Tom Hendricks |
| Posted: Wed Apr 16, 2008 7:25 am |
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On Apr 15, 6:46 pm, Lorentz <drosen0...@yahoo.com> wrote:
Quote: On Apr 14, 1:17 pm, Tom Hendricks <tom-hendri...@att.net> wrote:
On the one hand, a planet needs enough gravity to hold
in the necessary gases to have the atmosphere that
leads to life.
On the other, 'there is probably not enough energy in
the most violent volcano eruption to eject gravel size
or larger rocks out of the gravity well of a
terrestrial planet and into space." 'Life As We Do Not
know It.'
Therefore it is highly unlikely for a planet with the
necessary gravity to begin life, to also eject that
life into space.
Comment?
Although I am not a believer in universal panspermia, the
probability of life propagating within this solar system to other
planets does not seem impossible. Your argument has a lot of flaws. I
will give you my version of the theory proposed by scientists in the
Jet Propulsion Laboratory of NASA. If anyone at JPL sees this and
thinks I got it wrong, he should protest.
A bolide collision can produce the necessary energy to project
small objects into space. We know this is true because of tekatites
from the moon and Martian rocks found on earth. The heat and shock
would be distributed unevenly, so there may be part of the ejected
material with living microorganisms. We know this again because of
Martian rocks with gaseous residues. Some microorganisms have a
dormant state which will allow a few of them to survive the millions
of years to fall to a new planet. Bacterial endospores are common
microorganisms on earth. If the organisms are deep in the material
that falls, some microorganisms may survive. Basic physics. Small
bodies can't burn up due to air friction since they reach terminal
velocity too fast.
I think the individual microorganism has a small if not
astronomically small chance of surviving all this. However, a small
amount of material can contain a lot of microorganisms. The
probability of one or two microorganisms surviving all this out of all
the microorganisms in a livable planet may not be so improbable.
I think NASA has a plausible program for investigating this
possibility. And I don't think a few manned space missions will do it.
Hundreds of tiny robotic missions is the way to go.
The Hoyle panspermia idea is nonsense.
But note your two examples small objects from the Moon or Mars -
both with less gravity than the earth. I suggest that neither had the
necessary atmosphere needed to start life. Thus you need bigger
planets
to start life, and bigger planets have more gravity and even less
chance
to eject life to space.
Perhaps it is possible - for instance if life had begun before the
bombardment phase - but I still think it is highly unlikely. |
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| Lorentz |
| Posted: Wed Apr 16, 2008 7:18 pm |
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On Apr 16, 1:25 pm, Tom Hendricks <tom-hendri...@att.net> wrote:
Quote: On Apr 15, 6:46 pm, Lorentz <drosen0...@yahoo.com> wrote:
But note your two examples small objects from the Moon or Mars -
both with less gravity than the earth. I suggest that neither had the
necessary atmosphere needed to start life. Thus you need bigger
planets to start life, and bigger planets have more gravity and even less chance to eject life to space.
I have some news that confused me when I learned it. There is no
planet, no matter how massive, that can hold a gaseous atmosphere
forever. If you go do a fluid statics calculation using the Newton
gravity formula assuming a spherical planet, it turns out that gas
diffuses from every planet. What has prevented earth from losing its
atmosphere is emission of gases from volcanoes. Your correlation of
planet mass with atmospheric density is weak, although partly valid.
1) Most planets don't have large moons. Our atmosphere is thinner than
it would be if it didn't have a disproportionately large moon. Our
moon launches gases into space. Look at Venus. It has no moon, and an
atmosphere which is much thicker than the earths. A small planet
without a moon, but with active volcanism, may have an atmosphere just
as thick as earth. However, it would have a small escape velocity.
2) Most of the gases on earth are dissolved in the mantle and core,
and so are locked from the atmosphere. Volcanoes release the gas
slowly. However, the same would go for even small planets. Even a
small rocky atmosphere can hold onto an atmosphere a long time if the
small gas were tectonically active. Many of the moons of the gas
giants have significant atmospheres, supported by significant
volcanism.
3) Gas giants have more atmosphere, and so will lose their entire
atmosphere more slowly. Livable regions will be near at the margins. A
good collision could toss up material from these edges. The escape
velocity at the edge of the atmosphere may be smaller than the escape
velocity near the surface. Some of the microorganisms will be near the
edge of the atmosphere.
4) Underground oceans and atmospheres. Of course we have those planets
that may have a liquid water ocean trapped under ice, with internal
heating. Europa may have such an ocean. The canonical surface doesn't
have to have an atmosphere. The ice would keep it in.
5) There is no sharp boundary between a massive planet and a light
planet in terms of escape velocities. The escape velocity on earth is
about 7 miles per second, the escape velocity of Mars is about 4 miles
a second. If that bolide blasted thousands of Martian rocks in space,
the same bolide could probably blast hundreds of earth rocks into
space. |
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