> 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?

> On Apr 15, 6:46 pm, Lorentz 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...

> On Apr 15, 6:46 pm, Lorentz yahoo.com> wrote:

>> On Apr 14, 1:17 pm, Tom Hendricks 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?

>> ...

> "Tom Hendricks" att.net> wrote in message

>> 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.
>>

> Quite so. No meteorites have been identified so far as originating from
> Earth.