[ExI] Life must be everywhere!

[Tomasz Rola]

On Sat, 14 Apr 2012, Kelly Anderson wrote:

> On Sat, Apr 14, 2012 at 3:00 PM, Tomasz Rola <rtomek at ceti.pl> wrote:
> 
> > Applying this to the impact calculator doesn't change much, however. A 1km
> > piece of ice falling down at 42km/s is going to burn me alive anyway.
> 
> Depends on how far away from you it hit, I suppose...

You can see it here:

http://impact.ese.ic.ac.uk/cgi-bin/crater.cgi?dist=100&distanceUnits=1&diam=1000&diameterUnits=1&pdens=1000&pdens_select=8000&vel=42.1&velocityUnits=1&theta=90&tdens=1000&wdepth=1000&wdepthUnits=1

I have placed "observer-me" at 100km distance from ground zero. I have 
tried to be good for impactor, by giving it a nice and soft place to land
(a 1000m deep water with rocky seabed).

> > Ten times slower speed required only means ten times longer exposure to
> > life killing factors.
> 
> But there could be a sweet spot in there somewhere... Life might take
> breaks along the way too... stop and reproduce on one rock before
> progressing to the next...

Well, not so much, I'm afraid. I agree that microorganisms are 
hard-to-kill bastards. OTOH, to reproduce they require some kind of 
friendly conditions, which, to my knowledge, don't include absolute zero 
temperature.

> > Again, in m/s - a speed comparable to fastest cars. So, whatever gets this
> > far is likely to be able to get away from the Sun, either directly or as
> > side effect of relatively benign asteroid clashes.
> 
> Even asteroid pass by could throw you out of the solar system... think
> of a little rock rotating clockwise, and a bigger rock going
> counterclockwise with a slightly larger radius. Upon crossing, the big
> rock has a slightly more elliptical orbit, and the small rock is
> ejected from the system entirely. No physical 'collision' is actually
> necessary, just an encounter.

Right.

> > Again, I don't think a natural panspermia is very likely to occur. And if
> > it does, then it's on a very limited scale. Still, a nice idea to think
> > about.
> 
> It would only have to happen once in a hundred million years for it to
> be the source of life's blueprint... Deep time changes the probability
> equations very much, making crazy seeming schemes like natural
> selection and panspermia actually seem quite a bit less crazy.

Ok, so let's see it from another end. Panspermia event could have happened 
many times and by probability, the most of ejecta ended in Solar System, 
including bodies we can more or less easily observe.

Yet, on all those bodies surveyed so far, even if they have been 
contaminated with life, during so many millions of years it didn't evolved 
into a form that would leave visible signs of existence... Such that we 
could recognise, that is.

Seems to me, if life can get away from this planet, it has hard time out 
there. Maybe some spores or similar forms survive intact, but their 
chances are dwindling as time goes by. It's like playing Russian roullette 
for millions years and they can fight entropy only by reproduction, which 
they cannot do in harsh environment.

Regards,
Tomasz Rola

--
** A C programmer asked whether computer had Buddha's nature.      **
** As the answer, master did "rm -rif" on the programmer's home    **
** directory. And then the C programmer became enlightened...      **
**                                                                 **
** Tomasz Rola          mailto:tomasz_rola at bigfoot.com             **