[meteorite-list] Did Life Arrive Before the Solar System EvenFormed?

From: Marc Fries <m.fries_at_meteoritecentral.com>
Date: Thu May 5 10:49:49 2005
Message-ID: <1162.69.140.92.248.1115304536.squirrel_at_webmail.ciw.edu>

Howdy All

   I don't believe that interplanetary, much less interstellar, transport
of viable microorganisms is possible. Keep in mind that extremophiles
are called that because they live in environments that are extreme
compared to what we live in. They are still limited in what they can
withstand, and all of them still require water, an atmosphere, and
protection from radiation. Placing them aboard a rock in the cold,
radiation-hard, vacuum of space doesn't provide any of these (except
for UV protection, and only if it's large enough). As a demonstration
of this, try placing any type of extremophile - psychrophile,
thermophile, radiodurans, etc - in the low-vacuum imaging chamber of an
environmental SEM. You get a picture of the cellular wreckage that
results.
    I'd disagree with your assertion that UV radiation is a rarity in
space, and cosmic radiation is rarer. UV is common and intense via
the sun, and the residency time of a particle in space is very long.
It is reasonable to expect a high cosmic ray flux and much higher UV
flux for the thousands of years that even an interplanetary tranfer
would require. (and the highest known tolerable temperature for
microbes is something like 140 C, not 600)
    And even if we set all that aside and say that
interplanetary/interstellar transport is possible, it still doesn't
answer the question of how life arose. It just moves the starting
point somewhere else and muddies up the in-between with an impossible
transport mechanism. I think it is likely that life arises just about
every time that the conditions are right. Evidence suggests that life
arose on Earth very soon after environmental conditions became
tenable; it is reasonable to expect that such a thing happens
elsewhere. It is entirely concievable to me that life arose on Mars
and has retreated deep into the crust, and that life exists on Europa.
 I don't think that transport is necessary for this to occur.
   Thanks for the good debate!

Cheers,
MDF

> Hi, Humbug and All,
>
> Humbug right back. You'll notice the press release so politely
> mentions
> that <quote> previous studies have looked into the likelihood that
> life-bearing
> rocks (typically exceeding 10 kgm's in weight) play a role in the spread
> of life
> within isolated planetary systems and found "the odds of both meteoroid
> and
> biological transfer are exceedingly low." <unquote>
> They are referring to what is (was?) considered the definite work on
> the
> subject by impact authority Jay Melosh:
> <http://www.lpl.arizona.edu/~jmelosh/InterstellarPanspermia.pdf>
> who basically said "not in the lifetime of the galaxy" or in other words,
> Humbug!
> Melosh's work was an impressive piece of computer simulations. The
> problem
> with computer simulations is that you have no idea if you're right or
> tip-toeing
> through the daisies without a reality check.
> At the time of its publication, I posted a fine cranky piece to the
> List,
> pointing out that AMOR radars all over the world (but particularly New
> Zealand
> with their lovely view of the South Pole) detect objects that have to have
> come
> from outside the solar system all the time. Granted, they are less than
> 1% of
> the tens of thousands detected per year, but that's still one hell of a
> lot of
> interstellar meteoroids!
> Yes, granted they are small grains, not 10 kilogram transports, but do
> you
> really think that bacteria chicken out and cancel their flight plans if
> the
> plane doesn't weigh at least 10 kilograms? "You're not getting me up
> there in
> that thing -- why that rock doesn't weight one kilo much less ten!"
> If there are frequent small interstellar particles, then less
> frequently
> there are larger ones, and even less frequently there are even larger
> ones, and
> so on. It's called the "power law of mass distribution." And it means
> that all
> those computer simulations really were only a walk through the daisies...
> Extremophiles just love extremes. Radiodurans clogs up the core of
> nuclear
> reactors, basking without sun block or dark glasses in a flux that would
> kill
> you in five seconds or less. There are extremophiles that love the
> pressure
> miles into the Earth's mantle, extremophiles that smack their chops at the
> chance to dine on almost any toxic substance known, extremophiles that
> catch
> cold if they're not swimming around in 600-degree fluids. Anything or
> anywhere
> nasty, there's some little bug that loves it, needs it, and just can't
> live
> without it.
> Commonly, you might think nothing could survive so long or hard a
> journey.
> I point you to a simple example of survival by endurance: the common
> tick.
> Ticks are complex animal organisms just like we are, not hard durable
> one-cellers. But once a momma tick embeds her dormant offspring in the
> bark of
> a tree limb, the young tick will persist in a state indistinguishable from
> death
> for 10 years, 30 years, 50 years, 80 years (no one really knows how long),
> until
> a sweaty warm-blooded mammal walks under the tree and a few molecules of
> its
> pheromones waft up to the tree limb.
> In the 0.5 to 1.0 second that passes from the time your sweaty
> forehead
> moves under the tree limb and your scent starts up slowly toward the limb,
> the
> 50-year "dead" tick will detect those molecules from its burial site
> inside the
> tree bark, wake up from its "death," get every organ pumped up and
> working, bore
> through the bark of the limb, and drop straight down with unerring aim
> onto the
> back of your neck or into your hair if he's fast enough, ready to start
> drinking
> your blood!
> If the tick misses you, it's dead. It won't get a second shot and
> hasn't
> the strength to try anything else. If you describe this strategy to most
> people
> without telling them it's the life of a tick, they will just shake their
> heads
> and say, "Impossible." But, since there certainly seem to be more than
> enough
> ticks in this world, this "impossible" scenario must succeed.
> So, I figure that a living (though possibly dormant) cell riding in a
> dust
> mote that's zipping through the 3 K vacuum and dodging the rare UV photon
> and
> cosmic rays (even rarer), is a distinct biological option, no more amazing
> or
> unlikely than that tick. I see him now. He's drifting along, sound
> asleep in
> his recliner, and waiting for that soft landing in the atmosphere of a
> planet he
> can eat. Yum. Crunch. And before you know it, there's another blue
> world with
> a poisonous oxygen atmosphere...
> Since the Universe is almost exactly three times older than the solar
> system, this has likely been going on for a long, long time, and I figure
> the
> whole place is probably thoroughly infested with ubiquitous life, life,
> life.
> The dam things are everywhere. And it's pointless to call an
> exterminator.
> You'll never get rid of them.
>
>
> Sterling K. Webb
> --------------------------------------------------------
>

-- 
Marc Fries
Postdoctoral Research Associate
Carnegie Institution of Washington
Geophysical Laboratory
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Washington, DC 20015
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FAX: 202 478 8901
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Received on Thu 05 May 2005 10:48:56 AM PDT