Your Identity/Life -- How, Why
-- Answers on Titan?
(Top Posts - Science - 011505)
assignment of personal pronouns, like "I",
"you", "we", "them", and "us",
was a consequence
of an evolved being possessing the sound utter-
ance capability by which those expressions, in
innumerable languages, were developed.
matter which eventually became the being
that you are, that is best understood as a natural-
istic series of events in an all-but infinite if not infi-
nite expanse of time and space.
way in which you function is naturalistically
understandable up to a point, with some mysteries
inability of any of us to explain all that is, all
that ever was, and all that ever will be, not surpris-
ing what with the way we arrived here, genetically-
inclined to be what we are, the only knowledge
present being whatever our genes possess, and
whatever was learned prior to our arrival + whatever
we've learned since each of us has arrived.
course, much of that knowledge has been lost,
in the last few thousand years, due to deterioration
both natural and imparted by humans who sought
to destroy rather than preserve.
to extinctions, mass extinctions, much of
the genetic record is forever lost. So much is lost,
that it's difficult to figure out how the spark of life
got started in the first place, as earth was a far dif-
ferent environment when the replication modality
was initiated. Here's a perspective on that from a
recently televised broadcast of "Discoveries This
The Beginning of Life?
Welcome to the University of Arizona,
where desert gardens blossom with life, and
scientists grapple with a thorny question. How
did this planet, which began as a sterile lifeless
rock, become the home to every living thing we
know of in the universe?
Jonathan Lunine (planetary scientist, University
of Arizona): We would like to understand how life
began, so one would expect that looking at the
earth, the earth being the only place we know of
as having life, would be the perfect way to do it.
It's actually the worst way to do it.
According to Jonathan Lunine, earth is
the worst place to learn how life began because
here on earth, all the organic molecules available
have already been processed and re-processed
by living things, leaving no trace of what came be-
Jonathan Lunine: Very much like the perfect
crime in which all of the evidence of a crime has
been erased, life has erased the signatures of its
origin on the earth. So if we want to understand
the origin of life in a natural environment, we need
to go somewhere else in the solar system where
organic molecules and organic chemistry is going
on, but life is not present.
For Lunine, that somewhere else could
be Titan, the giant moon of Saturn. Lunine is an
interdisciplinary scientist with NASA's Cassini mis-
and the European-built Huygen's probe, which
together are exploring Titan up close for the first
His goal is to discover whether there's anything on
Titan that could reveal how life began on earth, and
his search begins with Titan's atmosphere.
Jonathan Lunine: Titan's atmosphere is both
very dense and also very extended. Now the primary
gas in the atmosphere is nitrogen, as in the case of
the earth, but because the conditions are so cold ...
there's no water vapor in Titan's atmosphere.
there is methane vapor, and methane is
the simplest organic molecule. It is the starting
point for any kind of chemistry leading toward life.
The presence of methane gas in Titan's
atmosphere makes possible the same chemical
that are the basis for life on earth. Like
the bottom rung in a ladder, it's the first step toward
a whole series of more complicated molecules col-
lectively known as hydrocarbons.
... What scientists are hoping to see on Titan is a
preserved version of the scaffolding of life, the same
scaffolding that allowed living forms to spring up on
earth. That means sampling Titan's atmosphere dir-
ectly, to see what molecules are present there, and
landing on the surface to see where that material
ends up. ...
... It seems strange to search for a basic truth so
far from home. But on the hidden surface of Titan,
we may yet learn how life came to be. Life that on
earth eventually reached the level of a technological
civilization, and produced people like Jonathan Lu-
nine who want nothing more than to know what life
in the universe is all about.
for what resides outside our particular space-time
continuum, only theoretically explorable, thus far.
for what resides apart from earth, significant prog-
ress has been made in studying our Moon, and Mars
(and recently, a moon of Saturn, Titan), and some
asteroids and comets, but much more exploration
remains. As for the other planets and moons in our
solar system, a modest amount of progress has been
made, and a very large amount of exploration remains.
for nearby solar systems, advances in confirming
large planets has been made, but further exploration
via space telescopes currently planned will, perhaps
in the next 10 years, allow us to confirm whether or
not earthlike planets exist and if any of them have
signs of life as discernable via their chemical signa-
ture. Said exploration is currently planned for solar
systems within 100 light years of earth:
They May Know We're Here
article describing the way in which advanced
civilizations can detect life on distant planets, a method
which humans will begin to use to search for life up to
100 light years away, over ten years from now (now
being 2002, when the article was written).