ASTROBIOLOGY - Extraterrestrial Life Forms
" Is Life a random accident, or is the Universe in some way designed to produce it? 
In an infinite Universe...everything that can happen will happen, 
an infinite number of times"     
   ... Authur C. Clarke

Throughout human history man has wondered about the stars 
and possibility of extra-terrestrial life.
"Beyond the known World"

Man has always striven to expand his known territory.  
In our current age, we have begun a serious 
earch for Extra-Terrestrial Intelligence.

The discovery of extraterrestrial life would have significant 
biological and philosophical implications










Our world view is very ANTHROPOMORPHIC         

Our science and religions are based on a Humans only beliefs

The Question:  Is our world (LIFE) unique or 
is there animal life elsewhere in the Universe?


How Many ? of you believe that life exists elsewhere in the galaxy?






RARE EARTH Hypothesis  vs   DRAKE EQUATION... 
    is supposition that procaryotic-like organisms are common in planetary
    systems of the universe, but
animal life (INTELLIGENT) is very rare...  based upon:

1.  bacteria evolved on Earth as soon as environment allowed it,
                     and they inhabit extremely hostile terrestrial environs,
                     not unlike what might be found in other planetary systems
            2.  larger, complex (
animal) life occurred late in Earth history
Cambrian Explosion) under restricted environmental conditions
                      and higher life required a unique set of circumstances that
MAY NOT be common in other planetary systems

         Single celled procaryotic extremeophiles may exist everywhere, but a transition
                to multicelluar animals can occur only on a small fraction of planets, & only a
                few of those might lead to extraterrestrial intelligence.  EX: the dinosaurs
                survived for 150 m.y., yet without their chance extinction human life might 
                not have evolved.










         The Rare Earth supposition conforms to the Scientific Method 
                         in that it is
a TESTABLE hypothesis 

                            a) use telescopes (
Hubble) to find planetary systems
                            b) we can search for procaryotes (
Mars missions)
                            c) we can search for
SETI via radio-telemetry
                            d) we can send probes (satellites -









   Likely Ways (3) in which we might Discover Extra-Terrestrial Life.

1)  IN METEORITES  (& rocks from MARS ?) 
Murchison Meteorite - (Australia in 1969) - 1st real attempt...
                   contained many amino acids & things that look-like fossilized single cells.
       Moon Rocks
- a 2nd real attempt at search for extra-terrestrial life...    nothing.
      1976 VIKING Probes to Mars - were next attempts - mostly unsuccessful/inconclusive.
      1997 - McKay Group of NASA & ALH 84001 meteorite  
                                                                holds polycyclic aromatic hydrocarbons...









    Radiotelescope eavesdropping
SETI - Search for Extraterrestrial Intelligence 
    Arecibo - largest radio dish (Puerto Rico) - effective to 4,000 light years 
              False alarms - 1967 - Jocelyn Bell, Ph.D. candidate at Cambridge, 
                       detected regularly pulsating radio signal (called LGM - little green men
                       that was finally identified as rotating neutron stars
              Distances/probabilities of success are slim to none 
                       nearest star 4 light years away
                       our measurable universe is about 100,000 light years wide 
                               and it would take a radio signal 100 years to go that far
- (1895) - so we've been broadcasting for 100 years 
                                                                  imagine - our first message is
"I Love Lucy"

     Milky Way - 400 billion stars 
                       impossible to listen to all with radio-telescope or 
                       look at each with Hubble Space telescope






   Nov. 16, 1974 - Arecibo sends signal at 2.38 GHz at 3 trillion watts
(strongest man made signal ever), which was aimed at M13 star cluster some 25,000 lya.

     Other Earth signals might include...
Pioneer 10 (Mar 2, 1972 satellite) 1st man made object to leave solar system 
                                   will reach another star system in about 1,000 years

             maybe a better idea... why not an alien artifact - ala 2001: A space Odyssey  
                    could be.... set to signal us when we reach certain technological level... 
                    could be...  interrogate-able directly, like an interactive computer

             a received SETI signal might be a detailed genetic code allowing reconstruction 
                    of an alien being, here on Earth... idea 1st stated by Astronomer Fred Hoyle 

in 1960's BBS sci/fi series A is for Andromedia & in recent movie SPECIES 

to date - no non-random signals  we've scanned out to 40,000 ly  lack of signal to date










  3) DIRECT CONTACT VIA ALIENS &/or UFO's ........... well why not  ?



     Reasons we've Never Seen an ET







DRAKE EQUATION and Radio Astronomy

The current astrobiology paradigm is the view that alien civilizations do in fact exist and are 
numerous enough likely to be scattered among all the stars, but isolated from one another 
by the emptiness of interstellar space. Just for Earth's own galaxy, the Milky Way, 
experts have estimated that there might be up to one million advanced societies. 
The notion that alien civilizations are ubiquitous arose about forty years ago. 

The possibility of searching for ET's by radio astronomy was proposed by Giuseppe Cocconi 
and Philip Morrison in journal Nature in 1959. First project was called OZMA, when 

Dr. Frank D. Drake, then a young astronomer at a federal radio observatory in West Virginia, 
in 1959 was the fi
rst to scan the skies for faint alien signals, from 2 nearby stars.  He was 
quickly joined by like-minded experts, including Cornell astronomer Dr. Carl Sagan
Dr. Drake laid out his ideas in 1961, in what came to be known as the Drake Equation
The equation made educated guesses for the rate at which stars form, the fraction of stars 
with planets, the number of those planets on which life arises and so on, including the average 
lifetime of technological civilizations. By his equation Drake estimated that the Milky Way had 
about 10,000 civilizations capable of interstellar communication.

Later, Carl Sagan revised the calculations and raised the estimate to a million alien worlds. 
Since the cosmos holds hundreds of millions of galaxies, by that analysis the total number 
of alien societies could be astronomical.  One estimate put the number at roughly 10 trillion
alien intelligent societies. 









    given that : the Milky Way has 400 billions of stars -
         many stars may have planetary systems like our own...   none discovered yet

     given that : Cosmology believes that the portion of the Universe we can see and measure 
         is a typical (represntative sample) of ALL the UNIVERSE 
and an infinite abundance of matter is present in an infinitely vast universe...

     given that : same physcial laws that lead to formation of life on Earth 
         are present EVERYWHERE,

THEN :    LIFE & CONSCIOUSNESS should emerge elsewhere 
                                       as they have here ?????















    Some WILD GUESSES:       Drake Equation






           THUS  Aliens  and Man may look alike for they evolved under same physical laws








   So what will the ET's look like ?????
  - A sentient alien might have... 
         a spherical brain encased in a protective shell located above the ground 
         with sense organs situated near brain to reduce need for long information channels 
         with limbs for locomotion 
                   limbs... even in number for balance/stability 
                                  few in number for efficiency 
         with biochemistry similar to us......based upon DNA/RNA/proteins 

   - Likely to be an older civilization
       human civilization is ONLY but 10,000 years old... 
       if Big Bang is correct, then galaxies further out (?) may be much older. 
           a billion year old civilization might be so advanced to seem even Godlike = (Q) 
             we would then observe that man is not unique to God's universe, 
                    and that God also deals with other, more advanced civilizations... 
         or that we're technologically primitive.... the natural evolution of
                    technology may lead to abandonment of technology
             (built-in destruction via weaponry)







    Likely to be non-human, i.e., some sort of "BORG"
      artificial intelligence is very likely to appear & quite soon 
              Big Blue - May 12, 1997 beats the World's Chess Champion 
                           machines translate text, play chess, neural nets = microchips implants
                             a SETI signal is likely to be machine based. 
           some evolutionists believe biological intelligence is in transitory phase...
              a conscious, intelligent machine could have human intellect  (STARTREK) 

         distinctions between 
         organism/machine...................... are becoming blurred 
     machines with infinite size brains (cpu's) could build/repair/replace themselves
               and become immortal  -  T3








Some Religious Reasons:
   a beneficient God would desire to endow other worlds with life
    God would not have made so many stars just for the purpose of MAN alone
    An infinite God could scarcely find the opportunities to enjoy himself, 
                to exercise his Godhead, if a single planet were the sole seat of His activities

Some Contemporary Human Beliefs:
  1877, Giovanni Schiaparelli, describes Martian Canals... 
                Lowell Observatory (AZ) founded to view engineering society that made the canals
    1898, H.G.Wells - War of the Worlds - Martians invade Earth 1930's 
                Orson Wells broadcast on Halloween is believed by Eastern seaboard
    WWII - Warner von Braun - missles and rockets = ability to leave Earth 1940's
                popularity of UFO's rises... (UFO's are common throughout history of mankind)
    1950's to present --> Superman to Star Wars and Star Trek popularity
    1953, Miller/Urey (Chicago) - Origin of Life Experiments... aa's to life route is possible

for further information I recommend the book... Are We Alone?  Philosophical Implications of the Discovery of Extraterrestrial Life. by Paul Davies, professor of Natural Philosophy at University of Adelaide, Basic Books, Orion Productions, Harper Collins Publishers, Inc., 1995

back     last update - 14 May 2003









Charly Mallery, 
Department of Biology, 
University of Miami, 
Coral Gables, FL 33124-4621
14 May 2003





     If we were to discover extraterrestrial sentient life
       it would be THE greatest scientific revelation in the history of man.

    a consequence... if we believe that ET's do exist, wouldn't it be best for the human
                               species to be politically unified and speak with a single united voice. 











The Cambrian Explosion...               tbl 5.1 pg 467
    a period of geological time [from roughly 543 mya to 490 mya
         marking the emergence of (sea) ANIMAL life
                  see great diversity of fossilized animals absent in late Precambrian
an adaptive radiation due to (?) unique circumstances (?)        
                  most extraordinary biological event on our planet

    by 505 mya...  
majority of all animal phyla (between 28-40) had appeared
                                all basic animal body plans had been established

Possible causes of rapid evolution of animal life in Cambrian Explosion...
   1.  O2 levels reached some critical value - favored oxidative metabolism
                     favored biochemical evolution allowing making of hard skeletons
   2.  large amounts of nutrients became available
                     phosphorites, nitrates, & Fe  (via deep sea upswellings)
   3.  temperatures become moderate
   4.  continental drift (which lasted 10-15 my) was occurring at this time 








Extremophiles (bacteria that live in very hostile environments)

        the origin of microbial life elsewhere in the Universe (extremophiles)
        DOES NOT mean that Natural Selection will inevitably lead it onto
        intelligent animal life.

        While bacteria have been on Earth since the beginning, animal life
        only appeared recently (500 million years ago).










  The Widely Held View is that ET's do Exist.

        FERMI PARADOX:  in 1950 Enrico Fermi, a prominent nuclear physicist, quips...
            if ET's are common place, "WHERE ARE THEY ?"  Shouldn't their presence
            be obvious?

    5 Reasons we have never seen an ET...

        1.   inter-stellar travel is NOT feasible
                    ans:  no principle of physics say interstellar travel is not feasible
                                even at 20% of the speed of light, we could get to nearby
                                stars in a decade

        2.  ET's are searching for us, but are not here yet...
                    ans:  an civilization with rocket technology should be able to cross
                                the galaxy eventually (in the 12 billion year history of the
                                universe someone should have been here by now)




     3.  ET's don't like to travel to far from home...
                    ans:  human nature has always been one of expansion and colonization.
                           colonization grows exponentially  (see article)
                                    the time limits to colonizing the Universe are the
                                    speed of rocketry and the rate of establishing the new colony.

                            Let use a trip rate of 100 years and 400 years to establish a colony

                            The universe if about 100,000 light years across...
                                humans could leap frog (planet to planet) across the known Universe
                                in 3.75 to 5.0 million years, a mere "second" in a 12 billion year old
                                Universe.  Humans took 5,000 years to go from caveman to space
                                flight, thus the upper limits of colonization might be only
                                50 million years








        4.  ET's are here, but don't like us (or have a 'Prime Directive')
                    have a policy of non-interference,  or they came & left

        5.  We are ALONE and are the most advanced life-form in the galaxy