ASTRONOMY 112
EXTRA-TERRESTRIAL
DEBATE
PRO TEAM
Opening Statements
 Earth is estimated to be 4.5 billion years old
 Life is the condition that distinguishes organisms from
inorganic objects and dead organisms, being
manifested by growth through metabolism,
reproduction, and the power of adaptation to
environment through changes originating internally.
 The earliest proof of life on earth is 3.4 billion years oldfossilized mats of cyanobacteria called stromatolites
found in Australia, but many scientists believe life could
have began as early as 3.8 billion years ago
Do extraterrestrials exist?
 Habitable zones:
 Goldilocks zone- is the region around a star within which planetary-mass
objects with sufficient atmospheric pressure can support liquid water at
their surfaces
 G dwarfs- similar to our sun with little variance 0.8-1.2 solar masses
 M dwarfs- .075-roughly .5 solar masses (Smaller Goldilocks zone, but
possible)
 Within 33 light years, there are 240 known M dwarfs (Sun )that could
serve as suns for potentially habitable galaxies.
 The existence of water vapor is an indication that there is some sort of
atmosphere
 Significant “plumes of water vapor” were spotted recently by scientists via
the infrared space telescope that has been set up by the European Space
Agency (ESA) at the Herschel Space Observatory.
Do extraterrestrials exist?
 Habitable zones: Kepler Mission
All Exoplanet Counts

Kepler looks at over 100,000 stars for at least 3.5 years

Results

442 Systems with Multiple Planets
Discovery Method
Number of
Planets
Astrometry
1
Imaging
34
Radial Velocity
499
Transit
1126
Transit timing
variations
3
Eclipse timing
variations
7
Microlensing
24
Pulsar timing
variations
5
Pulsation timing
variations
1
Orbital brightness
modulations
3
All Exoplanets 1703
Transiting
Exoplanets
1136
Does ET exist?
National Geographic
 Over 1700 planets discovered to date orbiting 1033
stars
 16 possible to support life
 0.94% probability
 What is 1% of even 1% of all the stars in the universe?
Do extraterrestrials exist?
 Drakes equation/Fermi’s paradox:
 Within the limits of our existing technology, any practical search for
distant intelligent life must necessarily be a search for some
manifestation of a distant technology. After about 50 years, the
Drake equation is still of seminal importance because it is a 'road
map' of what we need to learn in order to solve this fundamental
existential question.
 Trans-Atlantic radio established 1927
 1936 Winter Olympics transmission- Hitler was the first to make a
radio transmission significant enough (Ironic)
 Less than 100 years of transmission compared to 3.4 billion years
of life on Earth
Do extraterrestrials exist?
Speed of Light
Theory:
 A coherent group of tested general propositions,
commonly regarded as correct, that can be used as
principles of explanation and prediction for a class of
phenomena
 A proposed explanation whose status is still conjectural
and subject to experimentation, in contrast to wellestablished propositions that are regarded as reporting
matters of actual fact
Do extraterrestrials exist?
Speed of Light
In their time “Commonly Regarded as Correct”
Theories
 “The World is flat.” -1492
 “Humans are not meant to fly.”-17 December
1903
 “Humans will never travel into space.”-12 April
1961
 Etc……
Astrobiology/Biology

Elements of chemical Composition:

The four most common elements in the universe are hydrogen, helium, oxygen, and
carbon. The four most common elements in the human body (and really, for most of life on
earth) are oxygen, carbon, hydrogen, and nitrogen. The fact that three of these overlap
demonstrates how life relies on common elements, not those that are rarer. Assuming that the
general ratio of elements in the universe holds true, it would make sense that there are other
life forms when a similar combination of elements are in the presence of energy.

The background radiation on Earth is due to the decay of earthly nuclear materials found in the Earth’s crust,
but is now be considered to be from debris of extra-terrestrial fission and fusion reactions taken place by the
sun of the stats in the cosmos.
-The Big Bang made Hydrogen,
Helium, and some trace amounts
of Lithium
-All other elements are made inside
of stars through fusion
Astrobiology/Biology
 10 November 2008 Scientists revealed that tiny
creatures called water bears (tardigrades) are the first
animals to survive exposure to space. Sending water
bears into space is one of several ESA experiments
looking at organisms which can survive longer periods
in open space.
 Tardigrades can withstand temperatures ranging from 272 deg C(-457 deg F) to +150 deg C(302 deg F), they
can be without water for a period of 10 years, and they
are extremely resistant to radiation.
 Life finds a way to survive whenever survival is
possible whether we can fathom it or not.
What does this mean for us

Elements of chemical Composition:

The four most common elements in the universe are hydrogen, helium, oxygen, and
carbon. The four most common elements in the human body (and really, for most of life on
earth) are oxygen, carbon, hydrogen, and nitrogen. The fact that three of these overlap
demonstrates how life relies on common elements, not those that are rarer. Assuming that the
general ratio of elements in the universe holds true, it would make sense that there are other
life forms when a similar combination of elements are in the presence of energy.

1976, The Viking Mars landers detect chemical signatures indicative of life. Tests performed on
Martian soil samples by NASA's Viking landers hinted at chemical evidence of life. One
experiment mixed soil with radioactive-carbon-labelled nutrients and then tested for the
production of radioactive methane gas. The test reported a positive result. The production of
radioactive methane suggested that something in the soil was metabolising the nutrients and
producing radioactive gas.

In, 2002, Chemical hints of life are found in old data from Venus probes and landers. Life in
Venus' clouds may be the best way to explain some curious anomalies in the composition of its
atmosphere, claimed by the University of Texas astrobiologists in 2002. Solar radiation and
lightning should be generating masses of carbon monoxide on Venus, yet it is rare, as though
something is removing it. Hydrogen sulphide and sulphur dioxide are both present too. These
readily react together, and are not usually found co-existing, unless some process constantly is
churning them out. Most mysterious is the presence of carbonyl sulphide. This is only produced
by microbes or catalysts on Earth, and not by any other known inorganic process. Venus's
conditions 50 kilometres up in the atmosphere are more hospitable and moist, with a
temperature of 70°C and a pressure similar to Earth.
Closing Arguments
Technology

Babbage & son (1833)

Intel introduced its first 4-bit microprocessor 4004 in 1971

First cellphone-1973

First smartphone sold in 1993

Iphone(4GB)-2007

Iphone(64GB)-2014
Space

Moon landing- 20 July 1969

Mars 2&3 probes- 1971

Sojourner- 4 July 1997 first successful Mars rover landing
What creates life?
 I cannot conclude that I should be so ignorant
as to think that humans are the only intelligent
beings in the vastness of our universe.
 I refuse to believe that life only “rolled the dice”
once and we are the best thing it came up with.