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Life Facts

Steven Parry

Introduction Charles Darwin in 1859 proposed that life may have brewed in a soup of organic chemicals in some “warm little pond� on the surface of the primordial Ear th. He left the question open - it remains open. His inheritors have proposed that life could have been generated in the first sunlit oceans that swept across the young planet, or in the crater left by an asteroid impact, or made a template of itself in a bed of wet clay, or that maybe it had been delivered in a meteoritic fragment from a faraway planet. As far as we know life exists on Ear th, nowhere else. This book is divided into two sections. Facts explores the facts for life and Theory explores the theories for extraterrestrial life.

Contents Section 1 - Facts Introduction 1. Building Blocks For Life 2. Ingredients For Life 3. Life In Unexpected Places 4. Friends For Life Section 2 - Theory Introduction by Stephen Hawking 1. The Drake Equation 2. The Fermi Paradox 3. ExtraTerrestrial Solar System 4. Extra Solar Planets 5. Life But Not As We Know It The Blue Room - Pullout

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1- Building Blocks For Life

There are more than 92 natural elements found on Ear th, almost all life forms on Ear th are primarily made up of only four basic elements: hydrogen, oxygen, nitrogen, and carbon. These elements are four of the most common chemically active elements in the Universe.

Life Facts

Nitrogen

4

Carbon

Nitrogen is essential for life because nitrogen-based compounds make up DNA or deoxyribonucleic acid, which is the blueprint for all life on Ear th. DNA facilitates building all of the other larger structures necessary for life to function and replicate.

Amino Acids

Life is made of organic compounds, which contain the element carbon. Carbon plays a key role in life, because it links together other elements to form large and complex molecules.

Proteins

Amino acids are a group of twenty carbon-based compounds that have a carboxyl group and an amino group (nitrogen containing) bonded to the same carbon atom. They are impor tant for life because they serve as the building blocks of protein molecules that make up living organisms. Proteins are extremely diverse and essential for life as they are the building blocks for cell construction, maintenance, and reproduction in living organisms. Structural components of life such as cell membranes, muscles, and tissues are all made from proteins.


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Building Blocks For Life


Life Facts

2 - Ingredients For Life

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Water Any life which is based on molecules almost cer tainly requires some kind of liquid solvent to be able to move them around. Although chemical reactions can take place in gases and solids these are much less ideal than liquid. Gas phase reactions happen only with molecules that are volatile enough to be present in large quantities in a gas. Reactions can take place in solids, but occur very slowly. Both of these limitations make it much more likely for life to develop in liquid, as indeed it seems to have on Ear th.

Water is also the second most common molecule in the universe (after H2). Other liquids exist naturally in the universe, but not in the sor t of abundance water does. Most of these liquids don’t have many of the other key proper ties of water that make it so suitable as the basis for life. Any life which is based on molecules almost cer tainly requires some kind of liquid solvent to be able to move them around.

Ingredients For Life

Water has many unique physical and chemical proper ties that make it well suited to suppor t the complex chemistry required for life. Expanding when it freezes keeps oceans and lakes on Ear th from freezing solid. Water can dissolve many substances easily and it also has a high heat capacity, which means it takes a lot of energy to cause water to change temperature. This proper ty of water gives Ear th its relatively moderate climate.

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Life Facts

Habitable Zone

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The habitable zone is the scientific term for the region around a star within which it is theoretically possible for a planet with sufficient atmospheric pressure to maintain liquid water on its surface. Since liquid water is essential for all known forms of life, planets in this zone are considered the most promising sites to host extraterrestrial life.


Galactic Habitable Zone

The Habitable Zone is sometimes referred to as The Goldilocks zone. The name originates from the story of Goldilocks and the Three Bears, in which a little girl chooses from sets of three items, ignoring the ones that are too extreme (large or small, hot or cold, etc.), and settling on the one in the middle, which is “just right”. Likewise, a planet following this Goldilocks Principle is one neither too close nor too far from a star to rule out liquid water on its surface.

Ingredients For Life

Goldilocks Zone

“Habitable zone” is sometimes used more generally to denote various regions that are considered favorable to life in some way. One example is the Galactic Habitable Zone, (representing the distance of a planet from the galactic centre), based on the position of the Ear th in the Milky Way. If different kinds of habitable zones are considered, their intersection is the region considered most likely to contain life. The location of planets (and moons) within its parent star’s habitable zone is but one of many criteria for planetary habitability but it is theoretically possible for habitable planets to exist outside the habitable zone.

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Life Facts


Habitable zones, however, are not stable. Over the life of a star, the nature of the zone moves and changes. Our Sun is the type of star know and a yellow dwarf, yellow dwarfs expand as they consume their Hydrogen ‘fuel’. Our sun will expand, get hotter and brighter by about 10% each billion years. The habitable zone will gradually move away from the Ear th and it will become too hot here to maintain liquid water. However the habitable zone will be in the orbit of Mars and eventually even fur ther out into the solar system.

Ingredients For Life

Zone Future

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Lucky Star Any life forms will need to use some of the elements heavier than helium (carbon, nitrogen, oxygen, phosphorus, sulphur, chromium, iron, and nickel, for example) for biochemical reactions. This means that the gas cloud which forms the star and its planets will have to be enriched with these heavy elements from previous generations of stars. If the star has a heavy element/metal-rich spectrum, then any planets forming around it will be enriched as well. The life-span of a star is also impor tant for life.

Star Groups Stars are grouped into three categories population1, 1I and 111 based on their heavy elements. The Sun belongs to the Population I group of stars, which contain relatively large amounts of heavier elements. The first ever stars made from pure hydrogen and helium are Population III. These exploded as supernovae, fusing the lighter elements into heavier and heavier elements. Our Sun, then, contains the metal from previous generations of stars that went supernova.

Life Facts

Life Span

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The lifespan of a star can range from a few million years to trillions of years depending on its type and size. The larger stars consume their fuel much more quickly than their smaller counterpar ts and therefore ‘burn out’ at a faster rate. The sun is a yellow dwarf (Type G) and has a life span of approximately 9 billion years. It is currently middle aged at around 4.5 billion years old. These types of stars fall into a stable period of activity lasting billions of years. These stable conditions allow time for complex life to evolve.


Larger stars are much hotter than the sun and the largest live for just a few millions of years before going supernova. They tend to give out huge and violent radioactive flares on a much larger scale than the solar flare witnessed on the Sun. These conditions make it unlikely for life to get a foothold and evolve. The type and category of star the sun is makes it ideal for the evolution of life, as we know it.

Ingredients For Life

Large Stars

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3 - Life In Unexpected Places

Life Facts

In recent years evidence has been discovered of life thriving in places once thought impossible. These discoveries have opened up the possibility of life evolving in places in the solar system once unthought. of Life, traditionally seen as being driven by energy from the sun, has been discovered in places where sunlight cannot and doesnot reach.

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Hydrothermal Vents

Vent Communities

Black smokers were first discovered in 1977 and are typically found in the abyssal and hadal zones. They appear as black chimney-like structures that emit a cloud of black material. Black smokers are formed in fields hundreds of meters wide when superheated water from below Ear th’s crust comes through the ocean floor. This water is rich in dissolved minerals from the crust, most notably sulphides. When it comes in contact with cold ocean water, many minerals precipitate, forming a black chimney-like structure around each vent. Relative to the majority of the deep sea, the areas around submarine hydrothermal vents are biologically more productive, often hosting complex communities fuelled by the chemicals dissolved in the vent fluids, suppor ting diverse organisms, including giant tube worms, clams, limpets and shrimp. Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food. The water that comes out of the hydrothermal vent is rich in dissolved minerals and suppor ts a large population of chemoautotrophic bacteria.

Life In Unexpected Places

Black Smokers

A hydrothermal vent is a fissure in a planet’s surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apar t, ocean basins, and hot spots Under the sea, hydrothermal vents may form features called black smokers.

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In recent years organisms have been discovered thriving in environments toxic to us but essential to them.

Life Facts

Snottites

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Snottites are colonies of single-celled extremophilic bacteria which hang from the walls and ceilings of caves and are similar to small stalactites, but have the consistency of “snot�, a slang word for nasal mucus. The bacteria derive their energy from chemosynthesis of volcanic sulphur compounds including H2S and warm-water solution dripping down from above, producing sulphuric acid. Because of this, their waste products are highly acidic with similar proper ties to battery acid.


Also found in this extreme environment are phlegm balls. They are vibrant microbial communities; grey wads of material with the consistency of cooked cabbage, not clinging to life in a narrow niche but thriving. According to researcher Penny Boston “We have discovered”—she means scientists in general— ”organisms thriving in environments harsh to us but essential to them. It broadens your perspective. We all suffer to some extent from ‘exper titis’ in science. It’s good for your soul, and good for your intellect, and good for your work to have your imagination stretched, to be open to the possibilities.”

Life In Unexpected Places

Phlegm Balls

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4 - Friends For Life Jupiter Jupiter is our solar system’s largest planet. Jupiter’s powerful gravity prevented space rocks orbiting near it from coalescing into a planet, and that’s why our solar system has an asteroid belt.

Life Facts

Jupiter’s gravity also protects us from comets. Long-period comets enter the solar system from its outer reaches. Jupiter’s gravity slings most of these fast-moving ice balls out of the solar system before they can get close to Ear th. So long-period comets are thought to strike Ear th only about every 30 million years. Without Jupiter nearby, longperiod comets would collide with our planet up to 1000 times more frequently.

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Without this protection it is very unlikely the Ear th would have had the stable periods needed for life.


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Friends For Life


1- Building Blocks For Life Moon The moon is an impor tant factor for the evolution of life on Ear th. Without the moon the stable conditions for complex life evolution would not more exist. than 92 natural elements found on Ear th, almost all There are life forms on Ear th are primarily made up of only four basic elements: hydrogen, oxygen, nitrogen, and carbon. These elements are four of the most common chemically active elements in the Universe.

Nitrogen

Carbon

Amino Acids

Nitrogen is essential for life because nitrogen-based compounds make up DNA or deoxyribonucleic acid, which is the blueprint for all life on Ear th. DNA facilitates building all of the other larger structures necessary for life to function and replicate. Life is made of organic compounds, which contain the element carbon. Carbon plays a key role in life, because it links together other elements to form large and complex molecules. Amino acids are a group of twenty carbon-based compounds that have a carboxyl group and an amino group (nitrogen containing) bonded to the same carbon atom. They are impor tant for life because they serve as the building blocks of protein molecules that make up living organisms.

LifeLF ife acts Facts

Proteins

3

20

Proteins are extremely diverse and essential for life as they are the building blocks for cell construction, maintenance, and reproduction in living organisms. Structural components of life such as cell membranes, muscles, and tissues are all made from proteins.


Stabilizer

Oceans

The Moon has influenced biology in other ways as well. For species living near the coast, the tide is an impor tant factor. When you look at the shorelines, you can recognize different layers of organisms that have adapted to the salt water conditions based on the ebb and flow of the tide. If you would take away the Moon suddenly, it would change the global altitude of the ocean. Right now there is a distor tion which is elongated around the equator, so if we didn’t have this effect, suddenly a lot of water would be redistributed toward the polar regions.

Friends For Life

Biology

The Moon has been a stabilizing factor for the axis of rotation of the Ear th. If you look at Mars, for instance, that planet has wobbled quite dramatically on its axis over time due to the gravitational influence of all the other planets in the solar system. Because of this obliquity change, the ice that is now at the poles on Mars would sometimes drift to the equator. But the Ear th’s moon has helped stabilize our planet so that its axis of rotation stays in the same direction. For this reason, we had much less climatic change than if the Ear th had been alone. And this has changed the way life evolved on Ear th, allowing for the emergence of more complex multi-cellular organisms compared to a planet where drastic climatic change would allow only small, robust organisms to survive.

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Charles Darwin in 1859 proposed that life may have brewed in a soup of organic chemicals in some “warm little pond� on the surface of the primordial Ear th. He left the question open: it remains open. His inheritors have proposed that life could have been generated in the first sunlit oceans that swept across the young planet, or in the crater left by an asteroid impact, or made a template of itself in a bed of wet clay, or in the dark silence of submarine volcanoes, or that it had been delivered in a meteoritic fragment from a faraway planet. As far as we know life exists on Ear th, nowhere else. This book is divided into two sections. Facts explores the facts for life and Theory explores the theories arising from the facts.

Contents Section 1 - Facts Introduction 1. Building Blocks For Life 2. Ingredients For Life 3. Life In Unexpected Places 4. Friends For Life

2 3 5 13 17

LIFE THEORY

Section 2 - Theory Introduction 1. The Drake Equation 2. The Fermi Paradox 3. Extra Terrestrial Solar System 4. Extra Solar Planets 5. Life But Not As We Know It The Blue Room - Pullout

23 24 28 30 34 36


“If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didnot turn out very well for the American Indians.� STEPHEN HAWKING


ABSENCE OF EVIDENCE IS NOT

EVIDENCE

OF ABSENCE


Life Theory

“Wherever I go in the world people ask me ‘do aliens exist?’ Its a good question because it cuts to the hear t of how we see our place in the universe. Are we alone on our small round blue ball? I think probably not because of one fact; the universe is big, really big! Our planet is just one of eight orbiting around our sun, which itself is hardly special being one of about two hundred billion stars in a vast spiral. Our galaxy the Milky Way, so big sometimes I find it hard to comprehend. But even the Milky Way is a tiny drop in the cosmic ocean, just one of one hundred billion galaxies formed into an enormous web stretching away in all directions. This puts our tiny world in perspective but also makes it difficult to believe we really are alone”

Stephen Hawking


1 - The Drake Equation

The Drake Equation is a mathematical equation used to estimate the number of detectable extraterrestrial civilizations in the Milky Way galaxy. It is used in the field of the Search for ExtraTerrestrial Intelligence (SETI). The equation was devised in 1961 by Frank Drake while at the National Astronomy and Lonosphere Center.

Life Theory

Great Filter

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The Drake Equation is closely related to the Fermi Paradox in that Drake suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations (the Fermi Paradox) suggests that technological civilizations tend to disappear rather quickly. This leads to the Great Filter, which notes that since there are no observed extraterrestrial civilizations, despite the vast number of stars, then some step in the process must be acting as a filter to reduce the final value. According to this view, either it is very hard for intelligent life to arise, or the lifetime of such civilizations must be relatively shor t.


N=

the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone)

R* =

the average rate of star formation per year in our galaxy

fp =

the fraction of those stars that have planets

ne =

the average number of planets that can potentially suppor t life per star that has planets

fl =

the fraction of the above that actually go on to develop life at some point

fi =

the fraction of the above that actually go on to develop intelligent life

fi =

the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L=

the length of time for which such civilizations release detectable signals into space

The Drake Equation

The Drake Equation States That:

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The number of stars in our galaxy is 200,000,000000, the number of galaxies in the universe is estimated at around 100,000,000000. There are more stars in the universe than there are grains of sand on every beach on planet Ear th.

Drakes Calculation For The Milky way Frank Drake’s own current solution to the Drake Equation estimates10,000 communicative civilizations in the Milky Way.

Life Theory

2 30

, 0 0

0 0 0

0 0 ,

, 0

0 0

S 0

rs a t

0 1


0 0

civili

The Drake Equation

0 , 0

ations z

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2 - The Fermi Paradox The Fermi Paradox (or Fermi’s Paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity’s lack of contact with, or evidence for such civilizations. The theory was raised by physicists Enrico Fermi and Michael H. Har t.

Main Points 1 - The Sun is a young star. There are billions of stars in the galaxy that are billions of years older ; 2 - Some of these stars likely have Ear th-like planets which, if the Ear th is typical, may develop intelligent life; 3 - Presumably some of these civilizations will develop interstellar travel, as Ear th seems likely to do; 4 - At any practical pace of interstellar travel, the galaxy can be completely colonized in just a few tens of millions of years.

Life Theory

Arguments

32

According to this line of thinking, the Ear th should have already been colonized, or at least visited. But no convincing evidence of this exists. Fur thermore, no confirmed signs of intelligence elsewhere have been spotted, either in our galaxy or the more than 80 billion other galaxies of the observable universe. Hence Fermi’s question “Where is everybody?”. Cer tain theoreticians accept that the apparent absence of evidence implies the absence of extraterrestrials and attempt to explain why. Others offer possible frameworks in which the silence may be explained without ruling out the possibility of such life, including assumptions about extraterrestrial behaviour and technology. Each of these hypothesized explanations is essentially an argument for decreasing the value of one or more of the terms in the Drake Equation. Some of the key arguments in this theory are as follows:


No other civilizations have arisen It is the nature of intelligent life to destroy itself It is the nature of intelligent life to destroy others Life is periodically destroyed by naturally occurring events Human beings were created alone They do exist, but we see no evidence

Communication is improbable due to problems of scale

Intelligent civilizations are too far apart in space or time It is too expensive to spread physically throughout the galaxy Human beings have not been searching long enough Humans are not listening properly

They are non-technological The evidence is being suppressed They choose not to interact with us They are here unobserved

The Fermi Paradox

Civilizations broadcast detectable radio signals only for a brief period of time

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3 - ExtraTerrestrial Solar System

Life Theory

After the discovery of organisms in such exotic and sometimes toxic environments on Ear th scientists were inspired to look anew at the rest of the solar system as potentially habitable. They also discovered signs that life appeared early in the Ear th’s history. Intriguingly, at about the time life arose on Ear th, Mars was a much more hospitable planet than it is today. Images of the Mar tian surface indicate that the planet once had flowing rivers and perhaps an ocean. Life could even have star ted on Mars and spread to Ear th aboard a meteorite.

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Panspermia

The idea that organics — or even organisms — drift from world to world like spores on the wind is an unfamiliar one for most people. But unfamiliar ideas have a way of becoming familiar, and even commonplace, quickly. The great, thriving terrarium that is Ear th may be unique in our solar system. But if the new findings show anything, it’s that our planet may not be at all unique — or even terribly special — in the cosmos as a whole.

Extra Terrestrial Solar System

Panspermia — the theory that life on Ear th may have come from beyond, if not bacteria from Mars, then organic raw materials from comets or asteroids that rained down on the planet back in the heavy bombardment days of the early solar system. It’s an idea that’s spawned a lot of faculty-lounge theorizing for more than a century, but in recent years, it’s attained a new credibility. Observations from both space-based and Ear thbound telescopes as well as interplanetary probes have shown that organic chemistry is common everywhere in the cosmos. Space is rich in hydrocarbons, water and even the amino acids essential to life. Nucleobases, amino acids and sugars have been found in meteors that have crashed to Ear th. Our planet’s water is thought by many scientists to have been impor ted by ice-heavy comets long ago, preparing the planet for the life it would one day suppor t.

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E uropa Jupiter’s moon Europa is a frozen ball of ice, but due to the proximity to its parent planet and orbit the pull of gravity is thought to heat up the inside of the moon melting the centre producing an ocean of liquid water.

Deep Ocean

Life Theory

Lakes

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In the 1990s, NASA’s Galileo probe found strong evidence of a deep, briny ocean covering the entire moon far beneath the icy surface. The discovery of the moon-girdling ocean immediately prompted speculation that such an environment could foster life. But to do so, scientists said, organic compounds from Europa’s surface would need to find their way through the ice. Subsurface lakes and the process that creates them would provide just such channels. Huge piles of jumbled-up icebergs strewn across the cracked and mottled surface of Europa has led to a new theory that explains these vast “chaos terrains” as the tips of subsurface lakes that well up and warm the surface. The existence of such lakes would thrill scientists seeking life beyond Ear th, a group long drawn to Europa. “Europa has the best chance of having life there today,” said Britney Schmidt, who studies the moon at the University of Texas at Austin and led the new study appearing in the journal Nature. Such lakes could provide a habitat for life or act as channels for organic compounds on Europa’s surface to be drawn into the moon’s far deeper ocean, said Don Blankenship, a geophysicist and Europa specialist also at the University of Texas.


Exotic Life

Extra Terrestrial Solar System

The surface of Europa is too cold for any liquid water. But as warm water seeps up, heated from the planet’s mantle below, it would break the surface ice into a jumble of miles-long icebergs. The icebergs then flip, float and freeze in place. “It’s a vigorous process,” Schmidt said. “Material is getting thrown around. Icebergs are flipping over. Brines are going up and coming back down.” Schmidt arrived at the theory after she traveled to Antarctica, which hosts a hundred or more subsurface lakes. One, Lake Vostok, holds intrigue as a possible home for exotic life on Ear th.

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4 - Extra Solar Planets

An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of 853 such planets (in 672 planetary systems, including 126 multiple planetary systems) have been identified as of December 1, 2012, all of them within the Milky Way galaxy. It is expected that there are many billions of planets in the Milky Way galaxy not only occurring around stars but also as free-floating planetary-mass bodies. The nearest known exoplanet is Alpha Centauri Bb.

Life Theory

Habitable Zone

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The discovery of extrasolar planets, par ticularly those that orbit in the habitable zone where it is possible for liquid water to exist on the surface (and therefore also life), has intensified interest in the search for extraterrestrial life. Thus, the search for extrasolar planets also includes the study of planetary habitability, which considers a wide range of factors in determining an extrasolar planet’s suitability for hosting life.


Giants

Extra Solar Planets

Most known exoplanets are giant planets believed to resemble Jupiter or Neptune, but this reflects a sampling bias, as massive planets are more easily observed. Some relatively lightweight exoplanets, only a few times more massive than Ear th (now known by the term Super-Ear th), are known as well; statistical studies now indicate that they actually outnumber giant planets while recent discoveries have included Ear thsized and smaller planets and a handful that appear to exhibit other Ear th-like proper ties.There also exists planetary-mass objects that orbit brown dwarfs and other bodies that “float free” in space not bound to any star ; however, the term “planet” is not always applied to these objects.

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5 - Life - But Not As We Know It Professor Stephen Hawking outlined three possibilities with regards to alien life: One, that there is no life out there; and two, somewhat pessimistically, that when intelligent life gets smar t enough to send signals into space, it is also busying itself with stockpiling nuclear bombs and three “Primitive life is very common and intelligent life is fairly rare,” “Alien life may not have DNA like ours. Alien life may not even depend on the things that we think neccessary for life.”

Water ?

Life Theory

Carbon ?

40

Frstly is water necessary for life? Not necessarily, according to Professor Hawking, Ammonia, for example, has many of the same proper ties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based “habitability zone”. One example of such a location would be right here in our own solar system on Saturn’s largest moon Titan. Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically suppor t alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of suppor ting life in some extreme planetary conditions. What we normally think of as ‘life’ is based on chains of carbon atoms, with a few other atoms, such as nitrogen or phosphorous, Hawking observed in his lecture, Life in the Universe. We can imagine that one might have life with some other chemical basis, such as silicon, “but carbon seems the most favorable case, because it has the richest chemistry.”


The Ear th was formed largely out of the heavier elements, including carbon and oxygen. Somehow, Hawking observes, “some of these atoms came to be arranged in the form of molecules of DNA. One possibility is that the formation of something like DNA, which could reproduce itself, is extremely unlikely. However, in a universe with a very large, or infinite, number of stars, one would expect it to occur in a few stellar systems, but they would be very widely separated.”

Phosphorus

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Ear th, we speculate that the same must be true throughout the Universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of suppor ting life under the right conditions. Even on Ear th some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

Life - But Not As We Know It

Arsenic

Other prominent scientists have warned that we humans may be blinded by our familiarity with carbon and Ear th-like conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Ear th, one species’ “sweet spot” is another species’ worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based fete.

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What could ET look like? Finally, looking at the facts and theories has enabled scientists to make an intelligent guess as to what form an alien life form may take. Taking into account potential chemical make up, atmospheric conditions and gravity has enabled some intriguing ideas. The following pictures are from the television series ‘Stephen Hawkings Universe’.

Europa: Sea Life

Life Theory

A squid-like creature feeds on the bottom of the salty ocean thought to exist below the icy crust of this moon of Jupiter. Europa is the only large body, other than Ear th, that may have large volumes of water capable of suppor ting life. If organisms exist in this perpetually dark sea, they may exhib it characteristics of deep sea creatures in Ear th’s oceans, including bioluminescence and a nutrient chain based around hydrothermal vents.

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Low Temperature Another extreme where life may be possible are worlds where the average temperatures are down to the levels of liquid nitrogen (less than minus 300 degrees Fahrenheit). Such extremes would require organic components and physiologies radically different than those found on terrestrial planets largely dependent on liquid water. In theory if energy is available in some form that can sustain biological activity even at such low temperatures life may be possible.

With gas giants like Jupiter such a common type of planet, many scientists and fiction writers have wondered if life could evolve and survive in such dense, violent atmospheres. This imaginary skyscape shows what one of these gas creatures may look like even though a plausible mechanism for the origin of life in such conditions is beyond the scope of current biochemical investigations.

Life - But Not As We Know It

Gas Creatures

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THE BLUE ROOM


A bizarre memo that appears to prove that aliens did land in New Mexico prior to 1950 has been published by the Federal Bureau of Investigation. The bureau has made thousands of files available in a new online resource called The Vault. Among them is a memo to the director from Guy Hottel, the special agent in charge of the Washington field office in 1950. THIS IS THAT MEMO


The Blue Room is supposedly the storage and research facility where alien artifacts are stored and reverseengineered It is located somewhere on the Wright-Patterson Air Force Base, and the blue room is also known as Hangar 18 and Building 18-F, 3rd Floor


“It is unnatural in a large field to have only one shaft of wheat, and in the infinite universe only one living world.” M etrodorus O f C hios

Steven Christopher Parry ©2012


Set in Gill Sans Light 10pt

Source Material: Joel Achenbach - National Geographic magazine, Stephen Hawking’s Universe, Stars and Planets, Extreme Universe Steven Parry Research: Steven Parry Editor: Design: Steven Parry Illustrations: Steven Parry except: Page 2 Hubble Deep Field Google Images Page 20 Earth Google Images NASA Page 34–35 Mars Landscape Page 42–43 Extraterrestrials Google Images


Life Facts & Theory