Possible Extra Terrestrial Life

Benjamin Hastings April 10, 2013 Did Someone Move in Down the Street? An Exploration of Possible Extraterrestrial Life in the Universe, Perhaps Our Own System Other life in the universe just makes sense. Think about it, there are trillions of other stars in existence in our universe, and most of those stars have satellites, and those satellites have satellites. There are literally hundreds of trillions, if not more, planets or planet-sized satellites orbiting stars. To think that none of these could have life on them is just to be naive.

If it happened to our planet, out of hundreds of trillions of them out there, it can happen to another, and another. We can’t be alone; distant, maybe, but alone is just too far-fetched a theory. Belief in extraterrestrial life dates back quite far, even back to ancient society. “Regarding the existence of other worlds, the ancients of both Greece and rome were deeply divided. Arguing affirmative were the Epicureans, so called after Epicurus (341-270 B. C. ), who developed certain ideas that had originated with Democritus and Leucippus two centuries earlier. Among the theories that we today consider most modern are… hat life exists elsewhere in the universe… Modern though these ideas may seem to us, they all indisputably date from antiquity… ” (Crowe- 3) We aren’t the first people to think that life must exist elsewhere, we’ve simply brought the thought back into popularity. But where could life be sustained? Bacteria have been observed to endure extreme conditions “in environments with very high or low temperature and where conditions are very acidic or very alkaline. ” (Fix) Principles such as this suggest that “the search for life in the solar system should not be confined to the most benign environments. (Fix) Research and discoveries by Dr. Gene D. McDonald in Siberian permafrost showed that “single-celled organisms such as bacteria, archaeans, and fungi repair cellular damage for tens of thousands of years – and perhaps many times longer—after being frozen solid. ” (Hart) This is incredible when considering the damage the organisms sustain while being frozen; “even when all life processes appear to have stopped, processes that affect life do not. Organisms frozen in soil continue to be bombarded by radiation from elements within the soil itself.

And at any temperature above absolute zero, all molecules vibrate a little. Thus, cells’ DNA and other important molecules continue to sustain life-threatening damage. For organisms to remain viable for long periods of time, they must somehow maintain a minimal level of molecular repair. ” (Hart) A breakthrough such as this suggests that if bacteria on Earth could survive temperatures this low, then certainly organisms outside of What we consider to be the inhabitable temperature zone could certainly adapt and survive on distant moons or dwarf planets.

Mars, the fourth and last Solar terran planet, could hold, or have held, life on its surface. Recent study of an ancient meteorite strengthens this theory. “The meteorite… is made of igneous rock that solidified about 4. 5 billion years ago at the time that Mars formed. About 3. 6 billion years ago globules of carbonate minerals were deposited in cracks in the rock. The carbonate minerals may have been deposited when liquid water seeped into the cracks. The impact of an asteroid or comet on Mars 16 million years ago ejected the rock from Mars into interplanetary space.

About thirteen thousand years ago the rock fell into the Antarctic ice fields as a meteorite. ” (Fix) This meteorite was carefully studied for two years, revealing several different types of evidence of primitive life on the red planet. “Another piece of evidence was the discovery of inorganic compounds like iron sulfides that can be produced by bacteria and other terrestrial organisms. The most dramatic evidence, however, is tiny structures in the carbonate globules that resemble microscopic fossils of ancient terrestrial bacteria. (Fix) Life may be closer than we think, but it also may have died out eons ago when the liquid water on the surface of Mars seemingly refused to stay in liquid form any longer. Titan, or Saturn VI, the largest Moon of Saturn, and second largest moon in the Solar System, seems promising for handling life. While being much cooler than our own planet, again, organisms that live there could adapt to the temperature, as well as atmospheric pressure it sustains; a pressure of 1. 6 bars, 60% than greater that of Earth. Titan’s atmosphere brings interesting points to itself because of its composition. Titan’s air is predominantly made up of nitrogen with other hydrocarbon elements which give Titan its orange hue. These hydrocarbon rich elements are the building blocks for amino acids necessary for the formation of life. Scientists believe that Titan’s environment may be similar to that of the Earth’s before life began putting oxygen into the atmosphere. ” (Hamilton) This means that life on Titan has a potential to begin as it did theoretically on Earth, or could even have already even begun in very early stages, although these organisms would have to be highly resilient if they are anything like us. Titan’s surface temperature appears to be about -178°C (-289°F)… scientists believe lakes of ethane exist that contain dissolved methane. Titan’s methane, through continuing photochemistry, is converted to ethane, acetylene, ethylene, and (when combined with nitrogen) hydrogen cyanide. The last is an especially important molecule; it is a building block of amino acids. ” (Hamilton) Europa, a moon of Jupiter, is another highly considered candidate for life. Its surface is covered completely by a shell of ice, cracked and scarred by tidal forces deep beneath.

The moon’s tidal forces “raise and lower the sea beneath the ice, causing constant motion and likely causing the cracks we see in images of Europa’s surface from visiting robotic probes. This “tidal heating” causes Europa to be warmer than it would otherwise be at its average distance of about 780,000,000 km (485,000,000 miles) from the sun, more than five times as far as the distance from the Earth to the sun. The warmth of Europa’s liquid ocean could prove critical to the survival of simple organisms within the ocean, if they exist. (Harvey&Burdick) This ocean, thought to p globally “with more than twice the volume of Earth’s seas,” may have deep hidden secrets, “with conditions that might not be completely alien to some forms of life on Earth. Under its frozen crust, Europa may harbor the key ingredients required to create a habitable environment. ” (Harvey) Europa’s closer, though still very far distance from the sun, along with what may be hidden in its ocean, make it possibly a better candidate for life within our own star system.

One great physicist, Stephen Hawking, believes the possibility of life outside of our planet is too great to ignore. He jokes that “Primitive life is very common and intelligent life is fairly rare. ” Although he is very fond of the theory of extraterrestrial beings, he does warn us heavily about them. “We should be careful if we ever happen upon extraterrestrial life… Alien life may not have DNA like ours: ‘Watch out if you would meet an alien. You could be infected with a disease with which you have no resistance. What we normally think of as ‘life’ is based on chains of carbon atoms, with a few other atoms, such as nitrogen or phosphorous… we can imagine that one might have life with some other chemical basis, such as silicon. ” (dailygalaxy. com) Life to him seems undeniable in other parts of the universe, but he does suggest logically that it just may very likely not be like us. This theory is to be respected, because many planets and subterran objects may fall in every planetary guideline to support life, just not in the way we see it in ourselves.

Life must exist elsewhere, whether it be out neighbor, next door or down the block, or whether it be outside of our closely knit family of planets, moons, asteroids, etc. It could host similar structure to our own, or be composed differently, and therefore could survive completely different conditions from our own. Simply put, it may be considered to be foolish to completely ignore the possibilities of any terran planet to sustain life, because life is almost certainly out there somewhere, and it may be the in last place we think to look. Works Cited Crowe, Micheal J. The Extraterrestrial Life Debate 1750-1900.

Cambridge UP. 1986. Print. Fix, John D. Astronomy: Journey to the Cosmic Frontier. 5th ed. New York: McGraw-Hill. 2008. Print. Hamilton, Calvin J. “Views of the Solar System: Titan. ” solarviews. com. Solarviews, 2011. Web. 10 Apr. 2013. Hart, Stephan. “Bacteria: Survival in Siberia” astrobio. net. Astrobiology Magazine, 2002. Web. 10 Apr. 2013. Harvey, Samantha and Autumn Burdick. “Solar System Exploration. ” nasa. gov. NASA, 2013. Web. 10 Apr. 2013. “Stephen Hawking on the Possibility of Non-Carbon-Based Extraterrestrial Life. ” dailygalaxy. com. The Daily Galaxy, 2009. Web. 10 Apr. 2013.