Extraterrestrial Life Extraterrestrial life has long been sought

Extraterrestrial Life    Extraterrestrial life has long been sought after by humanity. Ancient civilizations have depicted beings from the stars across the globe for thousands of years. As science has advance humanity has been able to expand their reach to the cosmos and begin the quest for extraterrestrial beings.  But where should the search begin? What exactly are scientists looking for? Does the technology exist for scientists to actively make advancements in the search? Through believers and non-believers, theories are being brought to the table to prove or disprove the existence of extraterrestrial life, and as civilization advances, the answers could become much more clear.     Based on what is known about Earth, scientists theorize the existence of life elsewhere in the universe, but is life possible in non earth-like conditions? It is speculated that since life on Earth is carbon based that this must be true throughout the universe. However, some biochemists believe that there are several atoms that could produce life in the proper non earth-like conditions, such as arsenic for example.  In 2010 NASA expanded on the definition of life when their researchers discovered a microorganism on Earth that is able to not only live but thrive using arsenic (“Discovery of “Arsenic-bug” Expands Definition of Life”, 2010). The Arsenic-bug is a microorganism that was found in California’s Mono Lake, which NASA chose to research due to its high salinity and high levels of arsenic, basically unlivable conditions. Ed Weiler, NASA’s associate administrator for the Science Mission Directorate, hit the nail on the head when he stated that, “…we have to think more broadly, more diversely and consider life as we do not know it.” If an organism on earth is capable of supporting itself using arsenic the scope has to be broadened in the search for extraterrestrial life.    It is estimated that over 500 planets in the Milky Way Galaxy are located within the “habitable zone.”  The habitable zone defined by the distance from a star where a planet can have liquid water on its surface. A planet in this zone will be far enough away from its parent star, such as Earth’s Sun so that it’s water does not simply evaporate. But this planet will also be close enough to its parent star that its surface water does not freeze ((Kovo, 2017).  Another way scientists are able to search for extraterrestrial life in non earth-like conditions is to explore planets outside of the habitable zone. Planets covered in ice could have had lava cores in the past that allowed them to have liquid water and perhaps support life, which could have traces left within the ice (Conditions That Support Life, n.d.). Scientists use freezers to preserve microorganisms. An associate professor at Louisana State University, Brent Christner, has actually revived bacteria from the bottom of the Guliya ice cap that dates back 750,000 years (Brown, 2013). Clearly, organisms can survive being frozen which makes exploring planets outside of the habitable zone another reason to broaden the scope of the search for extraterrestrial life.    Scientists are also able to scope out habitable planets by examining their atmosphere. Examining a planet’s atmosphere is less complicated than it may seem. Scientists use instruments to measure the heat and light reflected off of a planet to determine it’s atmosphere. The star that the planet being researched is orbiting emits heat that will be absorbed by the planet. Furthermore, the star’s self-generated light will reflect off the surface of the planet which allows for scientists to see what is going on in that planet’s atmosphere using inferred light and thermal imaging (“Using Light to Study Planets Activity | NASA/JPL Edu”, 2017). Using tools such as thermal imaging can help scientists find the most probable locations that could support life.    What will extraterrestrial life be like when it is found? Seth Shostak, from the Search for Extra-Terrestrial Intelligence (SETI) Institute believes scientists are far more likely to find non-intelligent life, such as microbial life, much sooner than finding intelligent life (Osborne, 2017). Microbial life is more likely because a large variety of conditions can support microbial life. Intelligent life will be much more difficult to find. Intelligent life is currently characterized by beings that are self-aware, use tools, and have language skills. Some scientists believe that comparing intelligent life to human abilities is missing the mark though. Denise Herzing, a dolphin researcher, suggests that beings without limbs which are able to manipulate their surroundings are able to move their mouths to make sounds or even have the brain capacity to process information can still be classified as intelligent life (Berreby, 2017). The fact is until intelligent life is found, scientists do not know what exactly it will be like.    Stephen Hawking has recently voiced his opinion on the search for intelligent extraterrestrial life. Hawking believes that blindly sending signals into space could potentially be a bad idea. That contact with intelligent beings could be hostile. Shostak is currently part of that same debate, whether Earth should be sending messages into space in the hope of finding alien life. Shostak believes that intelligent beings could be so far away from Earth that any messages sent out into the universe could take thousands of years to be intercepted. Additionally, a response back from intelligent life, if any response, could take even longer to be sent back. A big question about sending these signals is what is the risk? Since scientists have not found life elsewhere there is no clear answer.     Does extraterrestrial life exist? As of today the existence of extraterrestrial life is completely hypothetical, meaning there is no proof. That doesn’t keep the idea of life elsewhere from being widely accepted by the scientific community. Scientists are actively perusing new methods to detect other life in the universe. For some, zeroing in on a planet that most resembles Earth is the best option because Earth has spawned life in so many forms. NASA uses the Kepler telescope to zero in on planets in the habitable zone of stars resembling Earth’s Sun, in hopes of finding Earth’s “twin.” The discovery of Kepler-452b is the closest scientist have come to accomplishing finding an Earth-like planet. It is located in the habitable zone and has a sun similar to Earth. Additionally, it’s discoverers believe it has a similar rocky surface to Earth, and Kepler-452b is only one and a half times larger than Earth (Greicius, 2015). Finding earth-like planets seems like a logical place to start in the search for extraterrestrial life since scientists are able to utilize what is known about Earth to hypothesize the existence of life on similar planets. There are scientists that have a different approach to the search for alien life.     The Search for Extraterrestrial Intelligence, better known as SETI, is an exploratory science that searches for evidence of life elsewhere in the universe. The Center for SETI Research uses signal-processing technology to search for signals from advanced technological civilizations (The Center for SETI Research, n.d.). SETI believes that technologically advanced civilizations can be detected by radio waves. In 1997 SETI was given a grant by NASA to build the Allen Telescope Array which is a group of small dishes designed to “listen” to the universe for signs of life. The advantage of the Allen Telescope, as opposed to larger telescopes such as Arecibo Telescope, is that it can look at multiple stars at a time. The Arecibo Telescope can only focus on one star at a time. Another advantage of the Allen Telescope is that is has a significantly lower cost to build and are easily produced. The ability to search for life in the universe is greatly enhanced by the Allen Telescope Array. This method of detecting extraterrestrial life requires constant advancements in technology to broaden the scope of what scientists are looking for, and to allow every opportunity for a signal from extraterrestrials to be intercepted by Earth, and possibly the Allen Telescope Array.     With all the money and resources being delegated to the search for extraterrestrial life, what is to be said about people who believe life elsewhere in the universe is unlikely? Professor Brian Cox, an English physicist, and professor of particle physics in the School of Physics and Astronomy at the University of Manchester believes that whatever the process that lead to life on Earth was a fluke, and that humanity is completely unique. This view point does make sense as of now since there have not been any discoveries of life anywhere else in the universe so far. It is however very difficult to believe that with an entire limitless universe that not one other place has a sign of life. The likelihood of almost infinite possibility of places for life to spawn gives more hope to the idea then doubt.     Mohamed Noor, a professor of biology at Duke University, doesn’t believe humans are unique but suggests that there cannot be an estimate of the probability of life until there is a sample size of at least 2, one being Earth and the other being any other example of life in the universe. Just as humans have advanced from thinking the Earth was the center of the universe, nothing is known until there is proof. Professor Noor reminds scientists that without proof, there is no concrete answer to the question of if extraterrestrial life exists. As of now, it is all speculation, hypotheses, and educated guesses.       Of course, there are also the opinions and tall-tails of alien life forms visiting Earth and the government conspiracies trying to cover these visits from aliens up. The idea of a technologically advanced species visiting Earth is a fairly new idea that has stemmed only in the past century. In the 1800’s, after imaginations were being fueled by early science fiction writers, the first UFO sightings were being reported. Between 1897  and 1947 stories emerged claiming alien wreckages in Texas and New Mexico resulting in the recovery of an alien specimen. Of course, these stories proved to be false since no one could produce eyewitnesses, or more importantly, evidence. The New York Times reported last year that between 2007 and 2012 there was a secret U.S. Department of Defense program called the Advanced Aerospace Threat Identification Program (AATIP). The program was shut down in 2012 because, “there were other, higher priority issues that merited funding,” (Radford, 2017). The government was interested in UFO sightings because unidentified flying objects over American soil could have been some sort of threat from our enemies. Once disproved, the Air Force moved on to more important matters. The search for extraterrestrial life might be in full swing, but it can be agreed that no credible organization thinks aliens are already here.    Extraterrestrial life has long been sought after by humanity.  With the advancement of science and the relentless hope of believers, humanity is taking the first steps in discovering extraterrestrial life. Although the “how?” is not yet completely clear, the “why?” resonates with scientists and people of all beliefs. If life is found in the universe it could give humanity a clue as to how exactly life began, and how it evolved. Believers and non-believers are both equally as important to new discoveries because new and different ways of thinking are what will lead to answers and progress. As the search continues and technologies advance perhaps the answers will become more clear. For now, humanity is still looking to the stars searching for the answer to the ultimate question, are we alone in the universe?     References     Berreby, D. (2017, June 18). What Makes an Alien Intelligent? Retrieved January 14, 2018, from https://www.newyorker.com/tech/elements/what-makes-an-alien-intelligent    Brown, P. (2013, October 10). Colder Than Ice: Researchers Discover How Microbes Survive in Subfreezing Conditions. Retrieved January 13, 2018, from https://blogs.scientificamerican.com/guest-blog/colder-than-ice-researchers-discover-how-microbes-survive-in-subfreezing-conditions/    Conditions That Support Life. (n.d.). Retrieved January 13, 2018, from http://learn.genetics.utah.edu/content/astrobiology/conditions/    Discovery of “Arsenic-bug” Expands Definition of Life. (2010, December 2). Retrieved January 13, 2018, from https://science.nasa.gov/science-news/science-at-nasa/2010/02dec_monolake    Greicius, T. (2015, July 23). Finding Another Earth. Retrieved January 14, 2018, from https://www.nasa.gov/jpl/finding-another-earth    Kovo, Y. (2017, February 14). Habitable Zones of Different Stars. Retrieved January 13, 2018, from https://www.nasa.gov/ames/kepler/habitable-zones-of-different-stars    Osborne, H. (2017, October 03). Alien-hunting astronomer says we’ll find intelligent extraterrestrial life in the next 20 years. Retrieved January 14, 2018, from http://www.newsweek.com/seti-seth-shostak-alien-life-discovered-20-years-676301    Radford, B. (2017, December 20). UFO Sightings & News. Retrieved January 14, 2018, from https://www.livescience.com/20645-ufo-sightings.html    The Center for SETI Research. (n.d.). Retrieved January 14, 2018, from https://www.seti.org/centerforseti    Using Light to Study Planets Activity | NASA/JPL Edu. (2017, May 16). Retrieved January 14, 2018, from https://www.jpl.nasa.gov/edu/teach/activity/using-light-to-study-planets/