Life on Other Planets free essay sample

Life on other planets, Is there another titan planet out there that harbors life? Scientist have found two such planets in a neighboring but distant Solar System. Which planets are habitable and is there already life there or basically in general, â€Å"Is there life in outer space? † That is the question and debate among astrologists and scientist alike about this discovery of two planets that orbit the red dwarf star of Gliese 581 (Gliese 581c. eu). The fascination of intelligent life other than us has led to many studies and theories. With recent discoveries about the universe and the finding of Gliese 581, the idea of intelligent life has become even more intriguing. The implications of proving life exists on other planets and communicating with them could have an enormous impact to our society. The following discusses the possibilities of life on other planets by studying what sustains life on planet Earth, possible life within our Solar System, the discovery and study of other life bearing planets, examines what criteria may sustain life in other stars systems, and current programs studying extraterrestrial life (Koch and Borucki, 1996). Recent technological advancements have confirmed the existence of relatively large planets around other stars. Earth-like planets orbiting other stars have yet to be discovered, but most astronomers believe one will be found. In order for a star to maintain a potentially life-giving planet within its orbit certain criteria would have to be established and maintained. Stars have been classified by The Harvard one-dimensional temperature classification scheme (based on hydrogen Ballmer line strengths) was developed in Harvard College Observatory in 1912 by Annie Jump Cannon and Edward C. Pickering (Koch and Borucki, 1996). This classification is ordered from hottest to coldest, comparing mass, radius and luminosity to our Sun. Stars are catalogued by the letters O, B, A, F, G, K, and M. These star types span the range of star temperatures. Spectral type is determined strictly by temperature: O type stars are the hottest stars and M type stars are the coolest. Stars within the classification of â€Å"O†, â€Å"B†, and â€Å"A† are considered to massive and have very short life spans to allow primitive life forms to emerge. K† and â€Å"M† stars are considered to be too dim and would create little solar radiation for a habitable planet to evolve unless the distance was as close as Mercury is to the Sun. Any other type planet would be too cold to support life. Our Sun is presently a G-2 class Star, which because of size and photospheric temperature is best suited for sustaining life as we humans understand it. Different stars within the classification of F and G vary from white or yellow-white stars with medium to weak hydrogen lines have been researched by astronomers as potentially being conducive to the development of life. This type of region would be considered, †The Habitable Zone†. The Habitable Zone is a region surrounding a star throughout which the surface temperatures of a planet would be ideal for life formation and be life sustaining (Kasting, Whitmire, Reynolds 1994). With this technology, humankind has made advancements that enable more accurate research and validation to the science of astronomy. Scientists worldwide are involved in research of location and identification of new planets and unexplained occurrences within the universe, along with exploration of life on other planets. Space travel performed by organizations such as NASA are assisting in dispelling many myths about our current solar system and the existence of life on any of these other planets, while organizations such as Meta Research Inc. is dedicated to ruling out unnecessary theories and updating the ideas and predictions while educating students of the stars with updated facts and ongoing programs. 28 new Exoplanets outside our solar system were found and identified (Choi, C. Q. , 2011), bringing the total to 236 known Exoplanets. After a new study that says, â€Å"worlds that orbit red dwarfs, and even rogue planets with no stars to call home, might have surface oceans loaded with organic compounds, making them similar to Saturns moon, Titan. † Titan is the only known moon that has a thick atmosphere, and the only world besides Earth to have liquid on its surface. To see if worlds like Titan could host oceans when not orbiting Saturn, McKay and planetary scientist Ashley Gilliam calculated what a Titan-like world might be like while orbiting around a relatively dim M4 red dwarf star. The seas of Titan are made of liquid methane, often leading to speculation as to whether or not they could host life, much like how life on Earth depends on water. Such aliens would consume organic compounds just as Earth life does, but inhale hydrogen gas in place of oxygen and exhale methane instead of carbon dioxide (Choi, C. Q. , 2011). The reason we chose to look at red dwarf stars is because they are the most abundant stars in the galaxy, Gilliam said. It is much more likely that we would find another Titan-like world orbiting an M-star than we would orbit a star like our sun. The researchers also calculated what Titan could be like orbiting a slightly hotter M3 red dwarf star, such as Gliese 581. A number of planets have already been detected near it now. We chose to look at Gliese 581 because we believe that it could support a Titan-like world as a moon of one of the giant planets, and thus could already be supporting a world with comparable conditions to Titan, Gilliam said. The light from a red dwarf star has more infrared than our sun does. More of this starlight would reach Titans surface, because its atmospheric haze is more transparent to infrared wavelengths. If Titan was placed at a distance from these red dwarfs so that it received the same average amount of light as it received from the Sun, the scientists estimated this extra infrared could warm its surface by about another 10 degrees C. Due to flares, red dwarf stars can generate more particle radiation and specific kinds of ultraviolet rays than our sun does. This could potentially generate more haze in a Titans atmosphere, which would then block sunlight and keep the planet cooler. Nevertheless, liquid seas would be possible, the investigators found such oceans would exist if Titan was 8. to 23 percent of an astronomical unit, which is the distance the Earth is from the Sun, or from an M4 red dwarf, and 63 percent to 166 percent of an astronomical unit from Gliese 581. If Titan was a rogue planet with no star to call home, the researchers wondered if it could still be covered in seas due to geothermal heat. The researchers calculate Titan would need to release about 20 times more geothermal heat than Earth does to keep its current surface temperature, which is unrealistic for a world its size. However, if its atmosphere was 20 times thicker than current levels, it could retain enough heat to still have surface oceans. It is not clear how much atmosphere a rogue planet would have, McKay cautioned. In order for a starless planet to have liquid methane seas on its surface, a more realistic scenario might be for it to be both larger and warmer than Titan and have a thicker atmosphere, he suggested (Choi, C. Q. , 2011). Organizations such as the Search for Extraterrestrial Intelligence (SETI) continue to search for other life forms that exist throughout the universe. Ongoing studies and research for microbial and non-intelligent forms of life (Choi, C. Q. , 2011) have been ongoing for many years and studies are being conducted for the search of intelligent forms of life rather than limiting the search for microbial and spectroscopic life forms. Light and radio waves travel at a slow rate throughout the never-ending universe, making contact with possible intelligent life forms from other planets almost impossible. â€Å"We must admit that in space there are other globes, other races of men and animals† (Lucretius, 1977). Over two thousand years ago Titus Lucretius Carus was certain there was life elsewhere in the Solar System and he was not the only person to assume this. Many scientists and philosophers around this time, and even present day scientists and philosophers, would have agreed with his statement. Roughly one and a half thousand years later, Galileo found spots on the Sun plus he distinguished the movement of the mountains and seas of the moon through his telescope; could these be indicators for life elsewhere? After these findings by Galileo, people strongly believed the moon â€Å"hosted living beings† (Genta and Rycroft, 2003) but this idea was cut short when scientists sadly proved the moon had no atmosphere; for a planet to have life it must have an atmosphere. When searching for life in the past, scientists used 2 different types of method. The first method was sending space probes out with Earth and following its journey around specific planets. A space probe has helped scientists understand more about the solar system and is used to give a rough idea to a possible indication of life on other planets. Space probes are unmanned spacecraft which relays information that helps scientists be aware of the weather and other changes which happen out with our planet Earth. Moreover, space probes are sent to the solar system with enough energy to fly though the gravitational field of planet earth and the advanced technology built in helps the space probe find its way around the solar system. Some space probes fly out to the Solar System and do not return to earth whilst others stay within in the solar system orbiting around a specific planet for a long period of time. Space probes which orbit around a planet helps scientists have took snapshots of the planet for scientists to study and decide whether or not life could be present there however analyzing the data provided by the space probe takes months, even years but because the chances of life to be found elsewhere is thin, to find life by using space probes scientists have to wait for ‘interstellar exploration missions’ (Genta and Rycroft, 2003) which lead to the creation to search for Extraterrestrial Intelligence (SETI) instead of searching for extraterrestrial life. The changes in searching from extraterrestrial life to extraterrestrial intelligence may help the scientific community gain more results on searching for extraterrestrial life proves much easier to accumulate plus life, means something is living, intelligence is looking for signs that something has lived or is living without actually seeing it therefore, if something is found when searching for extraterrestrial intelligence, scientists could astonishingly find life elsewhere within the solar system. To search for extraterrestrial intelligence, scientists use radio telescopes to try and pick up any transmissions from planets orbiting stars such as Gliese 581. Some of the research carried out by scientists has been conducted in the visible and near infrared part in the electromagnetic spectrum, most of the SETI experiments have been conducted by scanning our sky using the complex radio telescopes for a possible signal of direct contact from other species through all these trans missions. As the search for extraterrestrial intelligence has been based around two different approaches, first approach was the radio telescope that was used and set toward a specific star. The star which was chosen was because of the stars close resemblance to our Sun. Scientists problem so far is that they did not know what frequency the extraterrestrial intelligence are using, so there had to be a high number of channels in the receiver if they hope to pick up one frequency. There is only one problem with catching these signals is the interference with other objects with in our atmosphere so this method is not as efficient as everyone had hoped. The next method that used was to look at observations of signals of a â€Å"non-natural origin†(Genta Rycroft, 2003)†. However this method was extremely costly and has a limited coverage of our sky which again proved disappointing. â€Å"Radio astronomers who found themselves at the front line in a brand new research field which, was way beyond their scientific research†, Genta and Rycroft state that, â€Å"radio astronomers tried their best to find life using these complicated pieces of technology. † The implications of proving life exists on other planets and communicating with them could have an enormous impact to our society.