Search Site for Life on one Titan, the Saturns through an Unmanned Landing Mission - Term Paper Example

Lander Project Proposal on a search site for life on one Titan, the Saturn’s through an unmanned landing mission Table of Contents Lander Project Proposal on a search site for life on one Titan, the Saturn’s through an unmanned landing mission 1 Table of Contents 1 Science aims and strategy 3 Aim of the proposal 3 Why only Titan? 3 Previous explorations 4 Suggestive information on life on Titan 5 Ancient or extant life on Titan 6 Geology 7 Titan geology 7 Geology of the chosen site 7 Type of site 8 Nature of expected evidence 8 Logistics 9 Topography of the selected region 9 Engineering requirements 10 Sampling and detection techniques 11 References 12 Science aims and strategy Aim of the proposal Saturn is popularly known for its rings but that it has dozens of icy moons, ranging from Mimas to Rhea, is of notable interest to astronomers and space scientists. This is a proposal that is on a search site to one of Saturn's moons, Titan, for life through an unmanned landing mission. Titan is the largest moon of Saturn. Of all the 62 moons that it has, Titan is bigger than the planet Mercury. Most of the other moons range from being smaller moonlets of around one kilometer in diameter to those having a diameter of more than 50 kilometers. Titan has nitrogen-rich atmosphere, very much like that of earth's moon, and is the second largest in the solar system. The greatest feature of Titan is its tomography, which is full of dry river networks and hydrocarbon lakes. The proposal has selected Titan for more reasons than one. It was discovered by Christiaan Huygens in 1655 by using an objective lens of 2.2 in (57-millimeter) diameter. Discovery of rest of the moons took place thereafter. Why only Titan? The proposal to look for life only on Titan derives its strength from the fact that this moon has been discussed frequently with regard to life which it predictably sustains. The moon's life-sustaining chatter was recently put to scientific tests by the Jet Propulsion Laboratory of NASA in Pasedena, California. The results have been startling because they have belied earlier presumptions that no life was possible on Titan. The experiment done by NASA was one of its kind since it simulated a Titan-like atmosphere in the laboratory and studied complex organic chemistry and revealed the existence of prebiotic materials being sustained by the moon. Prebiotic materials, it is noteworthy, identified first in 1995 by Marcel Roberfroid, are non-digestible ingredients that are responsible for the bacterial activity in the atmosphere in which they thrive (Gibson and Roberfroid, 1995). It has previously been held that Titan's surface has been dull and inert. Murthy Gudipati of NASA has remarked that what could be driving life on Titan is almost the same what drives life on earth; similar type of biological chemistry. The only difference is that Titan does not receive as much light from the sun as earth does and is relatively much colder than this planet (Burns, 2013). Cornell University's Jonathan Lunine has wondered if Titan would be harbouring "exotic life'. This is because Titan has shown existence of floating ice on its surface in the form of seas and lakes. Mostly thought of as floating hydrocarbon ice, this is being thought will shed more light along the liquid-solid boundary. The boundary, when understood correctly, might prove as the first step towards proving terrestrial life on Saturn's moon (PTI, 2013). Previous explorations One of the most important explorations carried so far to study Titan and/ or Saturn and its moons was Cassini Huygens, which was a NASA-ESA-ASI robotic spacecraft that entered solar system of the Saturn. This spacecraft arrived into Saturn's system in 2004; it took it almost 8 years to reach there after it was lainced in 1997. Cassini–Huygens had two parts: one lander, called Huygens and an atmospheric probe. In 2005 the lander was there on Titan's surface and was expected to be stationed there until this year. Soon after its landing there, it started transmitting data back to earth. This was teamwork of 16 countries that participated in this mission; all of which have been responsible in designing Cassini, the orbiter and Huygens, the probe, along with its building, data collection and initial flying. Jet Propulsion laboratory, however, manages the whole mission. When this mission got extended (first in 2008 and then in 2010), it was renamed as Cassini Equinox Mission, and it is expected to be operational until 2017. At the time of its second extension it was renamed again; this time as Cassini Solstice Mission. Initially the mission was designed to meet certain primary objectives. These included determining the dynamic behaviour of Saturn rings and its three-dimensional structure; ascertaining geological history of several Saturn components; determining the satellite surface compositions; study the dark material on the surface of Lapetus (one more of Saturn's moons); analyse magnetosphere and its three-dimensional structure; collect data on Saturn's cloud level and its atmosphere; see what makes hazes around Saturn and make a regional scale characteristics of Titan's surface. Powered by a plutonium power source, since solar arrays were not feasible because of the distance to be travelled by the Cassini-Huygens, it was fitted with the most state-of-the-art equipments like Cassini Plasma Spectrometer (CAPS), Cosmic Dust Analyzer (CDA), Composite Infrared Spectrometer (CIRS), Ion and Neutral Mass Spectrometer (INMS), Imaging Science Subsystem (ISS), Dual Technique Magnetometer (MAG), Magnetospheric Imaging Instrument (MIMI), Radar, Radio and Plasma Wave Science instrument (RPWS), Radio Science Subsystem (RSS), Ultraviolet Imaging Spectrograph (UVIS), and Visible and Infrared Mapping Spectrometer (VIMS) (Barber, 2010), Suggestive information on life on Titan Research and evaluation are in the process and the question still remains open to introspection. However, in whatever little evidence that has been collected so far, the life on Titan either that existed or that does exist could be presumed keeping in view the following factors. It is widely held that the moon could be providing a atmosphere which can support non-water-based life. This is because the Titan's lakes, seas and rivers are either liquid methane- or ethane-based. The Cassini probe sent evidence that beneath the ice shell (Cook and Brown, 2012) which Titan has there could be storehouses of liquid water lurking there. That means if not the visible, but the sub-surface would be harbouring either ammonia (Fortis, 2000) or water. Titan is a natural satellite but the only one in this solar system which has an atmosphere which is fully developed. Its atmosphere, which is chemically active, thick, and rich in abundance of organic compounds, consists of more than trace gases. That gives an indication whether precursors in the form of chemicals would have existed there once. The presence of hydrogen gas on the surface environment and cycling through its atmosphere raises further evidence since it could be a source of energy if it mixed on the moon with any of the organic compounds like acetylene (Cook and Weselby, 2010; Adam, 2008: Chio, 2010). Ancient or extant life on Titan The ancient or extant life on Titan has been discussed particularly after the Cassini-Huygens mission provided evidence that life is or could have been possible on the moon. It is widely accepted that when phytochemically produced acetyline is hydrogenated, it is capable of providing metabolic energy which, in turn, is capable of fuelling near-surface organisms. Not only that, it also is able to replenish methane (Schulze-Makuch and Grinspoon, 2005). While whether or not life on Titan exists today is debatable because of its extreme low temperature of minus 289 degrees Fahrenheit, which makes it inhabitable for any life to sustain and progress biologically, yet it is of importance to look at the data published previously which hints that despite the odds there might still be locales out there which could be habitable. Besides this, as was revealed by papers presented by researchers from Washington State University and Southwest Research Institute (SwRI) at the Division for Planetary Sciences 2005, the presence of ample energy sources, organic molecules and liquid reservoirs on Titan's surface could have been a reason that ancient or extant life did evolve there. Geology Titan geology Titan has earth-like geology and since it is one of the peculiar moons in the solar system, it interests many specialists, which include climatologists, oceanographers and planetologists. Titan's atmosphere generates as much interest since it is rich in nitrogen and some methane. The air there is dense, as much as 4 times that of earth's and the pressure is nearly 50 percent more than that of earth. It is believed the sources of all these gases are within Titan itself. Its core is rocky and mantle made up of ice. The latter is said to be a combination of ammonia and methane. When hydrogen atoms are broken by the sunlight falling on its surface, the nitrogen stays on its surface and hydrogen drifts into its atmosphere. Nitrogen, it is noteworthy, is what makes up of most constituent of earth's atmosphere. Methane molecules fuse into each other and form heavier hydrocarbons like ethylene, ethane and acetylene. Titan, apparently, gets its freezing temperature. The Cassini probe relayed back puddles as detected by its radars, which is an indication that liquid bodies exist on Titan's surface. The Bubble Space Telescope even sent some pictures that showed changing cloud patterns over Titan. A 2000 kilometer, and several kilometer high large bright feature as captured on its surface is thought to be frozen ice, which nearly as half as that of Antarctica. Its brightness is explained as having been caused by ethane rain that must be washing its crud quite too often (Alden, nd). Geology of the chosen site This project expects to do research around the floating beds of ice on Titan's surface because that will be the starting point to go further deeper through on-site research and data collection with regard to oceans of water sloshing around this ice. This site also holds special meaning because Cassini during its six 2006 to 2011 fly-bys of the moon revealed distortions in its gravitational field. There was always something unusual happening within the moon, particularly in the inside than outside. This is strongly thought of as indicative of liquid water. Rome's La Sapienza University's Dr Luciano Less, an expert in the planetary sciences, has remarked: ‘Such a large response to the tidal field requires that Titan's interior is deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth (Waugh, 2012). These hidden oceans, as scientists have begun to believe, are a near match for life to evolve, even as doubts persists whether extreme low temperatures would allow it to thrive. Type of site As explained the site would be one that has floating ice strewn all around. This site, on account of these ice beds, would be reveal huge presence of methane and ethane seas, thus making it an exciting target to explore. This is because at such sites the expectations of presence of exotic life increase. This site, thus, will provide an opportunity to study interesting chemistry of the place on account of floating hydrocarbons. The site provides another interesting aspect because the icy bodies reflected by Cassini probe are stable in nature and not moving or temporary. Furthermore, it will be interesting to study precipitation patterns on Titan's surface because it is unlike that of earth's. On the latter the precipitation involves evaporation of water, but on the former it involves that of methane and ethane. Cassini, it must be noted has sent two different sets of data for northern and southern hemisphere. The latter has lakes spread sporadically and the former has these seas of hydrocarbons (NASA, nd). Nature of expected evidence As this project takes off successfully evidence can be expected on at least four parameters. The project will explore the whole system of work that prevails at Titan, throw more light on the moon's astrobiological potential and organic inventory, help in the development of Titan's evolution models and origin, and even help gather data on the moon's magnetosphere. On account of their abundance, methane reservoirs and cycle would be explored further and so would be the geography and surface composition of constituents found on the moon. One of the important evidence which can be expected from the project is study of tectonism and cryovolcanism in a hope that more light can be thrown on whether the moon had an active past or not. Evidence would relate to presence of ammonia, moon's magnetic field and the ion-formation chemistry doing on at the surface. This project will also pick up from where Cassini left in its mission; that will be the study of Titan's atmosphere anywhere between 400-900 kilometers above its surface. The Cassini also did not provide any substantial data on what happens to the gases in the long term which escape to the space and what seasonal changes are going on on the moon. The best evidence to be expected from the project would be to study its methane sea because scientists believe that Titan's methane cycle is a sort of Earth's hydrogen cycle analogue. A number of correlations can be established once the difference and similarities between the two are analysed. Logistics Topography of the selected region The selected region will be around Adiri, which is a bright region a little off the easternmost tip. This region has 'rivers' running through pale hills. The rivers seem to go down into plains from these hills which are made up of ice rocks. The hills have visible dark tops, presumably formed due to sun's ultraviolet radiation and concurrent methane rain, again descending into plains to form geological time scales. The plain area is dark and has pebbles and rocks, again that of ice. These rocks seem to be eroded over a period, which would be of interest to explore. Only chemical changes or friction can let that happen and it has to be seen which of the two factors are responsible for the same. Apparently some fluvial activity is going on in this area. In what is known of Titan so far, the topography of this place is suggestive of high levels of hydrocarbon ice. Engineering requirements Since this is a lander and not just orbiter, so its engineering requirements would be somewhat specialised. That is because solar panels would not be enough to power it due to Titan's distance from the sun. Its primary requirement would b an Advanced Stirling Radioisotope generator (ASRG). ASRG provides power supplies that live long is particularly useful for planetary missions and landed networks where solar panels prove to be inefficient. The ASRG will use Stirling power conversion technology and will be based on power generation from radioisotope. This system is currently under generation by NASA and United States Department of Energy and is expected to be potential use in space missions as this one. Cassini, it is worth mentioning here, used RTGs or radioisotope thermoelectric generators. These generators were also used by others missions like Pioneer, Viking, Ulysses, New Horizons and Galileo. The advanced form of RTGs, which offers an advantage over the same, is ASRG. The ASRG will use 0.8 kg plutonium-238, will have system efficiency of 30 percent, nominal power of 140 We, and equal to or greater than 14 year lifetime. The lander will be one part of the project; others will be an orbiter, one Montgolfier balloon and a rover. The latter will float in Titan's atmosphere, particularly clouds, for around 6 hours and then enable the lander to make a methane sea splashdown. The lander will relay data to the orbiter and will be fitted with instruments for radar profiling, imaging and instruments for atmospheric and surface profiling. The lander will be equipped with onsite data collection and analysis technology so that apart from relaying information to the orbiter, it can relay results as well. The ASRG will be activated only when the probe makes a splashdown. Till then the mission will use gravity assist fly-bys to reach its destination. The fly-bys will be provided by four assists of Earth-Venus-Earth-Earth and will take an estimated nine years to reach Titan. The probe will do experiments on Titan, by soil assessment techniques, for around 6 months. The rover will be designed on the basis of Lunokhod 1 model but greatly improvised and advanced. The project has chosen Lunokhod 1 because of its exemplary durability record of more than 3 decades. The improvisation will be done keeping in view Mars Exploration Rovers, notably MER-B Opportunity and MER-A Spirit. Its navigation will be propelled by a sun sensor and a star scanner so that it can determine its position with respect to stars and the sun. Sampling and detection techniques The probe will use several sampling and detection techniques. Plasma spectrometer will measure the electrical charge and energy of the particles that its rover's robotic arm will either pick up or encounter. Of special emphasis will be the measurement of molecules found on Titan's atmosphere. Magnetic field will also be determined. The probe will also see the existence of dust particles in the haze on the surface of Titan. It will use cosmic dust analyser for the purpose and measure speed, size and direction of dust particles if they exist. Even as temperature of the Titan is known, the rover will be fitted with a composite infrared spectrometer, which will measure compositions, thermal properties and temperatures of the objects by way of infrared waves emanating from the same. The same instrument will also measure distribution of clouds and aerosols along with gas composition in immediate touch with Titan's surface. Since Titan's atmosphere is charged with ions, the probe will carry an ion and neutral mass spectrometer. This will help analyse the behaviour and temperatures of ionic atmosphere on its surface. Right on front of the rover will be fitted an imaging science subsystem, which will be capable of taking both visible light and infrared shots. The relay system will send these images immediately to the orbiter, which will further transmit the same to the ground station on earth. Since Titan has been reported as having high objects, which is presumed as ice at the moment, an onboard radar right at the top of the rover will help determine their height. This will be accomplished when the radar sends out radio signals to different points on these objects and calculate their height by the bounce of their return, irrespective of the haze that surrounds the Titan’s surface. References Adam, H. (2008). "Scientists Confirm Liquid Lake, Beach on Saturn's Moon Titan", Scientific American magazine. Available http://www.scientificamerican.com/article.cfm?id=liquid-lake-on-titan. Accessed May 12, 2013. Alden, A, (nd). Geology of Titan. Available at http://geology.about.com/od/planets/a/aa061304a.htm. Accessed on May 12, 2013. Burns, C. (2013). Saturn’s moon Titan reveals even more life-sustaining possibilities. Available http://www.slashgear.com/saturns-moon-titan-reveals-even-more-life-sustaining-possibilities-03276349/. Accessed May 12, 2013. Barber, T. G. (2010). Insider's Cassini: Power, Propulsion, and Andrew Ging. Available http://saturn.jpl.nasa.gov/news/cassiniinsider/insider20100823/. Accessed May 12, 2013. Cook, J-R and Weselby, C. (2010). NASA News release, "What is Consuming Hydrogen and Acetylene on Titan?.” Available http://www.nasa.gov/topics/solarsystem/features/titan20100603.html. Accessed May 12, 2013 Choi, Charles Q. (2010). Space.com Magazine, "Strange Discovery on Titan Leads to Speculation of Alien Life". Available http://www.space.com/8547-strange-discovery-titan-leads-speculation-alien-life.html. Accessed May 12, 2013. Cook, J-R. and Brown, D. (2010). NASA News release, "Cassini Finds Likely Subsurface Ocean on Saturn Moon", Available at http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20120628.html. Accessed May 12, 2013. Fortes, A. D. (2000). "Exobiological implications of a possible ammonia-water ocean inside Titan". Icarus 146 (2): 444–452. Gibson GR, Roberfroid MB (Jun 1995). "Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics". J Nutr. 125 (6): 1401–1412. NASA.gove. (nd). Cassini. Available at http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20130108.html. Accessed May 12, 2013. PTI. (2013). Floating ice on Saturn's moon Titan may harbour 'exotic life' Available at http://www.indianexpress.com/news/floating-ice-on-saturns-moon-titan-may-harbour-exotic-life/1056904/#sthash.IX4mLa5u.dpuf. Accessed May 12, 2013. Schulze-Makuch, D. and Grinspoon, D. H. (2005), Biologically Enhanced Energy and Carbon Cycling on Titan? Astrobiology 5, 560-567; Clarke, R.N. et al. (2020), Detection and Mapping of Hydrocarbon Deposits on Titan, JGR-Planets. Icarus 178, 274-276. Waugh, R. (2012). Saturn's foggy moon Titan has oceans of water 'sloshing around' under crust of ice. Available at http://www.dailymail.co.uk/sciencetech/article-2166097/Saturns-foggy-moon-Titan-oceans-water-sloshing-crust-ice.html#ixzz2TMmkdDda. 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The boundary, when understood correctly, might prove as the first step towards proving terrestrial life on Saturn's moon (PTI, 2013). Previous explorations One of the most important explorations carried so far to study Titan and/ or Saturn and its moons was Cassini Huygens, which was a NASA-ESA-ASI robotic spacecraft that entered solar system of the Saturn. This spacecraft arrived into Saturn's system in 2004; it took it almost 8 years to reach there after it was lainced in 1997. Cassini–Huygens had two parts: one lander, called Huygens and an atmospheric probe.

In 2005 the lander was there on Titan's surface and was expected to be stationed there until this year. Soon after its landing there, it started transmitting data back to earth. This was teamwork of 16 countries that participated in this mission; all of which have been responsible in designing Cassini, the orbiter and Huygens, the probe, along with its building, data collection and initial flying. Jet Propulsion laboratory, however, manages the whole mission. When this mission got extended (first in 2008 and then in 2010), it was renamed as Cassini Equinox Mission, and it is expected to be operational until 2017.

At the time of its second extension it was renamed again; this time as Cassini Solstice Mission. Initially the mission was designed to meet certain primary objectives. These included determining the dynamic behaviour of Saturn rings and its three-dimensional structure; ascertaining geological history of several Saturn components; determining the satellite surface compositions; study the dark material on the surface of Lapetus (one more of Saturn's moons); analyse magnetosphere and its three-dimensional structure; collect data on Saturn's cloud level and its atmosphere; see what makes hazes around Saturn and make a regional scale characteristics of Titan's surface.

Powered by a plutonium power source, since solar arrays were not feasible because of the distance to be travelled by the Cassini-Huygens, it was fitted with the most state-of-the-art equipments like Cassini Plasma Spectrometer (CAPS), Cosmic Dust Analyzer (CDA), Composite Infrared Spectrometer (CIRS), Ion and Neutral Mass Spectrometer (INMS), Imaging Science Subsystem (ISS), Dual Technique Magnetometer (MAG), Magnetospheric Imaging Instrument (MIMI), Radar, Radio and Plasma Wave Science instrument (RPWS), Radio Science Subsystem (RSS), Ultraviolet Imaging Spectrograph (UVIS), and Visible and Infrared Mapping Spectrometer (VIMS) (Barber, 2010), Suggestive information on life on Titan Research and evaluation are in the process and the question still remains open to introspection.

However, in whatever little evidence that has been collected so far, the life on Titan either that existed or that does exist could be presumed keeping in view the following factors. It is widely held that the moon could be providing a atmosphere which can support non-water-based life. This is because the Titan's lakes, seas and rivers are either liquid methane- or ethane-based. The Cassini probe sent evidence that beneath the ice shell (Cook and Brown, 2012) which Titan has there could be storehouses of liquid water lurking there.

That means if not the visible, but the sub-surface would be harbouring either ammonia (Fortis, 2000) or water. Titan is a natural satellite but the only one in this solar system which has an atmosphere which is fully developed. Its atmosphere, which is chemically active, thick, and rich in abundance of organic compounds, consists of more than trace gases. That gives an indication whether precursors in the form of chemicals would have existed there once. The presence of hydrogen gas on the surface environment and cycling through its atmosphere raises further evidence since it could be a source of energy if it mixed on the moon with any of the organic compounds like acetylene (Cook and Weselby, 2010; Adam, 2008: Chio, 2010).

Ancient or extant life on Titan The ancient or extant life on Titan has been discussed particularly after the Cassini-Huygens mission provided evidence that life is or could have been possible on the moon.

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