1,710 research outputs found
Jarosite stability on Mars
No full textJarosite, a potassium (sodium) iron sulphate hydrated mineral, has recently been identified on the martian surface by the Opportunity rover. Using recent thermochemical data [Drouet and Navrotsky, 2003, Geochim. Cosmochim. Acta 67, 2063–2076; Forray et al., 2005, Geochim. Cosmochim. Acta, in press], we calculate the equilibrium decomposition curve of jarosite and show that it is thermodynamically stable under most present martian pressures and temperatures. Its stability makes jarosite potentially useful to retain textural, chemical, and isotopic evidence of past history, including possible biological activity, on Mars
Development of life marker chip technology for in-situ life detection on Mars
No full textThe European Space Agency (ESA) is currently developing its flagship Life Detection Mission, ExoMars, which is scheduled to fly to Mars in 2013. The primary goal of this mission is to compliment the Phoenix NASA mission in confirming the presence of organic material on Mars, and, for the first time, analyse this organic material to determine the presence of organic species indicative of presence of past or present Life. One of the proposed Life detection technologies is the Life Marker Chip (LMC), which uses immunoassays with fluorescent readout to detect small organics and proteins in a microarray format within microfluidic channel structures. This PhD thesis encompasses the work done by the author on the development of the SMILE LMC during the period prior to, and during part of the first phase of, the Life Marker Chip Technology Readiness Level Upgrade Study funded by ESA from 2005 and 2007. Cont/d
The Spread of Batrachochytrium Dendrobatidis and its Effect on the Global Amphibian Ecosystem
No full textThe Spread of Batrachochytrium Dendrobatidis and its Effect on the Global Amphibian Ecosystem, discusses the deadly amphibian pathogen Batrachochytrium Dendrobatidis. My work aimed to answer the question, How did the spread of batrachochytrium dendrobatidis, affect amphibian populations from its discovery in 1993 to modern day, and how could it affect biodiversity in the future? It first covers a brief history of the disease and its discovery as well as the impacts it has on individual hosts. I then discuss the effects that the parasitic fungus has on biodiversity, concluding with ways for individuals and communities to mitigate the impacts that chytrid has upon the ecosystem.
Faculty Sponsor: Deborah Livel
Cupid & Psyche
No full textThe Tale of Cupid and Psyche was a research topic easily curated by the three of us. We as a collective decided upon which rendition of the story we would like to reference from, as well as represent details from other renditions that fit our analysis. We all had specific details in mind that we wanted to discuss and represent, specifically Cupid\u27s relation to Venus as well as Psyche\u27s butterfly wings. Before we began conversing on ideas about individual topics, we all discussed what the story meant to us, and why we wanted to research it. Our biggest inspiration was the idea that this was Luna\u27s bedtime story, something so beautifully attached to her childhood that she wanted to represent the story and discuss it in further detail. Mars and Leo were both interested in the story for various reasons, but the sentiment Luna had solidified the decision on Cupid and Psyche.
Faculty Sponsor: Lisa Higgin
Thermochemistry of yavapaiite KFe(SO4)2: Formation and decomposition
No full textYavapaiite, KFe(SO4)2, is a rare mineral in nature, but its structure is considered as a reference for many synthetic compounds in the alum supergroup. Several authors mention the formation of yavapaiite by heating potassium jarosite above ca. 400°C. To understand the thermal decomposition of jarosite, thermodynamic data for phases in the K-Fe-S-O-(H) system, including yavapaiite, are needed. A synthetic sample of yavapaiite was characterized in this work by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal analysis. Based on X-ray diffraction pattern refinement, the unit cell dimensions for this sample were found to be a = 8.152 ± 0.001 Å, b = 5.151 ± 0.001 Å, c = 7.875 ± 0.001 Å, and β = 94.80°. Thermal decomposition indicates that the final breakdown of the yavapaiite structure takes place at 700°C (first major endothermic peak), but the decomposition starts earlier, around 500°C. The enthalpy of formation from the elements of yavapaiite, KFe(SO4)2, ΔH°f = −2042.8 ± 6.2 kJ/mol, was determined by high-temperature oxide melt solution calorimetry. Using literature data for hematite, corundum, and Fe/Al sulfates, the standard entropy and Gibbs free energy of formation of yavapaiite at 25°C (298 K) were calculated as S°(yavapaiite) = 224.7 ± 2.0 J.mol−1.K−1 and ΔG°f = −1818.8 ± 6.4 kJ/mol. The equilibrium decomposition curve for the reaction jarosite = yavapaiite + Fe2O3 + H2O has been calculated, at pH2O = 1 atm, the phase boundary lies at 219 ± 2°C
Mars Project
No full textabstract: This thesis presents the moral and ethical controversy surrounding the possibility of terraforming Mars and provides an overview of the 5 characteristics of Mars that can kill you – radiation, low atmospheric pressure, carbon dioxide, freezing temperatures, and dust – should man embark on the journey. It presents these issues in written form, by storyboard, extensive graphics, and in a WIKI.
Ethical Considerations: The thesis presents the three main threads of thought regarding terraforming – that we should because it is there and man – superior to all other forms of life – wants challenges; that we should not since we are not superior to other forms of life and have no right; and the middle position – that we should be able to terraform Mars only if we clean up our act on Earth first. This is the point of view taken by the author of the thesis.
5 Ways Mars Can Kill You: the essay portion of the thesis is an overview of the research regarding the main obstacles to terraforming Mars and potential solutions.
Storyboard: Depicts the ethical efforts one must achieve before traveling to Mars as well as the process of terraforming – all images in chronological order.
Graphics: A series of Illustrator/Photoshop graphics moves the reader through the problems we have here on Earth that must be solved before terraforming, the process of getting to Mars and the activities involved in making her inhabitable for man.
WIKI: The WIKI showcases thesis material in a more interactive manner. JavaScript animations run throughout the WIKI and the user is able to create posts within the website – which acts as a forum
Graveyard orbits for future Mars missions
No full textMars is expected to become a focal point of exploration (human and robotic) in the coming century, with a very likely need for a robust space infrastructure. Be it communication and navigation satellite constellations or scientific missions in low Mars orbits (LMO) and Areosynchronous orbits (ASO), every individual satellite will have a definitive period of operation after which it becomes derelict. At the end-of-life (EOL) the satellite shall be proactively dealt with in a sustainable manner to protect our access to the space environment of Mars and opportunities to use this. Clearly, impacting Mars or escaping Mars’ gravity are no viable options. This paper aims at identifying graveyard orbit solutions in circummartian space for future Mars space debris. Orbital stability for a period of 200 years is studied for Martian orbits using the symplectic integration technique. Extensive validations are performed and propagation and integration settings are tuned to suit a variety of configurations. A plethora of candidate graveyard orbit solutions are found and presented for orbits in the ASO and LMO regimes. For example, it is found that transferring an ASO satellite to 400 km below the nominal orbit altitude would ensure a stability margin of ±25 km for at least 200 years. Multiple orbital geometry characteristics (combinations of semi-major axis, inclination, right ascension of ascending node), satellite geometries (various values of area-to-mass ratio) and uncertainties are studied to produce a comprehensive analysis of long-term stability of potential graveyard orbits around Mars, making them attractive for such purposes. The protected zones are found to be safe from debris even for an uncertainty in initial eccentricity of 0.01 and variations in cross-sectional area due to uncontrolled tumbling. The overall objective of this paper is to make designers of future missions to Mars aware of the EOL aspects and include this in their mission design proposals at an early stage already.Astrodynamics & Space Mission
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