Long-chain alkenones (LCAs) have been used for decades to reconstruct quantitative sea-surface temperature records, but they also have a great potential for paleotemperature reconstructions in lacustrine settings. Here, we investigated how the presence and abundance of LCAs in surface sediments from 106 lakes varied with environmental conditions in lakes of the Northern Great Plains (Canadian Prairies) in southern Saskatchewan, Canada. Consistent with preliminary research, we found LCAs in 55% of surveyed lakes, with mean concentrations of 143 μg/g dry sediment, but very high concentrations (up to 2.3 mg/g dry sediment) in 7% of lakes. Statistical analyses indicate that salinity and stratification play key roles in determining LCA presence and abundance supporting previous research in Spain and the northern Great Plains, USA. Overall, the alkenone unsaturation index () was not correlated significantly with average summer water temperature, probably because the timing of maximum LCA production occurs during the spring season. We conclude that improved seasonal sampling is required within the study lakes to better identify the timing and habitat of haptophyte production, and allow development of environmental temperature reconstruction tools.

<div class="page" role="region" data-page-number="1" aria-label="Page 1" data-loaded="true"> <div class="textLayer"><strong><span dir="ltr" role="presentation">1</span> <span dir="ltr" role="presentation">Abstract</span></strong></div> <div class="textLayer"><br role="presentation" /><span dir="ltr" role="presentation">Europa is one of the celestial bodies within our solar system that has the highest potential of harbouring life. </span><span dir="ltr" role="presentation">In this poster, we will discuss a method which will be used to help determine the survivability of life on Europa </span><span dir="ltr" role="presentation">and whether or not Europa has the appropriate chemistry necessary for life.</span> <span dir="ltr" role="presentation">Through subjecting regolith in </span><span dir="ltr" role="presentation">aqueous solution to UV/Visible radiation, and adopting a ’systems chemistry’ approach, the yield of organic </span><span dir="ltr" role="presentation">matter, more specifically amino acids, produced will be investigated to determine the prime conditions and </span><span dir="ltr" role="presentation">chemicals required for life on Europa.</span></div> <div class="textLayer"><br role="presentation" /><strong><span dir="ltr" role="presentation">2</span> <span dir="ltr" role="presentation">Introduction</span></strong></div> <div class="textLayer"><br role="presentation" /><span dir="ltr" role="presentation">As the ability to explore complexity and study planets and celestial bodies within our own solar system becomes </span><span dir="ltr" role="presentation">more feasible, it is increasingly practical to address the age old question of whether life can, or cannot, exist </span><span dir="ltr" role="presentation">outside of the Earth.</span> <span dir="ltr" role="presentation">With the forthcoming European Space Agency (ESA) JUpiter ICy moons Explorer </span><span dir="ltr" role="presentation">(JUICE) mission, the focus on the viability of life has been shifted onto the icy moons of Jupiter. The moons of </span><span dir="ltr" role="presentation">Jupiter (particularly Europa and Ganymede) have high potential for life and have become of particular interest </span><span dir="ltr" role="presentation">for research in the fields of Astrochemistry and Astrobiology.</span> <span dir="ltr" role="presentation">Specifically for the moon Europa, the interest </span><span dir="ltr" role="presentation">lies in whether the moon has the necessary chemistry for life to emerge, [3]. By performing a systematic study </span><span dir="ltr" role="presentation">of how Europan regoliths/salts react with plausible molecules after being irradiated and subject to similar </span><span dir="ltr" role="presentation">Europan conditions, the likelihood of life emerging on Europa can be quantified. With the potential discovery </span><span dir="ltr" role="presentation">of organics on the surface and near sub surface it is increasingly urgent to determine the composition and routes </span><span dir="ltr" role="presentation">to synthesis of these organics.</span></div> <div class="textLayer"><br role="presentation" /><strong><span dir="ltr" role="presentation">3</span> <span dir="ltr" role="presentation">Method</span></strong></div> <div class="textLayer"><br role="presentation" /><span dir="ltr" role="presentation">Samples of formulated Europan soil or salt analogues will be added to an aqueous solution of water and a molecule </span><span dir="ltr" role="presentation">that has been observed in the interstellar medium (ISM), [1]. With varying ratios of aqueous solution, mineral, </span><span dir="ltr" role="presentation">and ISM relevant molecule, the samples are irradiated with UV/Visible light using a range of wavelengths </span><span dir="ltr" role="presentation">(365nm, 425nm, 475-480nm, 650nm, and 6200K lamps) for periods of time ranging from 72 hours to 120 </span><span dir="ltr" role="presentation">hours.</span> <span dir="ltr" role="presentation">A statistical experimental design approach will be employed.</span> <span dir="ltr" role="presentation">The resulting residue using both high-</span><span dir="ltr" role="presentation">performance liquid chromatography mass spectrometry (LCMS) and gas chromatography mass spectrometry </span><span dir="ltr" role="presentation">(GCMS). A ’targeted’ methodology will be employed for the analyses specifically to determine if the analyte </span><span dir="ltr" role="presentation">contains amino acids, or any trace of amino acids, [2].</span></div> <div class="textLayer"><br role="presentation" /><strong><span dir="ltr" role="presentation">4</span> <span dir="ltr" role="presentation">Results</span></strong></div> <div class="textLayer"><br role="presentation" /><span dir="ltr" role="presentation">An initial screening run of this experiment using Martian, Earth, and Moon regolith revealed that the resulting </span><span dir="ltr" role="presentation">residue from photolysis (using the 325nm, 650nm, and 6200K lamps) of the Martian and Earth regolith showed </span><span dir="ltr" role="presentation">trace amounts of simple amino acids. However, due to a lack of sample work-up procedures, including deriviti</span><span dir="ltr" role="presentation">zation, the results were ultimately inconclusive. Method development and validation of the sample preparation </span><span dir="ltr" role="presentation">and analysis will be presented, and is under development to be active in autumn 2022. From the initial screening </span><span dir="ltr" role="presentation">experiments, it is hypothesized however, that by irradiating the Europan salt/soil analogues within an aqueous </span><span dir="ltr" role="presentation">solution, trace amounts of simple amino acids are postulated to form in the resulting residue.</span> <span dir="ltr" role="presentation">This is as a </span><span dir="ltr" role="presentation">consequence of using the same ISM relevant molecule and chemical similarities between the Martian regolith </span><span dir="ltr" role="presentation">and what is postulated to be in Europa’s soil/oceans. The implications for Europa to previously, currently, or </span><span dir="ltr" role="presentation">subsequently, harbour life will be discussed. Further details and results will be presented at the meeting.</span></div> </div> <div class="page" role="region" data-page-number="2" aria-label="Page 2" data-loaded="true"> <div class="canvasWrapper"> </div> <div class="textLayer"><strong><span dir="ltr" role="presentation">References</span></strong><br role="presentation" /><span dir="ltr" role="presentation">[1] Pascale Ehrenfreund and Karl M. Menten.</span> <span dir="ltr" role="presentation">From Molecular Clouds to the Origin of Life</span><span dir="ltr" role="presentation">, pages 7–23. Springer</span><br role="presentation" /><span dir="ltr" role="presentation">Berlin Heidelberg, Berlin, Heidelberg, 2002.</span><br role="presentation" /><span dir="ltr" role="presentation">[2] Norio Kitadai and Shigenori Maruyama. Origins of building blocks of life: A review.</span> <span dir="ltr" role="presentation">Geoscience Frontiers</span><span dir="ltr" role="presentation">,</span><br role="presentation" /><span dir="ltr" role="presentation">9(4):1117–1153, 2018.</span><br role="presentation" /><span dir="ltr" role="presentation">[3] Jere H. Lipps and Sarah Rieboldt. Habitats and taphonomy of europa.</span> <span dir="ltr" role="presentation">Icarus</span><span dir="ltr" role="presentation">, 177(2):515–527, 2005. Europa</span><br role="presentation" /><span dir="ltr" role="presentation">Icy Shell.</span></div> </div>