Exploring the Prebiotic Chemistry of Europa

1 Abstract

Europa is one of the celestial bodies within our solar system that has the highest potential of harbouring life. In this poster, we will discuss a method which will be used to help determine the survivability of life on Europa and whether or not Europa has the appropriate chemistry necessary for life. Through subjecting regolith in aqueous solution to UV/Visible radiation, and adopting a ’systems chemistry’ approach, the yield of organic matter, more specifically amino acids, produced will be investigated to determine the prime conditions and chemicals required for life on Europa.

2 Introduction

As the ability to explore complexity and study planets and celestial bodies within our own solar system becomes more feasible, it is increasingly practical to address the age old question of whether life can, or cannot, exist outside of the Earth. With the forthcoming European Space Agency (ESA) JUpiter ICy moons Explorer (JUICE) mission, the focus on the viability of life has been shifted onto the icy moons of Jupiter. The moons of Jupiter (particularly Europa and Ganymede) have high potential for life and have become of particular interest for research in the fields of Astrochemistry and Astrobiology. Specifically for the moon Europa, the interest lies in whether the moon has the necessary chemistry for life to emerge, [3]. By performing a systematic study of how Europan regoliths/salts react with plausible molecules after being irradiated and subject to similar Europan conditions, the likelihood of life emerging on Europa can be quantified. With the potential discovery of organics on the surface and near sub surface it is increasingly urgent to determine the composition and routes to synthesis of these organics.

3 Method

Samples of formulated Europan soil or salt analogues will be added to an aqueous solution of water and a molecule that has been observed in the interstellar medium (ISM), [1]. With varying ratios of aqueous solution, mineral, and ISM relevant molecule, the samples are irradiated with UV/Visible light using a range of wavelengths (365nm, 425nm, 475-480nm, 650nm, and 6200K lamps) for periods of time ranging from 72 hours to 120 hours. A statistical experimental design approach will be employed. The resulting residue using both high-performance liquid chromatography mass spectrometry (LCMS) and gas chromatography mass spectrometry (GCMS). A ’targeted’ methodology will be employed for the analyses specifically to determine if the analyte contains amino acids, or any trace of amino acids, [2].

4 Results

An initial screening run of this experiment using Martian, Earth, and Moon regolith revealed that the resulting residue from photolysis (using the 325nm, 650nm, and 6200K lamps) of the Martian and Earth regolith showed trace amounts of simple amino acids. However, due to a lack of sample work-up procedures, including derivitization, the results were ultimately inconclusive. Method development and validation of the sample preparation and analysis will be presented, and is under development to be active in autumn 2022. From the initial screening experiments, it is hypothesized however, that by irradiating the Europan salt/soil analogues within an aqueous solution, trace amounts of simple amino acids are postulated to form in the resulting residue. This is as a consequence of using the same ISM relevant molecule and chemical similarities between the Martian regolith and what is postulated to be in Europa’s soil/oceans. The implications for Europa to previously, currently, or subsequently, harbour life will be discussed. Further details and results will be presented at the meeting.

 

References
[1] Pascale Ehrenfreund and Karl M. Menten. From Molecular Clouds to the Origin of Life, pages 7–23. Springer
Berlin Heidelberg, Berlin, Heidelberg, 2002.
[2] Norio Kitadai and Shigenori Maruyama. Origins of building blocks of life: A review. Geoscience Frontiers,
9(4):1117–1153, 2018.
[3] Jere H. Lipps and Sarah Rieboldt. Habitats and taphonomy of europa. Icarus, 177(2):515–527, 2005. Europa
Icy Shell.