Distinguishing between terrestrial and extraterrestrial organic compounds in the CM2 Aguas Zarcas carbonaceous chondrite: Implications for intrinsic organic matter

Abstract

Soluble organic matter analyses of astromaterials can provide valuable information on the chemistry of our solar system and the processes that occur within it. The surface of the Earth, however, is a significant source of organic compounds due to the presence of life; this environment represents a major source of potential contamination for recently fallen meteorites. Here, we analyze select stones of the CM2 Aguas Zarcas carbonaceous chondrite,

Organic compounds in the Tarda C2 ungrouped carbonaceous chondrite: Evaluating the sources of contamination in a desert fall

“…Although S 8 is used in pharmaceuticals, these are absent from the Tarda sand. Furthermore, they are unlikely to be found with the suite of contaminating compounds from the environment, while they are commonly found intrinsic to other carbonaceous chondrites like Tagish Lake and Aguas Zarcas (Hilts et al., 2014; Tunney, Hill, et al., 2020). The compounds found in common between the sand sample and the Tarda specimens are typically used in fuels and plasticizers.…”

“…The remaining compounds potentially originate from agricultural products, fuels, pesticides, pharmaceuticals, and plasticizers. These compound types are commonly found as terrestrial surface contaminants on meteorites (Tunney, Herd, et al., 2020) and therefore do not have an extraterrestrial source and are not laboratory contaminants. The low total number of compounds detected in Tarda A compared to Tarda B and the sand sample is likely due to a lack of contamination of that particular stone at its fall location and during subsequent handling.…”

Multiscale correlated analysis of the Aguas Zarcas CM chondrite

“…They have described abundant phyllosilicate (mainly serpentine) mixed with olivine and pyroxene grains and FeNi sulfides. Some groups have also shown that the organic matter contained in AZ is also intriguing (Pizzarello et al, 2020; Tunney et al, 2020). According to Kebukawa et al (2020), the organic compounds present inside the metal‐rich lithologies are unique with high aliphatic concentrations, indicating a more primitive nature relative to the organic matter found in a “typical” CM lithology.…”

“…This chondrite is classified as a CM2 breccia in the Meteoritical Bulletin (Gattacceca et al, 2019). In 2020, several groups presented the results of preliminary characterizations and analyses of several fragments of AZ (Davidson et al, 2020;Hicks & Bridges, 2020;Kebukawa et al, 2020;Kouvatsis & Cartwright, 2020;Pizzarello et al, 2020;Takir et al, 2020;Tunney et al, 2020;Villalon et al, 2020) describing at least three main lithologies: one rich in metal and two CM lithologies, including a chondrulerich and a chondrule-poor variety.…”

Testing materials to mitigate terrestrial organic contamination of meteorites: Implications for collection, curation, and handling of astromaterials

“…), to enable later characterization of the contaminants present in the surrounding environment and help inform sources of contaminants on the meteorite. For example, the collection of sand from the Tarda fall area was key to discriminating terrestrial contamination (Tunney, Hill, Herd, Hilts, et al., 2022). If the strewn field falls within an agricultural area, it would be useful to know what agricultural products are used on surrounding plots of land due to the long‐range transport of contaminants (Tunney et al., 2020).…”