Cometary micrometeorites and input of prebiotic compounds

• Published in: BIO Web of Conferences
• Main Author: Engrand C.
• Format: Article in Journal/Newspaper
• Language: English; French
• Published: EDP Sciences 2014
• Subjects: Microbiology; QR1-502; Physiology; QP1-981; Zoology; QL1-991; Antarctic; Antarc*
• Online Access: https://doi.org/10.1051/bioconf/20140203003; https://doaj.org/article/e81a454b755349958e8905b0f52a06dd

The apparition of life on the early Earth was probably favored by inputs of extraterrestrial matter brought by carbonaceous chondrite-like objects or cometary material. Interplanetary dust collected nowadays on Earth is related to carbonaceous chondrites and to cometary material. They contain in particular at least a few percent of organic matter, organic compounds (amino-acids, PAHs,…), hydrous silicates, and could have largely contributed to the budget of prebiotic matter on Earth, about 4 Ga ago. A new population of cometary dust was recently discovered in the Concordia Antarctic micrometeorite collection. These “Ultracarbonaceous Antarctic Micrometeorites” (UCAMMs) are dominated by deuterium-rich and nitrogen-rich organic matter. They seem related to the “CHON” grains identified in the comet Halley in 1986. Although rare in the micrometeorites flux (<5% of the micrometeorites), UCAMMs could have significantly contributed to the input of prebiotic matter. Their content in soluble organic matter is currently under study.