Dr Antonin Knizek: Publications

Formamide-Based Post-impact Thermal Prebiotic Synthesis in Simulated Craters: Intermediates, Products and Mechanism

Frontiers in Astronomy and Space Sciences Frontiers Media SA 9 (2022) 882145

Authors:

Martin Ferus, Antonín Knížek, Lukáš Petera, Adam Pastorek, Jana Hrnčířová, Luboš Jankovič, Ondřej Ivanek, Jiří Šponer, Anna Křivková, Homa Saeidfirozeh, Svatopluk Civiš, Elias Chatzitheodoridis, Klaudia Mráziková, Lukáš Nejdl, Franz Saija, Judit E Šponer, Giuseppe Cassone

Abstract:

Influx of matter from impacting meteoroids and hydrothermal crater weathering are important factors modifying the rock and mineral inventory of young planets undergoing heavy bombardment. These processes may have influenced not only the geochemical environment of, e.g., early Mars and other planets, but also the peculiar prebiotic chemistry on early Earth. Here, we present a synergistic experimental and computational investigation of the intermediates of chemical reactions of the formamide-based synthesis of canonical and non-canonical nucleobases by thermochemistry in hot hydrothermal crater environments. We put our findings into context with previously investigated plasma-initiated synthesis occuring directly during impact. Both processes result into the formation of all canonical nucleobases, hypoxanthine, purine, and into the onset of the simplest amino acid glycine. Furthermore, it turns out that radical species such as CN and H play a key role in the plasma-assisted impact chemistry. However, post-impact thermochemistry is essential for the origin of formamidine and 2-aminoacetonitrile, intermediate species detected in this study by means of FTIR spectroscopy.

Morphology of Meteorite Surfaces Ablated by High-Power Lasers: Review and Applications

Applied Sciences MDPI AG 12:10 (2022) 4869-4869

Authors:

Anna Křivková, Vojtěch Laitl, Elias Chatzitheodoridis, Lukáš Petera, Petr Kubelík, Antonín Knížek, Homa Saeidfirozeh, Barbora Drtinová, Václav Čuba, Dan Páclík, Tomáš Mocek, Jan Brajer, Jan Kaufman, Martin Divoký, Jakub Koukal, Roman Dudžák, Nikola Schmidt, Petr Boháček, Svatopluk Civiš, Libor Lenža, Miroslav Krůs, Martin Ferus

Abstract:

Under controlled laboratory conditions, lasers represent a source of energy with well-defined parameters suitable for mimicking phenomena such as ablation, disintegration, and plasma formation processes that take place during the hypervelocity atmospheric entry of meteoroids. Furthermore, lasers have also been proposed for employment in future space exploration and planetary defense in a wide range of potential applications. This highlights the importance of an experimental investigation of lasers’ interaction with real samples of interplanetary matter: meteorite specimens. We summarize the results of numerous meteorite laser ablation experiments performed by several laser sources—a femtosecond Ti:Sapphire laser, the multislab ceramic Yb:YAG Bivoj laser, and the iodine laser known as PALS (Prague Asterix Laser System). The differences in the ablation spots’ morphology and their dependence on the laser parameters are examined via optical microscopy, scanning electron microscopy, and profilometry in the context of the meteorite properties and the physical characteristics of laser-induced plasma.

Ariel – a window to the origin of life on early earth?

Experimental Astronomy Springer Science and Business Media LLC 53:2 (2022) 679-728

Authors:

Martin Ferus, Vojtěch Adam, Giuseppe Cassone, Svatopluk Civiš, Václav Čuba, Elias Chatzitheodoridis, Barbora Drtinová, Bertrand LeFloch, Alan Heays, Sohan Jheeta, Ákos Kereszturi, Antonín Knížek, Miroslav Krůs, Petr Kubelík, Helmut Lammer, Libor Lenža, Lukáš Nejdl, Adam Pastorek, Lukáš Petera, Paul Rimmer, Raffaele Saladino, Franz Saija, Laurenz Sproß, Jiří Šponer, Judit Šponer, Zoe Todd, Markéta Vaculovičová, Kristýna Zemánková, Vladislav Chernov

Nitrogen Oxide Production in Laser‐Induced Breakdown Simulating Impacts on the Hadean Atmosphere

Journal of Geophysical Research: Planets American Geophysical Union (AGU) 127:3 (2022) e2021JE006842

Authors:

Alan N Heays, Tereza Kaiserová, Paul B Rimmer, Antonín Knížek, Lukáš Petera, Svatopluk Civiš, Libor Juha, Roman Dudžák, Miroslav Krůs, Manuel Scherf, Helmut Lammer, Robert Pascal, Martin Ferus

Abstract:

AbstractThe high‐energy‐density synthesis of NxOy species is simulated in gas mixtures representing an O2‐free early‐Earth atmosphere by terawatt‐kilojoule‐class laser‐induced dielectric breakdown (LIDB). These experiments differ from previous LIDB experiments due to the 100 times greater energy delivered per pulse and sensitive analysis of products by high‐resolution infrared spectroscopy. The measured yields of NO, N2O, and NO2 are 0.08–8 × 1015, 5 × 1012, and 0.03–7 × 1014″��Ǳ�� J −1. The high N2O yield is above the upper‐limit constraint of previous tabletop LIDB experiments and the expected yield of a thermochemical freeze‐out at any temperature between 2000 and 5000 K, while the NO and NO2 yields are in broad agreement with freeze‐out models. Using a one dimensional chemical model of the Hadean atmosphere and a simple model of late bombardment, we compute the source flux of N2O assuming the same high production yield as measured experimentally and find the steady‐state partial pressure of N2O is insufficient to warm the climate.

The spectrum of ammonia near 0.793 μm

Journal of Quantitative Spectroscopy and Radiative Transfer Elsevier BV 273 (2021) 107838

Authors:

NF Zobov, T Bertin, J Vander Auwera, S Civiš, A Knížek, M Ferus, Roman I Ovsyannikov, Vladimir Yu Makhnev, Jonathan Tennyson, Oleg L Polyansky

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