Contributed talk at FALCON 2005

Abstract

The emergence of RNA as a carrier of genetic information in the early stages of life depends not only on the presence of nucleobases but also on sugar molecules like ribose, which form the backbone of RNA strands. While ribose formation under early Earth conditions has been demonstrated, its potential synthesis in space environments—prior to planet formation—remains a key open question. This project investigates the formation of prebiotic sugars, in astrophysically relevant ice analogs processed under interstellar-like conditions.

We use a newly developed ultra-high vacuum (UHV) experimental setup that simulates the chemical evolution of cosmic ices subjected to energetic electron irradiation, mimicking the effect of cosmic rays. Ice mixtures composed of simple interstellar molecules (e.g., H₂O, CH₃OH, NH₃) are deposited on cold substrates mimicking cosmic dust grains (e.g., amorphous silicate and carbonaceous materials), and then irradiated with keV electrons from an electron gun. The resulting products are analyzed in situ using a combination of laser desorption ionization (LDI) and high-resolution Orbitrap mass spectrometry, allowing sensitive detection of complex organic molecules (COMs) without exposing the samples to air or damaging them during analysis.

Preliminary results from ex-situ analysis using gas chromatography have already identified several sugar-related compounds in the organic residues of electron-irradiated ice samples prepared in the UHV chamber, providing evidence that such molecules can form under astrophysical conditions in the new setup. These findings strengthen the hypothesis that essential RNA components may have been synthesized in space and delivered to early Earth via comets or meteorites. While this study focuses on sugars, it also lays critical groundwork for future efforts to explore the formation of more complex biomolecules such as nucleosides, linking sugars and nucleobases into proto-genetic structures.

Klaus Paschek

Postdoc - Astrophysics

My research interests include prebiotic synthesis, planetary science, and the origins of life.