Free Astronomy Magazine November-December 2023

15 NOVEMBER-DECEMBER 2023 ASTRO PUBLISHING T his conceptual image illustrates the types of organic molecules found in the sample of asteroid Ryugu collected by Japan’s Hayabusa 2 spacecraft. Organ- ics are the building blocks of all known forms of terrestrial life and consist of a wide variety of compounds made of carbon combined with hydrogen, oxygen, nitrogen, sulfur, and other atoms. However, organic molecules can also be cre- ated by non-living processes, such as chemical reactions in asteroids. [NASA/JAXA/Dan Gallagher] amino and nucleic acids that allows these molecules to form more com- plex structures like proteins, ribo- somes, cell membranes, and various other cellular components. At the timescales of chemical reactions, these carbon bonds not only pro- vide molecules all the time in the world to undergo transformations into different and larger molecules, but they provide molecules all the time on many worlds to undergo these same processes. We know this from the detection of vital amino acids in space. Two biological rele- vant amino acids – glycine and L- alanine – were among at least eight other abiotic amino acids returned to Earth during Japan’s Hayabusa 2 mission to the asteroid Ryugu in 2020. The evidence for the complex amino acid tryptophan in the Perseus Molecular Cloud has been recently presented by Dr. Susana Iglesias-Groth based on data from the Spitzer Space Telescope. A very recent IRAM/Yebes Observatory study by Sans-Novo et al. even re- ports the detection of carbonic acid, the chemical backbone of amino acids and a basis for the formation of all of the amino acids, in the Milky Way. The highly reactive CH 3 + is one small but important organic fragment that facilitates the chem- istry that ultimately leads to these larger organics being possible. While it is possible that the chem- istry for life on Earth happened in its entirety on its surface or deep in our ancient oceans, these and other detections of organics in space hint that this foundational chemistry could have begun during or well before the formation of our own Solar System, and the delivery of these organics to Earth accelerated the earliest processes in the devel- opment of what became unicellular life. The detection of PAHs hint at the quantity and variety of large molecules that can form over vast periods of time, while the presence of CH 3 + reveals what any sunbather already knows – stellar radiation is a driver of chemistry by making sta- ble molecules reactive, giving them the energy to drive even more chemistry. !