Among the biogenic elements (C, H, O, N, P, S), phosphorus significantly ranks higher in its relative abundance for biological systems compared to other environments (c.f., 6th most abundant in life versus the 18th most abundant in the universe). This suggests that phosphorus could be the limiting ingredient for life, and phosphorus-containing organic compounds may have use as biomarkers. During the ROSETTA mission, P+ was observed in the coma of comet 67P/Churyumov-Gerasimenko, and the potential source of this P+ is still being debated. Rivilla et al. (2019) have suggested that the P+ may be a fragment from PO. Schreibersite (Fe,Ni)3P is one of the first P-containing minerals to condense during planetary cooling and one of the primary P-containing minerals in iron and stony-iron meteorites. Therefore, it is a likely P-bearing mineral in cometary cores. This project will attempt to observe the formation of small P-containing molecules when ice-covered synthetic schreibersite is irradiated with electrons of varying energies (10-1000 eV). The relative abundance of the most likely parent molecules of P+, including PO, PN, CP, HCP, and PH3 will be measured using surface sensitive IR spectroscopy and mass spectrometry under conditions mimicking comets (i.e., temperatures below 150 K and ultrahigh vacuum pressure). Preliminary results will be shared. Our measurements will help constrain the conditions under which volatile phosphorus species are formed in the outer Solar System. Additionally, they may impact our understanding of the phosphorus chemical cycle on icy planetary bodies (e.g., comets, Jovian and Saturnian moons) and the potential habitability of planets elsewhere.

This document is currently not available here.