A nuclear microprobe study of the distribution and concentration of carbon and nitrogen in Murchison and Tagish Lake meteorites, Antarctic micrometeorites, and IDPs: Implications for astrobiology

摘要

Using a nuclear microprobe, we measured the carbon and nitrogen concentrations and distributions in several interplanetary dust particles (IDPs) and Antarctic micrometeorites (MMs), and compared them to 2 carbonaceous chondrites: Tagish Lake and Murchison. We observed that IDPs are richest in both elements. All the MMs studied contain carbon, and all but the coarse-grained and 1 melted MM contained nitrogen. We also observed a correlation in the distribution of carbon and nitrogen, suggesting that they may be held in an organic material. The implications for astrobiology of these results are discussed, as small extraterrestrial particles could have contributed to the origin of life on Earth by delivering important quantities of these 2 bio-elements to the Earth's surface and their gas counterparts, CO_2 and N_2, to the early atmosphere.