Nitrogen in the Earth’s atmosphere and in primitive meteorites (meteorites which have altered very little since their formation) may have been incorporated from a primordial icy reservoir in the early Solar System, according to a study published online in Nature Geoscience. Nitrogen-containing organic compounds that formed in the early Solar System, such as amino acids, may have contributed to the emergence of life on Earth.

Dennis Harries and colleagues analysed primitive meteorites and identified a nitrogen-bearing mineral called carlsbergite. The occurrence of carlsbergite is consistent with the reaction of metal in the emerging inner Solar System with hot and reactive ammonia. They propose that the ammonia was hosted in ices that were delivered to the inner Solar System and then heated by passing shock waves.

They also find that the nitrogen in the carlsbergite is geochemically similar to that found in the Earth’s atmosphere, suggesting that primordial ices may have also supplied nitrogen - and potentially nitrogen-bearing organic compounds - to the early Earth. The origin of the primordial ices, however, remains unknown.