The study of the isotopic composition of meteorites showed that material from the outer Solar system was an important source of the formation of the Earth’s atmosphere.
Planetary scientists from the University of St. Andrews studied the isotopic composition of zinc in meteorites formed in the inner and outer parts of the Solar System. The results show that a significant part of the volatile substances of the Earth’s atmosphere was formed far from our planet and was brought in by space objects.
In their work published in the journal Icarus, the authors studied the isotopic composition of zinc in carbon chondrites — the most common type of meteorites that formed in various parts of the Solar System. The study showed significant differences in the varieties of atoms of chemical elements of objects. At the same time, the composition of zinc isotopes on Earth is an intermediate variant between meteorites formed inside and outside the Asteroid Belt.
The results of the study show that from 5 to 6% of the Earth’s mass is made up of materials formed in the outer region of the Solar System — part of our planetary system, in which gas giants are located.
Scientists note that although only a small part of the total mass of the Earth came from the outer Solar system, this material must be enriched with volatile substances. For example, the analysis of zinc isotopes shows that at least 30% of this volatile substance is extraneous. Planetary scientists believe that for more volatile elements than zinc, the proportion will be even greater.
The question of the origin of volatile elements present on Earth is of fundamental importance for understanding the evolution of our planet. These elements are crucial for the emergence of life. The data from this study will help scientists understand how planets form and where to look for other habitable worlds.