According to a study published in the journal Science, researchers at Imperial College of Technology found that the volatile chemical substances on the earth may have a distant origin, some of which constitute the cornerstone of life, by examining 18 meteorites from different sources. The study found that about half of the volatile element zinc on the earth comes from asteroids outside the solar system, including Jupiter, Saturn and Uranus. Volatiles are elements or compounds that change from solid or liquid to vapor at relatively low temperatures. They include the six most common elements found in organisms and water. Therefore, the increase of this material is very important for the emergence of life on Earth. Previous studies have shown that the earth is almost completely formed by the materials of the inner solar system, and the researchers infer that these materials are the main source of volatile chemical substances on the earth. In contrast, the new discovery suggests that the outer solar system has played a greater role than previously thought. According to the data from Imperial College London, about half of the zinc on the earth is transported by materials from the outer solar system outside the orbit of Jupiter. Researchers said that extrasolar system substances played a crucial role in the establishment of volatile chemicals on the earth. Without their contribution, the volatile content of the earth would be much lower than that known today, and would be drier, leading to the inability to nourish and sustain life. In the study, the team examined 18 meteorites from different sources, of which 11 were from the inner solar system, called non-carbonaceous meteorites, and 7 were from the outer solar system, called carbonaceous meteorites. For each meteorite, they measured the relative abundance of five different forms (or isotopes) of zinc, and then compared each isotope fingerprint with the earth sample to estimate the contribution of each material to the earth's zinc. The results show that although the earth only absorbs about 10% of the mass from the carbonaceous body, this material provides about half of the zinc on the earth. Next, researchers will analyze the rocks of Mars and the moon. It is generally believed that the moon was formed when a huge asteroid hit the embryonic earth about 4.5 billion years ago, and the analysis of zinc isotopes in lunar rocks will help to test this hypothesis. [Editor in Chief Circle] Volatile chemicals are crucial to the origin of life on Earth. Previous research believed that the earth's material almost came from the solar system. This time, researchers examined 18 meteorites from different sources, and the results were somewhat surprising: about half of the zinc inventory on the earth was provided by materials from the outer solar system. The origin of water on the earth may also be related to volatile substances transported from outside. Without these outsiders, the earth might be dead and unable to breed life. The researchers have planned the next research direction, aiming at Mars and the moon, and also analyzing zinc isotopes to test the hypothesis of the origin of the moon. (Xinhua News Agency)