A detailed study of two meteorites that impacted our planet in 1998 shows that the space rocks are rich in hydrocarbons and amino acids – important ingredients for life. This finding, published in Science Advances, suggests that the ingredients for life are common across the solar system.
Within the meteorites, the researchers discovered tiny salt crystals. Inside those crystals, there were mixtures of water molecules and other compounds. While this is not proof that life exists elsewhere in the solar system, it does tell us that complex chemistry was already happening in the solar system a billion years before life developed on our planet.
“Everything leads to the conclusion that the origin of life is really possible elsewhere,” lead author Dr Queenie Chan, from The Open University, said in a statement. “There is a great range of organic compounds within these meteorites, including a very primitive type of organics that likely represent the early solar system’s organic composition.”
The data suggests that these two objects had been going around our solar system's asteroid belt and interacting with objects there like Ceres. Ceres is a dwarf planet like Pluto and the largest object in the belt. Scientists have found evidence of salts and water from the object already.
“This is really the first time we have found abundant organic matter also associated with liquid water that is really crucial to the origin of life and the origin of complex organic compounds in space,” Dr Chen explains.
Chen added: “We’re looking at the organic ingredients that can lead to the origin of life.”
The similarities of these two meteorites suggest there was an exchange of materials between their parent objects. Maybe a small asteroid impacted a larger one. One of the two objects, called Zag, contains organics produced on distinct parent bodies. However, a better understanding of how organic materials are spread via impacts is clearly needed.
“Things are not as simple as we thought they were,” Chan said.
The team used sophisticated X-ray analysis to measure which specific elements were present in the salt crystals. This technique was able to place the molecules with a precision in the tens of nanometers (billionth of a meter).
“We revealed that the organic matter was somewhat similar to that found in primitive meteorites, but contained more oxygen-bearing chemistry,” Yoko Kebukawa, an associate professor of engineering at Yokohama National University in Japan, said. “Combined with other evidence, the results support the idea that the organic matter originated from a water-rich, or previously water-rich parent body – an ocean world in the early solar system, possibly Ceres.”
The team would like to analyze more meteorites to see if there’s more variation in the organics from the early solar system.