A group of scientists from the Royal Ontario Museum working with researchers from McMaster University and York University are using what they call state-of-the-art techniques to map individual atoms in minerals formed in fluids on an asteroid over 4.5 billion years ago. The scientists are studying the Royal Ontario Museum’s Tagish meteorite using Atom-probe tomography. The technique can image atoms in 3D.
The team is targeting molecules along boundaries and pores between magnetite grains that likely formed on the asteroid’s crust. In those boundaries and pores, the team has discovered water precipitates left in the grain boundaries on which they conducted their groundbreaking research. Lead author Doctor Lee White says that the scientists know water was abundant in the early solar system, but little direct evidence of the chemistry or acidity of liquids remain.
White says that chemistry and acidity of those liquids would have been critical to the early formation and evolution of amino acids and, eventually, microbial life. The atomic-scale research is providing scientists with the first evidence of the sodium-rich and alkaline fluids in which the magnetite framboids formed. The fluid conditions are preferential for the synthesis of amino acids and open the door to microbial life formation as early as 4.5 billion years ago.
The researchers say that amino acids are essential building blocks of life on Earth, but we still have a lot to learn about how they formed in the solar system. The more the team learns about temperature and pH, the better they can understand the synthesis and evolution of molecules and what we know as biotic life on Earth.
The Tagish Lake carbonaceous chondrite was retrieved from an ice sheet in British Columbia’s Tagish Lake in 2000 and later acquired by the Royal Ontario Museum. The sample used by the team has never been above room temperature or exposed to liquid water, allowing scientists to link the measured fluids to the parent asteroid. Atom probe tomography allows the scientists to make discoveries on small amounts of material a thousand times thinner than a human hair.