Nat Astron, published online Janudoi: 10.Ever since scientists started looking at meteorites with microscopes, they’ve been puzzled-and fascinated-by what’s inside. Evidence of presolar SiC in the Allende Curious Marie calcium-aluminium-rich inclusion. The results were published in the journal Nature Astronomy. “This finding forces us to revise how we see the conditions in the early Solar Nebula.” “Not only do we see silicon carbide in the fine-grained CAIs, we see a population of small grains that formed at special conditions.” “It was beautiful when all noble gases pointed to the same source of the anomalies - silicon carbide,” Dr. Pravdivtseva’s team the first to find it. Other scientists have looked for evidence of silicon carbide in such CAIs in meteorites using noble gases before, but Dr. For me, it is like solving a mystery,” Dr. And then we had a puzzle of noble gas isotopic signatures to untangle. They heated it up incrementally, increasing temperature and measuring the composition of four different noble gases released at each of 17 temperature steps. The scientists had 20 mg of Curious Marie to work with, which is a relatively large sample from a cosmochemistry perspective. “Many refractory inclusions were melted and lost all textural evidence of their condensation. “The fact that silicon carbide was not completely destroyed in Curious Marie can help us to understand this environment a little bit better.” “The fact that silicon carbide is present in refractory inclusions tells us about the environment in the Solar Nebula at the condensation of the first solid materials,” Dr. That’s important because presolar grains are generally thought to be too fragile to have endured the high-temperature conditions that existed near the birth of our Sun.īut not all CAIs were formed in quite the same way. Pravdivtseva and colleagues used noble gas isotopic signatures to show that presolar grains of silicon carbide are present in Curious Marie. This fragment of the Allende meteorite and curium are named after the Nobel Prize-winning physicist and chemist Marie Curie, whose pioneering work laid the foundation of the theory of radioactivity. In 2016, a research team from the University of Chicago discovered evidence in Curious Marie that a rare element called curium was present during the formation of the Solar System. Olga Pravdivtseva, a researcher in the Physics Department and the McDonnell Center for the Space Sciences at Washington University, Saint Louis. Following our current understanding of solar system formation, presolar grains could not survive in the environment where these inclusions are formed,” said Dr. “What is surprising is the fact that presolar grains are present. These objects, some of the first to have condensed in the Solar Nebula, help cosmochemists define the age of the Solar System. ![]() Image credit: The Planetary Society.Ĭurious Marie is a notable example of an inclusion, or a chunk within a meteorite, called a calcium-aluminum-rich inclusion (CAI). The white, fuzzy-looking features in this fragment are calcium-aluminum-rich inclusions - some of the first solids to condense in the Solar System. Curious Marie is a sample of the Allende meteorite, which fell in northern Mexico in February 1969.
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