The oldest solids formed in the solar system are calcium-aluminum-rich inclusions (CAIs), later small metal droplets contained in meteorites. The age of the CAI is considered to be the age of the Solar System, although the exact moment in which they correspond to the arrangement of the stars is unclear.
New research by a group of scientists at the Lawrence Livermore National Laboratory (LLNL) – looking at isotopes of the element molybdenum found on meteorites – suggests that our sun and solar system formed in a short period of 200,000 years.
By observing other stellar systems formed similar to ours, astronomers believe that it took about 1-2 million years for the cloud to break and the star to start. This is the first study to provide numbers on our solar system.
LLNL cosmochemist Greg Breneneka, lead author of the paper, said, “This work shows that this collapse, which led to the formation of the solar system, occurred very quickly in less than 200,000 years. If we scale all this into human lifespan, the structure of the solar system can be compared to a pregnancy lasting about 12 hours instead of nine months. This was a quick process. ”
The micrometer-to-centimeter-sized CAI is contained in a high-temperature atmosphere (more than 1,300 Kelvin), perhaps closer to the young sun. They were then transported externally to the area where carbonaceous condensate meteorites (and their parental bodies) formed, where they are found today. The majority of CAIs were formed about 40,000 to 200,000 years ago, 4.567 billion years ago.
In this study, scientists measured the molybdenum (mo) isotopic and trace element compositions of various CAIs taken from carbonaceous chondrite meteors, including the largest carbonaceous chondrite allende found on Earth. Because they found that CAI-specific mo isotopic compositions cover a whole range of materials prepared in a protoplanetary disk rather than just a small fragment, this inclusion would probably be in the shape of a cloud breakdown period.
Since the observed period of stellar origin (1-2 million years) was much longer than the formation of CAIs, the team was able to direct that the formation of CAIs marked an astronomical phase in the formation of the solar system, and ultimately, how fast the material made the solar system acceptable.
Journal Reference:
- Gregory A. Brannick et al. Astronomical reference to the formation of the solar system from molybdenum isotopes in meteorite inclusion science (2020). DOI: 10.1126 / Science.Az 84828282૨
