The solution to the longstanding meteorite mystery is found in the violent event that likely preceded our solar system's formation.
The solar system's raw material was dispersed when a shock wave from an exploding supernova injected material into a cloud of dust and gas. After the event, most of the injected matter was drawn into the center of the whirlwind, where the intense build up of pressure allowed nuclear fusion to begin. The young star was surrounded by a disk of gas and dust from which the planets and other solar system bodies coalesced.
Studying the composition of meteorites can be used to test theories of solar system formation and evolution.
The elements with the same number of protons and neutrons are called isotopes. The number of neutrons in the nucleus can cause a radioactive isotope to be unstable. To gain stability, the isotope releases energetic particles, which alter its number of protons and neutrons, transmuting it into another element.
The amount of daughter products in meteorites can tell us when and how they formed.
The iron isotope with an atomic weight of 60 takes 2.6 million years for half of the atoms to decay, which is called the "half-life." The raw material from which the chondrite was constructed contained the remnants of a supernova explosion that occurred just a couple million years prior to its creation.
The supernova origin story can be confirmed using the chondrite record. The material from which they formed did not originate in a stellar explosion, because other, less-primitive, non-carbonaceous meteorites lack this iron 60 composition. Where did it originate?
Boss said there was no explanation for the change.
He was one of the originators of the supernova injection origin story and has been honing models of our solar system for several decades. Within a million years, the young sun will encounter a patch of material that is composed of iron-60 and other supernova-generated particles.
Boss said it was amazing to be able to link the model to the evidence. It ends the story with a bow.
More information: Alan P. Boss, Possible Implications of Relatively High Levels of Initial 60Fe in Iron Meteorites for the Noncarbonaceous–Carbonaceous Meteorite Dichotomy and Solar Nebula Formation, The Astrophysical Journal (2022). DOI: 10.3847/1538-4357/ac6609 Journal information: Astrophysical Journal
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