Dating the moon-forming impact event with meteorites. Date: April 16,, Source: University of Arizona; Summary: Through a combination of data analysis. Dating the moon-forming impact event with meteorites. Date: April 16,, Source: University of Arizona; Summary: Through a combination of data analysis. Many of your questions are answered in this question and associated answers: Why is Earth's age given by dating meteorites rather than its.
The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of million to more than billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to meteorite dating the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.
Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead to lead changes over time owing to the decay of radioactive uranium and uraniumrespectively.
Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.