Antartic radioactive dating of meteorites datingon com
Most rocks on Earth have melted time and again and thus are useless for figuring out how old the Earth is.Simple enough, see the meteorites formed alongside the planet, however, since the planet was pretty much a molten soup you can't date it properly, because we can only date it after it cooled down.Thus, although "extinct", these nuclides are present in meteorites, but produced by a more recent process."The idea that Rb-Sr is the most used chronometer for meteorites is largely based on work done 10-30 years ago.Obviously there are complexities, but there are not critical for this answer.Short answer: because the meteorites formed together with the Earth and the rest of the Solar System.Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.Visit Stack Exchange Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences. Sign up to join this community Some background: We are able to determine the age of certain rocks and minerals using measurements of radioactive and radiogenic isotopes of certain elements. Simply put, the resulting date is the time that has passed from the crystallisation of that mineral.
Actually, meteorites that formed by melting, e.g., the various types of achondrites, usually give more precise ages.Simply counting the number of rings will give one a fairly good idea of the age of the tree.Periods of heavy rain and lots of sunshine will make larger gaps of growth in the rings, while periods of drought might make it difficult to count individual rings. When a given quantity of an isotope is created (in a supernovae, for example), after the half-life has expired, 50% of the parent isotope will have decomposed into daughter isotopes.You say: You have to distinguish the time that the meteorites form and the time that they hit the Earth.If I throw a meteorite at you, and you date it, it still records the formation time and not the time that I threw it at you.