This technique uses krypton, an odorless, colorless gas present in trace amounts in the Earth's atmosphere.Researchers tested this method on a 120,000-year-old sample of Antarctic ice."The atom trap is so sensitive that it can capture and count individual atoms," said Dr.Buizert "The only problem is that there isn't a lot of Krypton in the air, and thus there isn't much in the ice, either.
The ice samples were extracted using the Blue Ice Drill, which Brook describes as "a fairly simple but elegant device" designed to obtain "large ice cores (10 inches in diameter) from “blue ice,” which is shorthand for solid ice exposed at the surface of glaciers or ice caps," he adds.But there are significant differences between the two.Carbon dating works for objects that are up to about 50,000 years old.After the second half-life has elapsed, yet another 50% of the remaining parent isotope will decay into daughter isotopes, and so on.For all practical purposes, the original isotope is considered extinct after 6 half-life intervals. A small portion of a meteorite is vaporized in the device forming ions."Near the end you imply that low petrologic type chondrites are the most easily dated.Actually, meteorites that formed by melting, e.g., the various types of achondrites, usually give more precise ages.But "[i]t is unlikely that 81Kr dating will work in young (less than say 50,000 year) ice because of this long half life, whereas if we could get around the problem of 14C produced in ice we could use it to date ice in that younger range," Dr. Until 2011, before the new atom counter, named Atom Trap Trace Analysis, or ATTA, was developed, it was difficult to determine the age of ice using this method because Krypton-81 atoms are so few that it is difficult to count them.But with the ATTA, researchers can now capture and count individual atoms.Krypton, by contrast, is an inert gas that makes it more stable.It doesn't interact chemically and has a half-life of around 230,000 years, said Christo Buizert, a postdoctoral researcher at Oregon State University and lead author of the study.