Chemistry olympiad dating moon rock
The problem becomes intricate if more than one event that affected the radiogenic isotope systems has occurred during the evolution of the rock.
Many rocks have complex histories, and the challenge in isotopic age determination is to unravel and date not one, but each of the events that affected their evolution.] To date, only terrestrial, lunar, and meteoritic samples have been dated by isotopic methods.
Much work remains to be done, however, to refine the accuracy of these age estimates based on crater densities.
More extensive telescopic observations are needed to improve our knowledge of the physical properties and collision rates of the planet-crossing bodies, and computer models must be refined to estimate [Another method that has been used successfully on the Moon to estimate absolute ages involves the correlation of the morphology of small craters (1 km in diameter) with the absolute age of a surface determined from isotopic measurements (Shoemaker, 1966).
The technique depends on an erosion model that relates the shape of a crater to the integrated flux of meteoroids and secondary debris that have impacted the surface since the crater was fresh.
It has also been demonstrated that the flux of comets in the neighborhood of the terrestrial planets is closely linked to their flux in the neighborhood of Jupiter (Shoemaker and Helin, 1977).
The isotopic method of determining absolute age is the most accurate and desirable way of dating planetary surfaces, but collecting and returning rock samples from distant planets and satellites is a difficult and expensive endeavor.
Furthermore, some surfaces, such as those of the icy satellites of Jupiter and Saturn, may not yield rocks that are datable by current isotopic techniques.
If the rate at which craters are formed is known, then it is possible to estimate the absolute age of the surface.
The present rate of crater formation can be estimated from telescopic observations of various planet-crossing objects.