How Old is the Earth-Moon System

In this chapter we cover the Giant Impact Hypothesis as the starting point for the age of the modern Earth-Moon system. We’ll see a Fulldome illustration on what it might have looked like. We then cover Oxygen Fractionation and use water evaporation to show how it works. We build the Terrestrial Fractionation line and show that all oxygen on Earth falls on this line. We then show that meteors like Allende do not fit on the line, but Moon rocks do. We then begin our deeper dive into how we date rocks using Radiometric Dating with uranium and lead. We review the discovery of radiation with its alpha, beta and gamma rays. We cover half-life and the exponential law of radioactive decay including the uranium to lead decay chains. We also cover the Chemical Abrasion – Isotope Dilution – Thermal Ionization Mass Spectrometry (CA-ID-TIMS) method for dating zircon crystals in rocks found here on Earth. This includes a look at how the Memorial University of Newfoundland does it. We end with the age of the oldest Earth and Moon rocks.