Improving the dating of meteoritic carbonates

An improved method for the dating of meteoritic carbonate grains, which results in an age which is younger than previous estimates, is presented in Nature Communications this week. Carbonates in primitive meteorites form in asteroids and dating them tells us when hydrous asteroids formed. This new younger carbonate age suggests that the parent asteroid formed 3.5 million years after the birth of the Solar System. Wataru Fujiya and colleagues analysed several carbonate grains in four meteorites. The results for these carbonates converged on an age of 4563.4 million years ago, which is younger than previous estimates for these same meteorites. The authors interpret this to mean a late onset of aqueous activities in the Solar System.