Nature Geosci. doi:10.1038/ngeo941 (2010)

The Solar System just got a little older. New information from a chondritic meteorite — a rocky artefact from the Solar System's earliest days — puts the age of the Solar System at about 4.5682 billion years, between 0.3 million and 1.9 million years older than previous estimates.

Audrey Bouvier and Meenakshi Wadhwa of Arizona State University in Tempe determined this age after measuring the ratios of different lead and magnesium isotopes inside the ancient rock. This also allowed them to estimate the initial abundance of an iron isotope often found in such meteorites. Because this iron probably formed within an ageing giant star, which then exploded as a supernova, the finding gives credence to the theory that a nearby supernova helped to trigger the formation of our Solar System.