Nature News | 22 Aug 2010
The age of the Solar System redefined by the oldest Pb–Pb age of a meteoritic inclusion A Bouvier, M WadhwaMeteorite dating resets solar clock.
A meteorite found in the Sahara Desert has helped to pin down the age of the Solar System and shed light on how it may have formed.
The new estimate, which comes from measuring the ratios of lead isotopes inside the chondrite — an ancient stony meteorite — suggests that the Solar System is 4.568 billion years old. This is 0.3–1.9 million years older than some previous studies projected. The relatively small revision means that models of the gas and dust that gave rise to the Solar System should have around double the amount of a certain iron isotope, iron-60, than previously suggested.
This high quantity of iron can be traced back to the bellies of massive, short-lived stars, one of the only places in the universe where iron is produced. When these stars explode as supernovae at the end of their lives, they would have seeded the ancient Solar System.
"This suggests that one or more supernovae happened before the Sun's formation, explaining all these elements and their respective abundances," says Audrey Bouvier from [Arizona State University] in Tempe, lead author of the study, published online in Nature Geoscience today
- Nature Geoscience (online 22 Aug 2010) DOI: 10.1038/NGEO941