Editor's Summary

25 August 2005

Angrites: early arrivals

The latest ultra-precise measurement techniques have been used to obtain lead isotope ages for two examples of a rare type of meteorite, called basaltic angrites. These 'differentiated' meteorites are from parent bodies that were once molten and had solidified as a metal core and silicate mantle. Their absolute age is about 4.6 billion years, only a million years younger than the currently accepted minimum age of the Solar System. An excess of magnesium-26 in the angrite samples suggests that aluminium-26 decay triggered melting of the planetesimal that was the parent body.

LetterEarly planetesimal melting from an age of 4.5662 Gyr for differentiated meteorites

Joel Baker, Martin Bizzarro, Nadine Wittig, James Connelly and Henning Haack


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