Ian Sample in The Guardian:
As lumps of rock go it looks much like any other, unexceptional despite the deep red of its cool, smooth surface. The pieces range in size from pea-sized lumps to larger fist-sized chunks. But today, scientists will announce this is no ordinary stone. Prised from a frozen lake in northern Canada, it has become a prime candidate for the oldest known object on Earth.
The chunk came from a meteorite that scored an arc of fire across the skies before slamming into Lake Tagish in British Columbia in 2000. It has been pored over by scientists ever since, and is today revealed to contain particles that predate the birth of our nearest star, the sun.
The Tagish Lake meteorite was already regarded as exceptional because its mineral composition linked it to the earliest days of the formation of the solar system, more than 4.5bn years ago. The fragments of meteorite that still exist are among the most pristine in the world, as they were protected from contamination when they became wedged in blocks of lake ice.
More here.