Sunday, June 12, 2011
Tagish Lake space rock holds seeds of life
B.C. meteorite suggests life on Earth came from space
Vancouver Sun: The space rock first made headlines in 2000, when it streaked across the northern skies and crashed to Earth along the B.C.-Yukon border... Now the rock is in the spotlight again, providing what scientists say are important new clues about the building blocks of life and how they formed in the early universe more than 4.6 billion years ago.
'What we are seeing are the ingredients of life,' said planetary geologist Christopher Herd at the University of Alberta. Herd and a team from NASA and several U.S. universities report in the journal Science that they have found several types of organic molecules of 'prebiotic importance' in fragments of the meteorite. And they say some of them were likely shaped by processes on their home asteroid billions of years ago.
This indicates that there may have been a 'Goldilocks window' when organic molecules formed on asteroids and may have seeded Earth and other newly formed planets with the chemical precursors for life to emerge...
The Tagish Lake meteorite is described as the most pristine ever recovered... Most meteorites that fall to Earth are made of nickel or iron. The Tagish Lake space rock is the much rarer carbonaceous chondite variety... The analysis turned up a dozen different amino acids, which are used to build proteins and other molecules common in cell walls... One also appears to contain evidence of amino acid synthesis on the asteroid. Herd said the best explanation he and his colleagues can come up with is that organic material was altered in parts of the asteroid by percolating water.
Image source here.