GLOBULES like those found in a meteorite that fell on the frozen Tagish Lake in north-western Canada may have helped life on Earth get started.
The meteorite, which landed in 2000, is of a type called a carbonaceous chondrite. In 2002, researchers found hydrocarbon bubbles, or globules, in pieces of the meteorite. An analysis of isotopes of hydrogen and nitrogen by a team led by Keiko Nakamura-Messenger of NASA鈥檚 Johnson Space Center in Houston, Texas, has now shown that the globules formed in temperatures of about 10 to 20 kelvin, which would have existed in the outer reaches of the developing solar system (Science, vol 314, p 1439). The globules are extremely old, says team member Scott Messenger. 鈥淲e鈥檙e looking at the original structures of organic objects that formed long before the Earth.鈥�
The presence of structures that could separate an organism鈥檚 internal chemistry from its environment is thought by some to have been a crucial step in the evolution of life. A chondrite鈥檚 globules could have provided the necessary raw materials and membrane-like barriers.
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