Are we all aliens? Did the building blocks of our life on Earth, originate from space? According to a new study of molecules in a meteorite fragment, it would seem that way, as the material for DNA, RNA and genetic coding, can be found on this rock that landed on Earth from space.
A meteorite that exploded above Canada 11 years ago has provided strong evidence that life's building blocks came from space. Fragments of the rock that landed on Tagish Lake, British Columbia, yielded a mix of organic compounds. They included amino acids and monocarboxylic acids, both essential to the evolution of the first simple life forms on Earth. Analysis of the chemicals revealed information about their history on the asteroid from which the meteorite came, and lent weight to the theory that organic material originates in gas and dust clouds between the stars.
If the theory is right, the building blocks of life would have been spread throughout our developing solar system. They may, for example, also have provided a foothold for life on Mars. Lead researcher Dr Chris Herd, of the University of Alberta, said: 'The mix of pre-biotic molecules, so essential to jump-starting life, depended on what was happening out there in the asteroid belt. 'The geology of an asteroid has an influence on what molecules actually make it to the surface of the Earth.' The findings were published today in the journal Science. Experts are confident that the chemicals they analysed were not the result of contamination from the Earth. Mark Sephton, a geochemist at Imperial College London, who was not involved in the study told The Scientist: 'It’s real evidence of hydro-synthesis occurring in asteroids and creating compounds that might be biologically useful,' The four-metre-wide Tagish Lake meteorite exploded after heating up as it passed through the atmosphere 30 to 50 kilometres above the Earth. Pieces of the rock rained down on the frozen, snow-covered lake where they were preserved in sub-zero temperatures. Water in the parent asteroid altered the organic compounds buried within it, leaving signatures that could be read in the meteorite fragments. They indicated that the organic material had existed and undergone chemical processing since the birth of our solar system. - Daily Mail.
