Amino acids could have found their way from deep space to start life on Earth, say scientists in Italy.
 
Piero Ugliengo and Albert Rimola from the University of Turin used quantum mechanics to show that amino acids synthesised in deep space molecular clouds can be captured by interstellar dust particles. Ugliengo says that the particles could have travelled to Earth, where the amino acids were released into the 'primordial soup' ready for the synthesis of early proteins.  

Ugliengo and Rimola simulated the reaction between the amino acid glycine and interstellar silica dust. Their calculations show that glycine can bond to defects on the silica particles' surface - defects that could have been caused by extreme heat given off by young stars. They tested the particles' stability by simulating conditions in space, such as cosmic rays and UV radiation. They also showed that hydrolysis of the particles, which would have happened when the dust landed in the ocean, released the glycine to become part of the primordial soup.

Ugliengo says that he hopes that experimental evidence will match their findings. 'The key role of the mineral surfaces as a catalyst in the prebiotic era is a very broad and promising one,' he says. 'We need to merge accurate quantum-mechanical modelling studies with carefully designed experimental measurements if any real progress in this exciting field is to be seen.' 

'This work not only helps us understand the survival of amino acids formed in the harsh conditions of the interstellar medium, but it also suggests that some of these compounds may have arrived intact to the primitive Earth,' says Antonio Lazcano, a leading scientist in the origin of life and prebiotic chemistry fields, National Autonomous University of Mexico, Mexico City. 'The primitive soup was likely formed by chemical reactions that took place on the Earth but it was clearly spiced by extraterrestrial compounds arriving on board micrometeorites. The richer the broth, the tastier it becomes!' 

Sarah Dixon

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