Monday, September 28, 2009
Not All Bad
A comet hitting Earth does more than bring death and destruction - at least that is what researchers at the SETI Institute are trying to prove. Comets could promote certain necessary chemical steps for the origin of life - particularly how comet collisions might have influenced biology's molecular chirality (handed-ness).
Most amino acids, the building blocks of life, exist in 'left-handed' and 'right-handed' forms. Life makes and uses only 'left-handed' amino acids. Comets could have not only helped form, but also bring a massive supply of amino acids to earth to begin the process of life. Comets also carry water with them.