New Evidence That Life On Earth Was Forged in Outer Space
Two new studies published in the past week lend more weight to the theory that life, or at least its constituent parts, came from outer space. One bolsters the theory that left-handedness prevails in the cosmos, and another explains how the building blocks of life became left-handed in the first place. Many amino acids, sugars and other molecular building blocks of life are chiral, meaning they have left-handed and right-handed versions. Like your hands, these are mirror opposite pairs that cannot be superimposed on each other. There's really no reason for one to prevail over the other, but this symmetry breaking happens anyway; life on Earth is largely left-handed (though a recent study suggests its lower forms can be ambidextrous). In 2009, NASA researchers studied meteorites and found that left-handedness also seems to prevail throughout the cosmos. Last week, they said this quality can be found in an even wider...