Physicists have found hints that the asymmetry of life – the fact that most biochemical molecules are ‘left-handed’ or ‘right-handed’ – could have been caused by electrons from nuclear decay in the early days of evolution. In an experiment that took 13 years to perfect1, the researchers have found that these electrons tend to destroy certain organic molecules slightly more often than they destroy their mirror images.

Chiral molecules are “handy” molecules. Here’s how they’re helping us discover where else life might exist and how it originated on Earth.