The 2026 Nobel Prize in Chemistry went to Henri B. Kagan and Kenso Soai for solving a century-old puzzle: why does life use only one mirror image of molecules?

Many molecules, like amino acids, come in two forms that are mirror images, called chiral pairs. Yet living things use almost exclusively one form. This one-handedness is called homochirality.

Kagan, of Université Paris-Sud in France, and Soai, 95, of Tokyo University of Science, discovered non-linear effects and autocatalysis in asymmetric synthesis. In plain terms, they found reactions where a tiny initial imbalance snowballs into a product of single handedness.

The famous "Soai reaction" can amplify a nearly invisible chiral trace into a fully one-handed product, offering a possible explanation for how life's single-handedness emerged.

The work also transformed drug manufacturing: in pharmaceuticals, often only one mirror image has the desired effect.

The Royal Swedish Academy of Sciences announced the prize on October 7 in Stockholm. The duo share 12 million Swedish kronor, about $1.2 million.