Every lungful of air we suck down is mostly made up of nitrogen, with a generous helping of oxygen, and a dash of carbon dioxide.

But dusting this atmospheric soup is a whole encyclopedia of different compounds and elements, some of which we can only speculate about.

One of those mysteries just came into focus, however. Chemists have shown that a reactive class of compounds called organic hydrotrioxides exists in the atmosphere, and while these chemicals last only briefly, they could have effects we don’t know about.