Is It Really Alive? This Tiny Microbe Is Challenging Everything We Know About Life

 It’s minuscule, dependent, and astonishingly mysterious—but is it truly alive? That’s the question scientists are now asking after the discovery of Sukunaarchaeum mirabile, a strange microbe found in marine plankton. Uncovered by Canadian and Japanese researchers, this microscopic organism relies so heavily on a living host that it blurs the line between viruses and cellular life. The findings could rewrite our understanding of what it means to be alive.