Tardigrades Endure Extremes, Within Limits

Tardigrades can survive desiccation, severe cold, vacuum, and certain radiation exposures. Many record-setting results come from animals in anhydrobiosis—a dehydrated state in which metabolism nearly stops. Tolerance depends on species, exposure time, and the stress involved: active tardigrades, for example, are more vulnerable to high temperatures, and solar ultraviolet radiation reduced survival in a space experiment. This does not mean they are invulnerable. The illustration is AI-generated.