Mutations acquired during a lifetime are far more common that commonly believed; it's a key aspect of ageing. The astronauts in this study had an average age of

Mutations acquired during a lifetime are far more common that commonly believed; it's a key aspect of ageing. The astronauts in this study had an average age of 44, by which time they would be expected to have acquired mutations under normal, earthbound, conditions. To address this, the study compares the number of mutations found in the astronauts with the number found in a broader population with mean age of 58 yrs. Notably, they do not conclude that more mutations were found in the astronauts.