The Twin Study mission scientists released the final results of the comparison of physical health of two twins, Scott and Mark Kelly.
The study was conducted in 2015-2016. Experts closely monitored physiological parameters of Scott, who was in orbit (his blood system, brain, etc.). When the astronaut returned home, his blood was compared to the blood of his twin brother.
The data analysis revealed many differences. For example, Scott’s telomeres at the ends of chromosomes in his white blood cells got longer in space, compared to Mark’s telomeres, but they returned to about the same average length once the astronaut returned to the ground. In addition, space travel affected gene expression.
Experts say the results of the study confirm the amazing ability of the human body to adapt to various external conditions.