What happens to your body after almost a year in space? Much Most things will return to normal when you get back to Earth – but not all.
This is the extremely topline summary of the NASA study Twins Study, the results of which were published in Science magazine on Friday.
The study followed astronaut Scott Kelly's physiological and cognitive changes as he spent 340 days in space, then compared it to his twin brother Mark Kelly, who is also a retired astronaut.
NASA collected and analyzed 31
Although 559 people have gone into space, only eight have spent more than 300 consecutive days in orbit. This has led to a lack of information about what happens to the human body in weightlessness over time – important information if NASA is serious about sending people to Mars in the coming decades. A trip to the Red Planet takes about 300 days.
Scott returned to Earth about three years ago, and he has largely returned to his normal self, NASA found, including his immune system, his perception, and his microbiome. However, 7% of its gene expression can not return to pre-flight status, possibly due to DNA damage due to increased radiation exposure.
And to another genetic surprise, the ends of the Scott chromosomes – a protective sequence called telomeres – actually elongated in space. Typically, these become shorter with age, and their length is related to age-related health risks such as heart disease and cancer.
"So we certainly envisioned in the study that the unique stresses and the environment are extreme exposures like space radiation and microgravity – all of these things would accelerate telomere loss," said Susan Bailey, researcher at Colorado State University and co-author "We were surprised."
But Bailey warned against raising hopes that NASA had stumbled upon a cure for aging.
"I do not think so [the elongation] can really be considered a fountain of youth "that people may live longer because they are in outer space," she said.
NASA found that Scott Telomeres was "shortened" on Earth within days of landing. It is unclear why this is exactly the case, even if the explanation is downright earthly: Scott's diet in space contained more folic acid (Vitamin B9), which probably played a role.
Overall, however, the NASA researchers were encouraged by the findings.
"" The end result is, "Scott said to Space.com," from all these studies – and of course this is an experiment with a single data point … would be that we did not see anything that would stop us from going to Mars to go. "