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They call it the ‘perfect nature versus nurturing’ experiment: Astronaut Scott Kelly was sent to the International Space Station for almost a year, while his identical twin, astronaut and now Senator Mark Kelly, remained on Earth. When Scott Kelly came home in March 2016, scientists compared his DNA and body composition with those of his twins and found that Scott was 2 centimeters taller than he was, and they boasted, among other things, a lower body mass (of which the most since turned back). Now, according to a study published in the journal Monday Circulation, announced another major shift: The mass of Kelly’s heart shrank during his cosmos, from 6.7 ounces to 4.9 ounces, or about 27%, although the astronaut apparently had no major consequences. “He has performed remarkably well for more than a year,” said co-author Benjamin D. Levine, a professor of internal medicine at the University of Texas at Southwestern Medical Center. New York Times.
CNN’s explanation: When people are dealing with the gravity of the earth, the heart has to work harder to pump blood. In gravity, however, the heart does not have to work as hard and therefore perishes. Levine tells the Times that Kelly’s heart did it without becoming ‘dysfunctional’. The study also looked at Benoit Lecomte, an endurance swimmer who tried to cross the Pacific in 2018. The buoyancy of the water and the almost constant horizontal state of Lecomte during his five months of swimming produced conditions similar to Kelly’s weightlessness, and his heart decreased size almost as fast. Although Kelly ended up being good, he also worked quite a bit in space using workout clothes, which probably kept his heart from weakening further. Scientists are concerned that astronauts will not be able to practice on future missions due to injuries, illnesses or broken equipment and that this will have more serious consequences. NASA is funding further research on the heart in which astronauts are involved in long and short-distance travel. (Read more discovery stories.)