Scott Kelly's year in space: the twin study

Soon after NASA astronaut Scott Kelly came back on earth after spending a year in space, the scientists will now be conducting tests to study what spending a year in space does to a person. While Scott Kelly spent a year in space his identical twin, Mark stayed on earth. Now the scientists will study what changes took place in his body while in space. Though some of the changes were quite apparent such as Scott Kelly is now two inches taller than his brother. The weightlessness of space is thought to have pulled out Commander Kelly’s spine — which means that his extra height will gradually disappear.

His one year in space for a step towards sending humans to Mars one day. Higher chances of weaker bones and muscles are also there that can become dangerous for people once they make their way back onto Earth. Kelly also served as part of a twin study, parallel twin study which means that the twins one on earth the other in space, their bodily changes will be studied over the period of time.

Gravity also has its effects on human body. Being outside of the Earth’s atmosphere increases the exposure to radiation — the effects of which on humans still isn’t fully understood.

Kelly, who is retiring from Nasa in April, said he hoped the move would allow him to be a better advocate for human space exploration. Kelly would continue to work with Nasa, including on the twin study for which he and his brother are subjects.