Twins are a rare and wonderful thing.
Just imagine having a total duplicate of you roaming around. While all of us are unique, twins are always in this adventure called life together.
But aside from the double takes and pranks that only identical twins can pull off, what else can we learn from them?
Now-retired NASA astronaut Scott Kelly and his twin brother Mark Kelly became part of one of the coolest experiments NASA has ever carried out when Scott began his famous #YearInSpace trip back in March of 2015. The only siblings to have traveled in space, Scott and Mark were the perfect test subjects to compare the effects a year in space has on a human body as compared to a normal year on Earth.
The results are in, and this test was seriously fascinating.
Meet the Twins
Scott and Mark Kelly are an exceptional pair of twins.
Born on February 21, 1964 in Orange, New Jersey, both men hold the rank of Captain in the US Navy and both have served multiple missions in outer space as NASA astronauts. Not too shabby!
You might also know Mark as the husband of former U.S. Representative Gabrielle Giffords (D-Arizona), who survived an attempted assassination in 2011 near Tucson. Thankfully, she has recovered extraordinarily well.
But in their later years (career-wise), the Kellys have become best known for Scott’s year in space aboard the International Space Station and for the twin test conducted on both brothers before, during, and after this time.
Scientists have long studied astronauts to learn about the effects of space on the human body. Typically, these include certain bones being stretched out or muscles rapidly shrinking. It’s also tricky for our circadian rhythm since you’re no longer operation on Earth days and hours.
But the Kellys were a unique opportunity for NASA to study the long-term effects of life in space on the human body with a control. Scott would spend a year in space, and Mark stayed on Earth.
Now that some results of the Twins Study have been released, here are some of the noticeable difference scientists found.
For starters, Scott returned to Earth a full two inches taller than he was when he left! Probably not a great feeling for Mark…
Here are some of the other big changes! Keep reading.