How a year in space changed his body

What happens to the human body after a year on the International Space station, floating in zero gravity? The Twins Study -- comparing data from before, during and after astronaut Scott Kelly's mission in space with those of his identical twin brother, retired astronaut Mark, back on Earth -- is giving researchers a better idea than ever before.

source CNN.com - RSS Channel - World http://ift.tt/2kS0wDg