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These Twins Prove That Being An Astronaut Doesn’t Stop A Sibling Rivalry

They may be astronauts, but they are also siblings.

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Here are Mark and Scott Kelly. Scott is an astronaut currently spending a year in space. Mark is a former astronaut here on Earth. They are twins.

Robert Markowitz / NASA

Mark is on the left, Scott is on the right. The fact that they are twins is super helpful to NASA, who will use Mark as a control while his identical twin brother experiences space for a year, giving scientists insight into what being in zero-gravity for long periods of time does to a human.


Science Writer, Fossil Beastmaster

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