Unless you’ve been living under a rock, you’ve probably heard of Scott Kelly by now. Kelly is a current NASA astronaut and he happens to have a twin brother, former astronaut Mark Kelly.

 

Well, there was a rumor going around that while Scott Kelly spent his year in space, he came back with substantial changes to his DNA. These “changes” were so substantial (apparently his DNA makeup changed b almost 7%) that his DNA code no longer matched his twin brother.

 

On March 10, 2018, Scott Kelly tweeted, “What? My DNA changed by 7%! Who knew? I just learned about it in this article. This could be good news! I no longer have to call [Mark Kelly] my identical twin brother anymore.”

 

Well, we hate to be the bearer of bad news, but this information is completely FALSE. No, 7% of Kelly’s DNA was NOT altered while he spent a year in space. People initially thought that a result was measuring Kelly’s genetic sequences, when in fact, the result was actually measuring his expression levels, which naturally would change during spaceflight.

 

Lastly, to end this on a slightly ironic note, even if Scott Kelly’s genetic sequences HAD changed in space, they were already different than his brother’s. They are fraternal twins.