Either space is weirder than we thought, or NASA ripped off The Fantastic Four. According to a study published by the space agency, space travel can permanently alter your DNA. Identical twin astronauts Scott and Mark Kelly were observed over the course of a year after Scott touched down on Earth after a yearlong stay on the International Space Station. The Twins Study is part of an ongoing NASA effort called the Human Research Project which studies the effects of space on the human body in preparation for eventual manned missions to Mars and other prolonged trips through the void.

Identical twins have almost identical DNA, which makes them ideal candidates for studying the mental and physical health effects of space: any changes in the space-faring twin’s physical health would have to be caused by an outside force and not due to natural variation. Identical twins are rare, and astronauts even rarer; luckily NASA has plenty of the latter and two of the former. It was Scott Kelly himself who suggested NASA use him and his brother Mark as test subjects.

What they found is quite strange. While many of the changes to Scott’s physiology returned to normal soon after returning to Earth, they found permanent changes as well. It seems that 7% of Scott Kelly’s DNA has been altered permanently. NASA has speculated on the existence of a “space gene,” which might be activated by conditions in space, causing changes in DNA. NASA says the changes to Scott’s DNA “related to his immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia.” Whether these changes were seen as positive or negative were not said. We may have an answer if the retired astronaut suddenly begins a career as a vigilante superhero, or if it turns out he’s the mothman.

Predictions for the Twins Study were also proven wrong. Telomeres are components of chromosomes that shorten with age, and NASA expected the radiation of space to accelerate that shortening. They found, however, that Scott’s telomeres actually lengthened during his stay on the ISS. They returned to normal within two hours of his return to Earth, however, squashing any hope there might have been for finding the space-fountain of youth.

There were other findings, too. While on the ISS, Scott’s gut bacteria changed dramatically. It returned to normal once back on solid ground, and scientists do not know whether it was differences in the food he ate or environmental factors, such as gravity and radiation, which were responsible. NASA also studied Scott’s mental abilities. Being in space had no effect on his cognition, yet after returning to Earth his mental speed and accuracy began showing slight decreases. Perhaps this is due to returning from a year of peace and quiet in space to a life of medical tests and interviews on terra firma.

While NASA may be furthering the goals of the human species and finding us a way off this rock, they apparently don’t have the best bedside manners. Scott says that he found out about the results of the study the same way as everyone else.

“I did read in the newspaper the other day… that 7 percent of my DNA had changed permanently,” Kelly said. “And I’m reading that, I’m like, ‘Huh, well that’s weird.’”

The full results of the study will be released later in 2018.