NASA officials responded to his sweet and earnest handwritten letter, thrilling Walters and his mother, Katrina Anderson, Fast Company reports.
"I heard that you are sending two people to Mars and I would like to come, but I'm 7 so I can't," Dexter wrote in his letter. "I would like to come in the future. What do I need to do to become an astronaut?"
Dexter and his mother read about NASA's proposed one-way Mars missions on Reddit, Anderson said. When NASA wrote back, she posted the surprise letter from the U.S. space agency on the website for all to see, sparking more than 2,100 comments and an outpouring of support for the boy's interest in science.
"I ran into the room and said 'It's for me! It's for me!' " Dexter told Fast Company of the official package from NASA, which encouraged his interest in space and included pictures and materials to help him learn more about the Red Planet and space exploration.
"Just think – in a few years, you could be one of the pioneers that may help lead the world's activities for better understanding our earth and for exploring space," NASA officials wrote.
The letter, which mom and son read together, also sparked a discussion about the boy's future, Anderson said. "We sat and discussed whether a one-way trip to Mars would be a good idea, and he said he would definitely want to go."
Anderson is certainly supportive if a little hesitant. "I think in the future I will lose him to an American university," she says. "But that's not the end of the Earth. It's not Mars, is it?"