What career will two-time Olympic decathlete gold medalist Ashton Eaton pursue now that he has retired from his sport at age 28? This is what he has written on his Twitter profile: "I'm deciding what to do next. Being the 1st person on Mars would be cool."
And the thing is, going to Mars is not a joke.
"That is a pretty serious idea and goal of mine," Eaton told ESPN.com over the phone after he and his wife, heptathlete Brianne Theisen-Eaton, both announced their retirements Wednesday. "But I have to think about my family, my future, the family I might have one day with kids. And Brianne is not too thrilled about it. Because especially if you are on the first spaceship, there is a good chance you won't make it. Do I really want to put my family through that?"
Perhaps not, though this desire is revealing of Eaton's wide interests beyond sports. And if he did want to pursue such an incredible goal, as Eaton's coach Harry Marra says, do not to put anything past him.
"He never put limits on how far he could jump or fast how he could run," Marra said. "When they go to the meet, the goal was never, 'I'm going to jump 25 feet.' It was always, 'I'm going to try to jump out of the landing pit.'"
The Olympic decathlon champion is often regarded as the world's greatest athlete. After Eaton won his first gold medal at the 2012 London Games, though, a reporter asked him who was the better athlete, Usain Bolt or himself. U.S. decathlon silver medalist Trey Hardee quickly interrupted to answer for the ever-modest Eaton. "Just so Ashton doesn't have to sound selfish or self-centered, Ashton is the best athlete to ever walk the planet," Hardee said. "Hands down.''
Even Bolt agreed that night, saying. "I'm a great athlete, but to do 10 events, especially the 1,500? I've got to give it to him."
To further solidify the title of World's Greatest Athlete, Eaton won his second gold medal in Rio last summer while Theisen-Eaton took bronze in the heptathlon. It was an astounding accomplishment for the married couple. Only two other men have won two gold medals in the decathlon: Daley Thompson and Bob Mathias. Eaton also is the world-record holder in the event, with 9,045 points at the 2015 World Championships.
"He didn't just do it; he did it easily," 1996 Olympic decathlete champion Dan O'Brien said of Eaton's medals. "He dominated the event like nobody else did. ... To compare his accomplishment to another sport -- it's like a dynasty team in football. That's as good as he was. He did everything the Dallas Cowboys did in their dynasty. And the 49ers, too. It was complete dominance.
"If you were going to make a bet on one track and field outcome, even more than Usain Bolt winning, Ashton Eaton would be the best pick on the board."
U.S. 2016 Olympic decathlete Jeremy Taiwo said people don't understand everything Eaton accomplished and that he did not get the proper attention, either.
"Yeah, Usain Bolt is dominant in his events, but Ashton is the best athlete in the world," he said. "The best athlete we've seen in decades. Maybe in a century."
Why then is he retiring at age 28? Eaton said he has had many injuries over the past year and felt as if his body was beginning to shut down. He added that he has accomplished all he can and that his feeling for the sport had dropped to a point at which "it will not be the real me. My mind will be elsewhere, wondering what else I want to do."
What he wants to do -- beyond reaching Mars -- is pursue a career in his other interests: science, technology, education and energy.
Asked where he thinks he'll be in 10 years, Eaton said that if nothing went wrong, "I would open up a university of sorts or develop a new curriculum to help young people create conditions where they can maximize their potential. I'd have, or be working on, some sort of transportation infrastructure revolution.
In addition to those interests, Eaton and his wife also are contributors to charities such as Right to Play and World Vision.
"When doing things that help other people, you end up getting helped more,'' Eaton said. "You just want to do more. It's a really cool cycle''
Whatever Eaton does, it will be worth following.
"Ashton and Brianne are tremendous athletes and tremendous role models for others, but they can continue in life to be role models," Marra said. "I know they both want to do something that makes an impact on humanity and mankind. Whatever it is, they will do well. They will do well -- and do it for other people."
As Eaton has proved, anything is possible. Perhaps The World's Greatest Athlete will someday be "Mars' Greatest Athlete."
"Maybe I'll host the first track meet there or find somebody to fund the first Martian track meet," Eaton said with a laugh. "That would be cool.''